Dosing & Uses
Dosage Forms & Strengths
acetaminophen/aspirin/diphenhydramine
caplet
- 250mg/250mg/38mg (as diphenhydramine citrate; equivalent to 25mg diphenhydramine)
Headache
Indicated for temporary relief of occasional headaches and minor aches and pains with accompanying sleeplessness
2 caplets PO HS prn
Dosage Forms & Strengths
acetaminophen/aspirin/diphenhydramine
caplet
- 250mg/250mg/38mg (as diphenhydramine citrate; equivalent to 25mg diphenhydramine)
Headache
Indicated for temporary relief of occasional headaches and minor aches and pains with accompanying sleeplessness
<12 years: Safety and efficacy not established
≥12 years: 2 caplets PO HS prn
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (4)
- abrocitinib
abrocitinib and aspirin both increase anticoagulation. Contraindicated. Antiplatelet drugs, except for low-dose aspirin (=81 mg qDay), during the first 3 months of treatment are contraindicated.
- dichlorphenamide
dichlorphenamide increases levels of aspirin by unknown mechanism. Contraindicated. Coadministration of dichlorphenamide with high-dose aspirin may increase salicylate levels. Anorexia, tachypnea, lethargy, and coma reported.
- eliglustat
diphenhydramine increases levels of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. If coadministered with strong or moderate CYP2D6 inhibitors, reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive and intermediate metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors.
- mifepristone
aspirin, mifepristone. Other (see comment). Contraindicated. Comment: Aspirin induced antiplatelet activity may induce excessive bleeding after an abortion w/mifepristone (RU 486).
Serious - Use Alternative (31)
- benazepril
aspirin, benazepril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.
- calcium/magnesium/potassium/sodium oxybates
diphenhydramine, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- caplacizumab
caplacizumab, aspirin. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- captopril
aspirin, captopril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.
- eluxadoline
diphenhydramine, eluxadoline. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that cause constipation. Increases risk for constipation related serious adverse reactions.
- enalapril
aspirin, enalapril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.
- fosinopril
aspirin, fosinopril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.
- ibuprofen
ibuprofen decreases effects of aspirin by Other (see comment). Avoid or Use Alternate Drug. Comment: Ibuprofen decreases the antiplatelet effects of low-dose aspirin by blocking the active site of platelet cyclooxygenase. Administer ibuprofen 8 h before aspirin or at least 2-4 h after aspirin. The effect of other NSAIDs on aspirin is not established.
ibuprofen increases toxicity of aspirin by anticoagulation. Avoid or Use Alternate Drug. increases risk of bleeding. - ibuprofen IV
ibuprofen IV increases toxicity of aspirin by anticoagulation. Avoid or Use Alternate Drug. increases risk of bleeding.
ibuprofen IV decreases effects of aspirin by Other (see comment). Avoid or Use Alternate Drug. Comment: Ibuprofen decreases the antiplatelet effects of low-dose aspirin by blocking the active site of platelet cyclooxygenase. Administer ibuprofen 8 h before aspirin or at least 2-4 h after aspirin. The effect of other NSAIDs on aspirin is not established. - isocarboxazid
isocarboxazid increases effects of diphenhydramine by Other (see comment). Avoid or Use Alternate Drug. Comment: Isocarboxazid should not be administered in combination with antihistamines because of potential additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .
- ketorolac
aspirin, ketorolac. Either increases toxicity of the other by pharmacodynamic synergism. Contraindicated.
- ketorolac intranasal
aspirin, ketorolac intranasal. Either increases toxicity of the other by pharmacodynamic synergism. Contraindicated.
- lesinurad
aspirin decreases effects of lesinurad by unspecified interaction mechanism. Avoid or Use Alternate Drug. Aspirin at doses >325 mg/day may decrease lesinurad efficacy. Aspirin doses 325 mg/day or less (ie, for cardiovascular event prophylaxis) does not decrease lesinurad efficacy and can be coadministered.
- lisinopril
aspirin, lisinopril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.
- lonafarnib
acetaminophen will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
- macimorelin
aspirin, macimorelin. unspecified interaction mechanism. Avoid or Use Alternate Drug. Drugs that directly affect the pituitary secretion of growth hormone (GH) may impact the accuracy of the macimorelin diagnostic test. Allow sufficient washout time of drugs affecting GH release before administering macimorelin. .
- measles, mumps, rubella and varicella vaccine, live
aspirin, measles, mumps, rubella and varicella vaccine, live. Mechanism: unspecified interaction mechanism. Avoid or Use Alternate Drug. Risk of Reye's Syndrome with combination; avoid salicylate use for 6 wks after vaccination.
- mefloquine
mefloquine increases toxicity of diphenhydramine by QTc interval. Avoid or Use Alternate Drug. Mefloquine may enhance the QTc prolonging effect of high risk QTc prolonging agents.
- methotrexate
aspirin increases levels of methotrexate by decreasing renal clearance. Avoid or Use Alternate Drug. Caution should be exercised when salicylates are given in combination with methotrexate. Risk for drug interactions with methotrexate is greatest during high-dose methotrexate therapy, it has been recommended that any of these drugs be used cautiously with methotrexate even when methotrexate is used in low doses.
- metoclopramide intranasal
diphenhydramine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
- mifepristone
aspirin will decrease the level or effect of mifepristone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- mitotane
aspirin will decrease the level or effect of mitotane by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- moexipril
aspirin, moexipril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.
- olopatadine intranasal
diphenhydramine and olopatadine intranasal both increase sedation. Avoid or Use Alternate Drug. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.
- pemetrexed
aspirin increases levels of pemetrexed by unspecified interaction mechanism. Avoid or Use Alternate Drug. Interrupt dosing in all patients taking NSAIDs with long elimination half-lives for at least 5d before, the day of, and 2d following pemetrexed administration. If coadministration of an NSAID is necessary, closely monitor patients for toxicity, especially myelosuppression, renal toxicity, and GI toxicity.
- perindopril
aspirin, perindopril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.
- pexidartinib
acetaminophen and pexidartinib both increase Other (see comment). Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.
- pitolisant
diphenhydramine decreases effects of pitolisant by Other (see comment). Avoid or Use Alternate Drug. Comment: Pitolisant increases histamine levels in the brain; therefore, H1 receptor antagonists that cross the blood-brain barrier may reduce the efficacy of pitolisant.
- pramlintide
pramlintide, diphenhydramine. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Synergistic inhibition of GI motility.
- pretomanid
acetaminophen, pretomanid. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Pretomanid regimen associated with hepatotoxicity. Avoid alcohol and hepatotoxic agents, including herbal supplements and drugs other than bedaquiline and linezolid.
- probenecid
aspirin decreases effects of probenecid by acidic (anionic) drug competition for renal tubular clearance. Avoid or Use Alternate Drug. Aspirin decreases uricosuric action of probenecid.
Monitor Closely (536)
- abciximab
aspirin, abciximab. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- acalabrutinib
acalabrutinib increases effects of aspirin by anticoagulation. Modify Therapy/Monitor Closely. Coadministration of acalabrutinib with antiplatelets or anticoagulants may further increase risk of hemorrhage. Monitor for signs of bleeding and consider the benefit-risk of withholding acalabrutinib for 3-7 days presurgery and postsurgery depending upon the type of surgery and the risk of bleeding.
- acebutolol
acebutolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of acebutolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - aceclofenac
aceclofenac and aspirin both increase anticoagulation. Use Caution/Monitor.
aceclofenac and aspirin both increase serum potassium. Use Caution/Monitor. - acemetacin
acemetacin and aspirin both increase anticoagulation. Use Caution/Monitor.
acemetacin and aspirin both increase serum potassium. Use Caution/Monitor. - acetazolamide
acetazolamide, aspirin. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.
acetazolamide, aspirin. Mechanism: passive renal tubular reabsorption due to increased pH. Use Caution/Monitor. Salicylate levels increased at moderate doses; risk of CNS toxicity. Salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid). - aclidinium
diphenhydramine and aclidinium both decrease cholinergic effects/transmission. Use Caution/Monitor.
- acrivastine
acrivastine and diphenhydramine both increase sedation. Use Caution/Monitor.
- agrimony
aspirin and agrimony both increase anticoagulation. Use Caution/Monitor.
- albuterol
diphenhydramine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin increases and albuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - alfalfa
aspirin and alfalfa both increase anticoagulation. Use Caution/Monitor.
- alfentanil
diphenhydramine and alfentanil both increase sedation. Use Caution/Monitor.
- alfuzosin
aspirin decreases effects of alfuzosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- aliskiren
aspirin will decrease the level or effect of aliskiren by Other (see comment). Use Caution/Monitor. In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs with drugs that affect RAAS may increase the risk of renal impairment (including acute renal failure) and cause loss of antihypertensive effect. Monitor renal function periodically.
- alprazolam
diphenhydramine and alprazolam both increase sedation. Use Caution/Monitor.
- alteplase
aspirin, alteplase. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- American ginseng
aspirin and American ginseng both increase anticoagulation. Use Caution/Monitor.
- amantadine
diphenhydramine, amantadine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Potential for increased anticholinergic adverse effects.
- amifampridine
diphenhydramine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.
- amiloride
amiloride and aspirin both increase serum potassium. Modify Therapy/Monitor Closely.
- amisulpride
amisulpride and diphenhydramine both increase sedation. Use Caution/Monitor.
- amitriptyline
diphenhydramine and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.
diphenhydramine and amitriptyline both increase sedation. Use Caution/Monitor. - amobarbital
diphenhydramine and amobarbital both increase sedation. Use Caution/Monitor.
- amoxapine
diphenhydramine and amoxapine both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and amoxapine both increase sedation. Use Caution/Monitor. - amoxicillin
amoxicillin, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
amoxicillin, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor. - ampicillin
ampicillin, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
- anagrelide
aspirin, anagrelide. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; increases risk of bleeding; monitor closely.
anagrelide, aspirin. Either increases toxicity of the other by Mechanism: pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; increases risk of bleeding; monitor closely. - anticholinergic/sedative combos
anticholinergic/sedative combos and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- antithrombin alfa
antithrombin alfa and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
aspirin, antithrombin alfa. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely. - antithrombin III
antithrombin III and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
aspirin, antithrombin III. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely. - apalutamide
apalutamide will decrease the level or effect of acetaminophen by increasing elimination. Use Caution/Monitor. Apalutamide induces UGT and may decrease systemic exposure of drugs that are UGT substrates.
- apixaban
aspirin and apixaban both increase anticoagulation. Modify Therapy/Monitor Closely. Both drugs have the potential to cause bleeding. The need for simultaneous use of low-dose aspirin (<100 mg/day) with anticoagulants are common for patients with cardiovascular disease, but may result in increased bleeding; monitor closely. Promptly evaluate any signs or symptoms of blood loss if treated concomitantly with low-dose aspiriin. Avoid coadministration with chronic use of higher dose aspirin. In 1 trial (APPRAISE-2), therapy was terminated because of significantly increased bleeding when apixaban was administered with dual antiplatelet therapy (eg, aspirin plus clopidogrel) compared with single antiplatelet treatment
- apomorphine
diphenhydramine and apomorphine both increase sedation. Use Caution/Monitor.
- arformoterol
diphenhydramine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin increases and arformoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - argatroban
argatroban and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
aspirin, argatroban. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely. - aripiprazole
diphenhydramine and aripiprazole both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of aripiprazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of aripiprazole by pharmacodynamic antagonism. Use Caution/Monitor.
aripiprazole increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - armodafinil
diphenhydramine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- asenapine
asenapine and diphenhydramine both increase sedation. Use Caution/Monitor.
aspirin decreases effects of asenapine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis. - asenapine transdermal
asenapine transdermal and diphenhydramine both increase sedation. Use Caution/Monitor.
- atenolol
atenolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of atenolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - atogepant
acetaminophen will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- atomoxetine
diphenhydramine will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- atracurium
atracurium and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- atropine
atropine and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- atropine IV/IM
atropine IV/IM and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- avapritinib
acetaminophen will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
avapritinib and diphenhydramine both increase sedation. Use Caution/Monitor. - axitinib
acetaminophen increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- azelastine
azelastine and diphenhydramine both increase sedation. Use Caution/Monitor.
- azficel-T
azficel-T, aspirin. Other (see comment). Use Caution/Monitor. Comment: Patients taking aspirin may experience increased bruising or bleeding at biopsy and/or injection sites. Concomitant use of aspirin is not recommended. .
- azilsartan
aspirin, azilsartan. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals.
aspirin decreases effects of azilsartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect. - baclofen
diphenhydramine and baclofen both increase sedation. Use Caution/Monitor.
- belladonna alkaloids
belladonna alkaloids and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- belladonna and opium
diphenhydramine and belladonna and opium both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and belladonna and opium both increase sedation. Use Caution/Monitor. - bemiparin
bemiparin and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
- benazepril
benazepril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high dose aspirin, in elderly or volume depleted individuals.
- bendroflumethiazide
aspirin increases and bendroflumethiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- benperidol
diphenhydramine and benperidol both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of benperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of benperidol by pharmacodynamic antagonism. Use Caution/Monitor.
benperidol increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - benzhydrocodone/acetaminophen
diphenhydramine will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone [benzhydrocodone is prodrug of hydrocodone]) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.
benzhydrocodone/acetaminophen and diphenhydramine both increase sedation. Use Caution/Monitor. - benzphetamine
diphenhydramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- benztropine
benztropine and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use.
- betaxolol
betaxolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of betaxolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - bethanechol
bethanechol increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- betrixaban
aspirin, betrixaban. Either increases levels of the other by anticoagulation. Use Caution/Monitor.
- bimatoprost
bimatoprost, aspirin. unspecified interaction mechanism. Use Caution/Monitor. There are conflicting reports from studies of either increased or decreased IOP when ophthalmic prostaglandins are coadministered with NSAIDs (either systemic or ophthalmic).
- bisoprolol
bisoprolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of bisoprolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - bivalirudin
bivalirudin and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
aspirin, bivalirudin. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely. - brexanolone
brexanolone, diphenhydramine. Either increases toxicity of the other by sedation. Use Caution/Monitor.
- brexpiprazole
diphenhydramine will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor.
brexpiprazole and diphenhydramine both increase sedation. Use Caution/Monitor. - brimonidine
brimonidine and diphenhydramine both increase sedation. Use Caution/Monitor.
- brinzolamide
brinzolamide, aspirin. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.
- brivaracetam
brivaracetam and diphenhydramine both increase sedation. Use Caution/Monitor.
- brompheniramine
brompheniramine and diphenhydramine both increase sedation. Use Caution/Monitor.
- bumetanide
aspirin increases and bumetanide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin decreases effects of bumetanide by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis. - bupivacaine implant
acetaminophen, bupivacaine implant. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Local anesthetics may increase the risk of developing methemoglobinemia when concurrently exposed to drugs that also cause methemoglobinemia.
- buprenorphine
diphenhydramine and buprenorphine both increase sedation. Use Caution/Monitor.
- buprenorphine buccal
diphenhydramine and buprenorphine buccal both increase sedation. Use Caution/Monitor.
- buprenorphine subdermal implant
buprenorphine subdermal implant and diphenhydramine both increase sedation. Use Caution/Monitor.
- busulfan
acetaminophen increases levels of busulfan by decreasing metabolism. Use Caution/Monitor. Use of acetaminophen prior to (< 72 hours) or concurrently with busulfan may result in decreased clearance of busulfan due to acetaminophen-induced decreases in glutathione levels.
- butabarbital
diphenhydramine and butabarbital both increase sedation. Use Caution/Monitor.
- butalbital
diphenhydramine and butalbital both increase sedation. Use Caution/Monitor.
- butorphanol
diphenhydramine and butorphanol both increase sedation. Use Caution/Monitor.
- caffeine
diphenhydramine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- candesartan
candesartan and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of candesartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect.
candesartan, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals. - captopril
captopril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high dose aspirin, elderly or volume depleted individuals.
- carbachol
carbachol increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- carbenoxolone
aspirin increases and carbenoxolone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- carbinoxamine
carbinoxamine and diphenhydramine both increase sedation. Use Caution/Monitor.
- carisoprodol
diphenhydramine and carisoprodol both increase sedation. Use Caution/Monitor.
- carvedilol
carvedilol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of carvedilol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
diphenhydramine will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. - celecoxib
aspirin and celecoxib both increase anticoagulation. Use Caution/Monitor.
aspirin and celecoxib both increase serum potassium. Use Caution/Monitor. - cenobamate
cenobamate, diphenhydramine. Either increases effects of the other by sedation. Use Caution/Monitor.
- celiprolol
celiprolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of celiprolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - cevimeline
cevimeline increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chloral hydrate
diphenhydramine and chloral hydrate both increase sedation. Use Caution/Monitor.
- chlordiazepoxide
diphenhydramine and chlordiazepoxide both increase sedation. Use Caution/Monitor.
- chlorothiazide
aspirin increases and chlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chlorpheniramine
chlorpheniramine and diphenhydramine both increase sedation. Use Caution/Monitor.
- chlorpromazine
diphenhydramine and chlorpromazine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
chlorpromazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - chlorpropamide
aspirin increases effects of chlorpropamide by unknown mechanism. Use Caution/Monitor. Risk of hypoglycemia.
- chlorthalidone
aspirin increases and chlorthalidone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chlorzoxazone
diphenhydramine and chlorzoxazone both increase sedation. Use Caution/Monitor.
- choline magnesium trisalicylate
aspirin and choline magnesium trisalicylate both increase anticoagulation. Use Caution/Monitor.
aspirin and choline magnesium trisalicylate both increase serum potassium. Use Caution/Monitor. - cilostazol
aspirin, cilostazol. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- cinnamon
aspirin and cinnamon both increase anticoagulation. Use Caution/Monitor.
- cinnarizine
cinnarizine and diphenhydramine both increase sedation. Use Caution/Monitor.
- ciprofloxacin
aspirin decreases levels of ciprofloxacin by Other (see comment). Use Caution/Monitor. Comment: Buffered aspirin may decrease absorption of quinolones. Consider administering 2 hr before or 6 hr after, buffered aspirin administration.
- cisatracurium
cisatracurium and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- citalopram
citalopram, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. If possible, avoid concurrent use.
- clemastine
clemastine and diphenhydramine both increase sedation. Use Caution/Monitor.
- clobazam
diphenhydramine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).
- clomipramine
diphenhydramine will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
clomipramine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. Clomipramine inhib. serotonin uptake by platelets.
diphenhydramine and clomipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and clomipramine both increase sedation. Use Caution/Monitor. - clonazepam
diphenhydramine and clonazepam both increase sedation. Use Caution/Monitor.
- clopidogrel
aspirin, clopidogrel. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- clorazepate
diphenhydramine and clorazepate both increase sedation. Use Caution/Monitor.
- clozapine
diphenhydramine and clozapine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of clozapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of clozapine by pharmacodynamic antagonism. Use Caution/Monitor.
clozapine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - codeine
diphenhydramine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
diphenhydramine and codeine both increase sedation. Use Caution/Monitor. - collagenase clostridium histolyticum
aspirin increases toxicity of collagenase clostridium histolyticum by anticoagulation. Use Caution/Monitor. Collagenase clostridium histolyticum has high incidence of ecchymosis/contusion at injection site; avoid concomitant anticoagulants (except for low-dose aspirin, ie, up to 150 mg/day).
- cordyceps
aspirin and cordyceps both increase anticoagulation. Use Caution/Monitor.
- cortisone
aspirin, cortisone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.
- cyclizine
cyclizine and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
cyclizine and diphenhydramine both increase sedation. Use Caution/Monitor. - cyclobenzaprine
cyclobenzaprine and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and cyclobenzaprine both increase sedation. Use Caution/Monitor. - cyclopenthiazide
aspirin increases and cyclopenthiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- cyproheptadine
cyproheptadine and diphenhydramine both increase sedation. Use Caution/Monitor.
- dabigatran
dabigatran and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely. Both drugs have the potential to cause bleeding. The need for simultaneous use of low-dose aspirin (<100 mg/day) with anticoagulants are common for patients with cardiovascular disease, but may result in increased bleeding; monitor closely. Promptly evaluate any signs or symptoms of blood loss if treated concomitantly with low-dose aspirin. Avoid coadministration with chronic use of higher dose aspirin
- dalteparin
dalteparin and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
aspirin, dalteparin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely. - dantrolene
diphenhydramine and dantrolene both increase sedation. Use Caution/Monitor.
- dapsone topical
acetaminophen increases toxicity of dapsone topical by altering metabolism. Modify Therapy/Monitor Closely. May induce methemoglobinemia .
- daridorexant
diphenhydramine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.
- darifenacin
darifenacin and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- deferasirox
deferasirox, aspirin. Other (see comment). Use Caution/Monitor. Comment: Combination may increase GI bleeding, ulceration and irritation. Use with caution.
- defibrotide
defibrotide increases effects of aspirin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Defibrotide may enhance effects of platelet inhibitors.
- deflazacort
aspirin, deflazacort. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.
- desflurane
desflurane and diphenhydramine both increase sedation. Use Caution/Monitor.
- desipramine
diphenhydramine will increase the level or effect of desipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and desipramine both increase sedation. Use Caution/Monitor. - desirudin
aspirin, desirudin. Either increases levels of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- deutetrabenazine
diphenhydramine and deutetrabenazine both increase sedation. Use Caution/Monitor.
- dexamethasone
aspirin, dexamethasone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.
- dexchlorpheniramine
dexchlorpheniramine and diphenhydramine both increase sedation. Use Caution/Monitor.
- dexfenfluramine
diphenhydramine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dexmedetomidine
diphenhydramine and dexmedetomidine both increase sedation. Use Caution/Monitor.
- dexmethylphenidate
diphenhydramine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dextroamphetamine
diphenhydramine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dextromoramide
diphenhydramine and dextromoramide both increase sedation. Use Caution/Monitor.
- diamorphine
diphenhydramine and diamorphine both increase sedation. Use Caution/Monitor.
- diazepam
diphenhydramine and diazepam both increase sedation. Use Caution/Monitor.
- diazepam intranasal
diazepam intranasal, diphenhydramine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.
- diclofenac
aspirin and diclofenac both increase anticoagulation. Use Caution/Monitor.
aspirin and diclofenac both increase serum potassium. Use Caution/Monitor. - dicloxacillin
dicloxacillin, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
- dicyclomine
dicyclomine and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- diethylpropion
diphenhydramine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- difelikefalin
difelikefalin and diphenhydramine both increase sedation. Use Caution/Monitor.
- difenoxin hcl
diphenhydramine and difenoxin hcl both increase sedation. Use Caution/Monitor.
- diflunisal
aspirin and diflunisal both increase anticoagulation. Use Caution/Monitor.
aspirin and diflunisal both increase serum potassium. Use Caution/Monitor. - digoxin
aspirin and digoxin both increase serum potassium. Use Caution/Monitor.
- dimenhydrinate
dimenhydrinate and diphenhydramine both increase sedation. Use Caution/Monitor.
- diphenoxylate hcl
diphenhydramine and diphenoxylate hcl both increase sedation. Use Caution/Monitor.
- dipipanone
diphenhydramine and dipipanone both increase sedation. Use Caution/Monitor.
- dipyridamole
aspirin, dipyridamole. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- dobutamine
diphenhydramine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin increases and dobutamine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - donepezil
donepezil increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dong quai
aspirin and dong quai both increase anticoagulation. Use Caution/Monitor.
- donepezil transdermal
donepezil transdermal, diphenhydramine. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.
- dopamine
diphenhydramine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dopexamine
aspirin increases and dopexamine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
diphenhydramine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - dosulepin
diphenhydramine and dosulepin both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and dosulepin both increase sedation. Use Caution/Monitor. - doxazosin
aspirin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- doxepin
diphenhydramine and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and doxepin both increase sedation. Use Caution/Monitor. - doxylamine
diphenhydramine and doxylamine both increase sedation. Use Caution/Monitor.
- droperidol
diphenhydramine and droperidol both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of droperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of droperidol by pharmacodynamic antagonism. Use Caution/Monitor.
droperidol increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - drospirenone
drospirenone and aspirin both increase serum potassium. Modify Therapy/Monitor Closely.
- duloxetine
duloxetine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.
diphenhydramine will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. - echothiophate iodide
echothiophate iodide increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- edoxaban
edoxaban, aspirin. Either increases toxicity of the other by anticoagulation. Modify Therapy/Monitor Closely. Both drugs have the potential to cause bleeding. The need for simultaneous use of low-dose aspirin (<100 mg/day) with anticoagulants are common for patients with cardiovascular disease, but may result in increased bleeding; monitor closely. Promptly evaluate any signs or symptoms of blood loss if treated concomitantly with low-dose aspirin. Avoid coadministration with chronic use of higher dose aspirin.
- eltrombopag
eltrombopag increases levels of acetaminophen by decreasing metabolism. Use Caution/Monitor. UGT inhibition; significance of interaction unclear.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF, aspirin. Either increases toxicity of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine and tenofovir with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- enalapril
enalapril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high dose aspirin, in elderly or volume depleted individuals.
- enoxaparin
enoxaparin and aspirin both increase anticoagulation. Use Caution/Monitor. Additive effects are intended when both drugs are prescribed as indicated for unstable angina, non-Q-wave MI, and STEMI
aspirin, enoxaparin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely. - ephedrine
aspirin increases and ephedrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
diphenhydramine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - epinephrine
aspirin increases and epinephrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
diphenhydramine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - epinephrine racemic
diphenhydramine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin increases and epinephrine racemic decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - epoprostenol
aspirin and epoprostenol both increase anticoagulation. Use Caution/Monitor.
- esketamine intranasal
esketamine intranasal, diphenhydramine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.
- eprosartan
eprosartan and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of eprosartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect.
eprosartan, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals. - eptifibatide
aspirin, eptifibatide. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- escitalopram
escitalopram, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.
- esmolol
esmolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of esmolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - estazolam
diphenhydramine and estazolam both increase sedation. Use Caution/Monitor.
- ethacrynic acid
aspirin increases and ethacrynic acid decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ethanol
diphenhydramine and ethanol both increase sedation. Use Caution/Monitor.
- etodolac
aspirin and etodolac both increase anticoagulation. Use Caution/Monitor.
aspirin and etodolac both increase serum potassium. Use Caution/Monitor. - etomidate
etomidate and diphenhydramine both increase sedation. Use Caution/Monitor.
- exenatide injectable solution
exenatide injectable solution will decrease the level or effect of acetaminophen by unspecified interaction mechanism. Use Caution/Monitor. To avoid potential interaction, give acetaminophen at least 1 hour before or 4 hours after exenatide injection.
- exenatide injectable suspension
exenatide injectable suspension will decrease the level or effect of acetaminophen by unspecified interaction mechanism. Use Caution/Monitor. To avoid potential interaction, give acetaminophen at least 1 hour before or 4 hours after exenatide injection.
- fenbufen
aspirin and fenbufen both increase anticoagulation. Use Caution/Monitor.
aspirin and fenbufen both increase serum potassium. Use Caution/Monitor. - fenfluramine
diphenhydramine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- fennel
aspirin and fennel both increase anticoagulation. Use Caution/Monitor.
- fenoprofen
aspirin and fenoprofen both increase anticoagulation. Use Caution/Monitor.
aspirin and fenoprofen both increase serum potassium. Use Caution/Monitor. - fentanyl
fentanyl, diphenhydramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with anticholinergics may increase risk for urinary retention and/or severe constipation, which may lead to paralytic ileus.
- fentanyl intranasal
fentanyl intranasal, diphenhydramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with anticholinergics may increase risk for urinary retention and/or severe constipation, which may lead to paralytic ileus.
- fentanyl transdermal
fentanyl transdermal, diphenhydramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with anticholinergics may increase risk for urinary retention and/or severe constipation, which may lead to paralytic ileus.
- fentanyl transmucosal
fentanyl transmucosal, diphenhydramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with anticholinergics may increase risk for urinary retention and/or severe constipation, which may lead to paralytic ileus.
- fesoterodine
diphenhydramine and fesoterodine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- feverfew
aspirin and feverfew both increase anticoagulation. Use Caution/Monitor.
- finerenone
acetaminophen will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or moderate CYP3A4 inhibitors. Adjust finererone dosage as needed.
- fish oil
fish oil, aspirin. Other (see comment). Use Caution/Monitor. Comment: Patients taking fish oil and an anticoagulant or other drug affecting coagulation should be monitored periodically due to potential increased risk of bleeding. .
- fish oil triglycerides
fish oil triglycerides will increase the level or effect of aspirin by anticoagulation. Use Caution/Monitor. Prolonged bleeding reported in patients taking antiplatelet agents or anticoagulants and oral omega-3 fatty acids. Periodically monitor bleeding time in patients receiving fish oil triglycerides and concomitant antiplatelet agents or anticoagulants.
- flavoxate
diphenhydramine and flavoxate both decrease cholinergic effects/transmission. Use Caution/Monitor.
- flecainide
diphenhydramine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- flibanserin
diphenhydramine and flibanserin both increase sedation. Modify Therapy/Monitor Closely. Risk for sedation increased if flibanserin is coadministration with other CNS depressants.
acetaminophen will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors. - fludrocortisone
aspirin, fludrocortisone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.
- imatinib
imatinib decreases levels of acetaminophen by decreasing hepatic clearance. Modify Therapy/Monitor Closely. In vitro, imatinib was found to inhibit acetaminophen O-glucuronidation (Ki value of 58.5 micro-M) at therapeutic levels; avoid chronic acetaminophen therapy with imatinib; if occasional acetaminophen administered, do not exceed 1300 mg/day.
- fluoxetine
fluoxetine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.
- fluphenazine
diphenhydramine and fluphenazine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.
fluphenazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - flurazepam
diphenhydramine and flurazepam both increase sedation. Use Caution/Monitor.
- flurbiprofen
aspirin and flurbiprofen both increase anticoagulation. Use Caution/Monitor.
aspirin and flurbiprofen both increase serum potassium. Use Caution/Monitor. - fluvoxamine
fluvoxamine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding SSRIs inhib. serotonin uptake by platelets.
- fondaparinux
fondaparinux and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
- formoterol
diphenhydramine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - forskolin
aspirin and forskolin both increase anticoagulation. Use Caution/Monitor.
- gabapentin
gabapentin, diphenhydramine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
- fosinopril
fosinopril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high dose aspirin, in elderly or volume depleted individuals.
- furosemide
aspirin increases and furosemide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- gabapentin enacarbil
gabapentin enacarbil, diphenhydramine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
- galantamine
galantamine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ganaxolone
diphenhydramine and ganaxolone both increase sedation. Use Caution/Monitor.
- garlic
aspirin and garlic both increase anticoagulation. Use Caution/Monitor.
- gentamicin
aspirin increases and gentamicin decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ginger
aspirin and ginger both increase anticoagulation. Use Caution/Monitor.
- ginkgo biloba
aspirin and ginkgo biloba both increase anticoagulation. Use Caution/Monitor.
- glimepiride
aspirin increases effects of glimepiride by unknown mechanism. Use Caution/Monitor. Risk of hypoglycemia.
- glipizide
aspirin increases effects of glipizide by unknown mechanism. Use Caution/Monitor. Risk of hypoglycemia.
- glyburide
aspirin increases effects of glyburide by unknown mechanism. Use Caution/Monitor. Risk of hypoglycemia.
- glycopyrrolate
diphenhydramine and glycopyrrolate both decrease cholinergic effects/transmission. Use Caution/Monitor.
- glycopyrrolate inhaled
diphenhydramine and glycopyrrolate inhaled both decrease cholinergic effects/transmission. Use Caution/Monitor.
- glycopyrronium tosylate topical
glycopyrronium tosylate topical, diphenhydramine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.
- gotu kola
gotu kola increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- green tea
green tea increases effects of aspirin by pharmacodynamic synergism. Use Caution/Monitor. (Theoretical, due to caffeine content). Combination may increase risk of bleeding.
- griseofulvin
griseofulvin decreases levels of aspirin by unknown mechanism. Use Caution/Monitor.
- haloperidol
diphenhydramine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and haloperidol both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor.
haloperidol increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - hawthorn
hawthorn increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- henbane
diphenhydramine and henbane both decrease cholinergic effects/transmission. Use Caution/Monitor.
- heparin
heparin and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
aspirin, heparin. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely. - homatropine
diphenhydramine and homatropine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- hops
hops increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- horse chestnut seed
aspirin and horse chestnut seed both increase anticoagulation. Use Caution/Monitor.
- huperzine A
huperzine A increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- hyaluronidase
aspirin decreases effects of hyaluronidase by Other (see comment). Use Caution/Monitor. Comment: Salicylates, when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients may require larger amounts of hyaluronidase for equivalent dispersing effect.
diphenhydramine decreases effects of hyaluronidase by Other (see comment). Use Caution/Monitor. Comment: Antihistamines, when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients may require larger amounts of hyaluronidase for equivalent dispersing effect. - hydralazine
aspirin decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- hydrocodone
diphenhydramine will increase the level or effect of hydrocodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.
- hydrochlorothiazide
aspirin increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- hydrocortisone
aspirin, hydrocortisone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.
- hydromorphone
diphenhydramine will increase the level or effect of hydromorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and hydromorphone both increase sedation. Use Caution/Monitor. - hydroxyzine
diphenhydramine and hydroxyzine both increase sedation. Use Caution/Monitor.
- hyoscyamine
diphenhydramine and hyoscyamine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- hyoscyamine spray
diphenhydramine and hyoscyamine spray both decrease cholinergic effects/transmission. Use Caution/Monitor.
- ibrutinib
ibrutinib will increase the level or effect of aspirin by anticoagulation. Use Caution/Monitor. Ibrutinib may increase the risk of hemorrhage in patients receiving antiplatelet or anticoagulant therapies and monitor for signs of bleeding.
- ibuprofen
aspirin and ibuprofen both increase anticoagulation. Use Caution/Monitor.
aspirin and ibuprofen both increase serum potassium. Use Caution/Monitor. - ibuprofen IV
aspirin will increase the level or effect of ibuprofen IV by acidic (anionic) drug competition for renal tubular clearance. Modify Therapy/Monitor Closely.
aspirin and ibuprofen IV both increase anticoagulation. Modify Therapy/Monitor Closely.
aspirin and ibuprofen IV both increase serum potassium. Use Caution/Monitor. - icosapent
icosapent, aspirin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Icosapent may prolong bleeding time; monitor periodically if coadministered with other drugs that affect bleeding.
- iloperidone
diphenhydramine will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and iloperidone both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of iloperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of iloperidone by pharmacodynamic antagonism. Use Caution/Monitor.
iloperidone increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - imatinib
imatinib, aspirin. Either increases toxicity of the other by Other (see comment). Modify Therapy/Monitor Closely. Comment: Imatinib may cause thrombocytopenia; bleeding risk increased when imatinib is coadministered with anticoagulants, NSAIDs, platelet inhibitors, and thrombolytic agents.
- imipramine
diphenhydramine will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and imipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and imipramine both increase sedation. Use Caution/Monitor. - indapamide
aspirin increases and indapamide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- indomethacin
aspirin and indomethacin both increase anticoagulation. Use Caution/Monitor.
aspirin and indomethacin both increase serum potassium. Use Caution/Monitor. - insulin aspart
aspirin increases effects of insulin aspart by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin aspart protamine/insulin aspart
aspirin increases effects of insulin aspart protamine/insulin aspart by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin degludec
aspirin increases effects of insulin degludec by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin degludec/insulin aspart
aspirin, insulin degludec/insulin aspart. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both drugs decrease blood glucose.
- insulin detemir
aspirin increases effects of insulin detemir by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin glargine
aspirin increases effects of insulin glargine by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin glulisine
aspirin increases effects of insulin glulisine by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin inhaled
aspirin increases effects of insulin inhaled by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin isophane human/insulin regular human
aspirin increases effects of insulin isophane human/insulin regular human by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin lispro
aspirin increases effects of insulin lispro by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin lispro protamine/insulin lispro
aspirin increases effects of insulin lispro protamine/insulin lispro by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin NPH
aspirin increases effects of insulin NPH by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- insulin regular human
aspirin increases effects of insulin regular human by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of insulin with high doses of salicylates (3 g/day or more) may increase risk for hypoglycemia. Insulin dose adjustment and increased frequency of glucose monitoring may be required.
- ipratropium
diphenhydramine and ipratropium both decrease cholinergic effects/transmission. Use Caution/Monitor. Due to the poor systemic absorption of ipratropium, interaction unlikely at regularly recommended dosages.
- irbesartan
irbesartan and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of irbesartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect.
irbesartan, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals. - isavuconazonium sulfate
acetaminophen will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- isoniazid
isoniazid will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Use Caution/Monitor.
- isoproterenol
diphenhydramine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin increases and isoproterenol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - ivacaftor
acetaminophen increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .
- kava
kava increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- ketoprofen
aspirin and ketoprofen both increase anticoagulation. Use Caution/Monitor.
aspirin and ketoprofen both increase serum potassium. Use Caution/Monitor. - ketamine
ketamine and diphenhydramine both increase sedation. Use Caution/Monitor.
- ketorolac
aspirin and ketorolac both increase anticoagulation. Use Caution/Monitor.
aspirin and ketorolac both increase serum potassium. Use Caution/Monitor. - ketorolac intranasal
aspirin and ketorolac intranasal both increase anticoagulation. Use Caution/Monitor.
aspirin and ketorolac intranasal both increase serum potassium. Use Caution/Monitor. - ketotifen, ophthalmic
diphenhydramine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.
- labetalol
labetalol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of labetalol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - lasmiditan
lasmiditan, diphenhydramine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.
- latanoprost
latanoprost, aspirin. unspecified interaction mechanism. Use Caution/Monitor. There are conflicting reports from studies of either increased or decreased IOP when ophthalmic prostaglandins are coadministered with NSAIDs (either systemic or ophthalmic).
- latanoprostene bunod ophthalmic
latanoprostene bunod ophthalmic, aspirin. unspecified interaction mechanism. Use Caution/Monitor. There are conflicting reports from studies of either increased or decreased IOP when ophthalmic prostaglandins are coadministered with NSAIDs (either systemic or ophthalmic).
- lemborexant
acetaminophen will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.
lemborexant, diphenhydramine. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects. - levalbuterol
aspirin increases and levalbuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
diphenhydramine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - levonorgestrel oral/ethinylestradiol/ferrous bisglycinate
levonorgestrel oral/ethinylestradiol/ferrous bisglycinate will decrease the level or effect of acetaminophen by unknown mechanism. Use Caution/Monitor.
acetaminophen increases levels of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by decreasing hepatic clearance. Use Caution/Monitor. Coadministration of ascorbic acid and certain combined hormonal contraceptives (CHCs) containing EE may increase plasma EE concentrations, possibly by inhibition of conjugation. - levodopa
diphenhydramine, levodopa. Other (see comment). Use Caution/Monitor. Comment: Anticholinergic agents may enhance the therapeutic effects of levodopa; however, anticholinergic agents can exacerbate tardive dyskinesia. In high dosage, anticholinergics may decrease the effects of levodopa by delaying its GI absorption. .
- levomilnacipran
levomilnacipran, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. SNRIs may further impair platelet activity in patients taking antiplatelet or anticoagulant drugs.
- levorphanol
diphenhydramine and levorphanol both increase sedation. Use Caution/Monitor.
- lisdexamfetamine
diphenhydramine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lisinopril
lisinopril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high dose aspirin, in elderly or volume depleted individuals.
- lithium
aspirin increases levels of lithium by decreasing renal clearance. Use Caution/Monitor.
- lixisenatide (DSC)
lixisenatide (DSC) will decrease the level or effect of acetaminophen by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. GLP1 agonists delay gastric emptying, which may affect absorption of concomitantly administered oral medications. No effects on acetaminophen Cmax and Tmax were observed when acetaminophen was administered 1 hr before lixisenatide. When administered 1 or 4 hr after lixisenatide, acetaminophen Cmax was decreased by 29% and 31% respectively and median Tmax was delayed by 2 and 1.75 hr, respectively.
- lofepramine
diphenhydramine will increase the level or effect of lofepramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and lofepramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and lofepramine both increase sedation. Use Caution/Monitor. - lofexidine
diphenhydramine and lofexidine both increase sedation. Use Caution/Monitor.
- lomitapide
acetaminophen increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.
- loprazolam
diphenhydramine and loprazolam both increase sedation. Use Caution/Monitor.
- lorazepam
diphenhydramine and lorazepam both increase sedation. Use Caution/Monitor.
- lormetazepam
diphenhydramine and lormetazepam both increase sedation. Use Caution/Monitor.
- lornoxicam
aspirin and lornoxicam both increase anticoagulation. Use Caution/Monitor.
aspirin and lornoxicam both increase serum potassium. Use Caution/Monitor. - losartan
losartan and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of losartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect.
losartan, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals. - loxapine
diphenhydramine and loxapine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of loxapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of loxapine by pharmacodynamic antagonism. Use Caution/Monitor.
loxapine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - loxapine inhaled
loxapine inhaled increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
diphenhydramine and loxapine inhaled both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of loxapine inhaled by pharmacodynamic antagonism. Use Caution/Monitor. - lurasidone
lurasidone, diphenhydramine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.
- maprotiline
diphenhydramine and maprotiline both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and maprotiline both increase sedation. Use Caution/Monitor. - marijuana
diphenhydramine and marijuana both increase sedation. Use Caution/Monitor.
- meclizine
diphenhydramine and meclizine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- meclofenamate
aspirin and meclofenamate both increase anticoagulation. Use Caution/Monitor.
aspirin and meclofenamate both increase serum potassium. Use Caution/Monitor. - mefenamic acid
aspirin and mefenamic acid both increase anticoagulation. Use Caution/Monitor.
aspirin and mefenamic acid both increase serum potassium. Use Caution/Monitor. - melatonin
melatonin increases effects of aspirin by anticoagulation. Use Caution/Monitor. Melatonin may decrease prothrombin time.
diphenhydramine and melatonin both increase sedation. Use Caution/Monitor. - meloxicam
aspirin and meloxicam both increase anticoagulation. Use Caution/Monitor.
aspirin and meloxicam both increase serum potassium. Use Caution/Monitor. - meperidine
diphenhydramine and meperidine both increase sedation. Use Caution/Monitor.
- meprobamate
diphenhydramine and meprobamate both increase sedation. Use Caution/Monitor.
- mesalamine
mesalamine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive nephrotoxicity.
- metaproterenol
aspirin increases and metaproterenol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
diphenhydramine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - metaxalone
diphenhydramine and metaxalone both increase sedation. Use Caution/Monitor.
- methazolamide
methazolamide, aspirin. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.
- methadone
diphenhydramine and methadone both increase sedation. Use Caution/Monitor.
- methamphetamine
diphenhydramine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - methocarbamol
diphenhydramine and methocarbamol both increase sedation. Use Caution/Monitor.
- methscopolamine
diphenhydramine and methscopolamine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- methyclothiazide
aspirin increases and methyclothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
- methylenedioxymethamphetamine
diphenhydramine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- methylprednisolone
aspirin, methylprednisolone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.
- metolazone
aspirin increases and metolazone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- metoprolol
metoprolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of metoprolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
diphenhydramine will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. - mexiletine
diphenhydramine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- midazolam intranasal
acetaminophen will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.
- milnacipran
milnacipran, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.
- midazolam
diphenhydramine and midazolam both increase sedation. Use Caution/Monitor.
- midazolam intranasal
midazolam intranasal, diphenhydramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.
- midodrine
diphenhydramine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- mipomersen
mipomersen, acetaminophen. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.
- mirtazapine
diphenhydramine and mirtazapine both increase sedation. Use Caution/Monitor.
- mistletoe
aspirin increases and mistletoe decreases anticoagulation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- modafinil
diphenhydramine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- moexipril
moexipril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high dose aspirin, in elderly or volume depleted individuals.
- morphine
diphenhydramine will increase the level or effect of morphine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and morphine both increase sedation. Use Caution/Monitor. - motherwort
diphenhydramine and motherwort both increase sedation. Use Caution/Monitor.
- moxisylyte
aspirin decreases effects of moxisylyte by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- moxonidine
diphenhydramine and moxonidine both increase sedation. Use Caution/Monitor.
- mycophenolate
aspirin will increase the level or effect of mycophenolate by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.
- nabilone
diphenhydramine and nabilone both increase sedation. Use Caution/Monitor.
- nabumetone
aspirin and nabumetone both increase anticoagulation. Use Caution/Monitor.
aspirin and nabumetone both increase serum potassium. Use Caution/Monitor. - nadolol
nadolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of nadolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - nafcillin
nafcillin, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
nafcillin, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor. - nalbuphine
diphenhydramine and nalbuphine both increase sedation. Use Caution/Monitor.
- naproxen
aspirin and naproxen both increase anticoagulation. Use Caution/Monitor.
aspirin and naproxen both increase serum potassium. Use Caution/Monitor. - nebivolol
nebivolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of nebivolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
diphenhydramine will increase the level or effect of nebivolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. - nefazodone
nefazodone, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.
- neostigmine
neostigmine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- nettle
aspirin increases and nettle decreases anticoagulation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- nitazoxanide
nitazoxanide, aspirin. Either increases levels of the other by Mechanism: plasma protein binding competition. Use Caution/Monitor.
- nitroglycerin rectal
aspirin will increase the level or effect of nitroglycerin rectal by Other (see comment). Use Caution/Monitor. The pharmacological effects of nitroglycerin may be enhanced by concomitant administration of aspirin.
- nitroglycerin sublingual
aspirin increases effects of nitroglycerin sublingual by additive vasodilation. Use Caution/Monitor. Vasodilatory and hemodynamic effects of NTG may be enhanced by coadministration with aspirin (additive effect desirable for emergent treatment).
- norepinephrine
aspirin increases and norepinephrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
diphenhydramine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - nortriptyline
diphenhydramine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and nortriptyline both increase sedation. Use Caution/Monitor. - olmesartan
olmesartan and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of olmesartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect.
olmesartan, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals. - olanzapine
diphenhydramine and olanzapine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
olanzapine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - oliceridine
diphenhydramine will increase the level or effect of oliceridine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.
- omega 3 carboxylic acids
omega 3 carboxylic acids, aspirin. Other (see comment). Use Caution/Monitor. Comment: Patients taking omega-3 acids and an anticoagulant or other drug affecting coagulation should be monitored periodically due to potential increased risk of bleeding.
- omega 3 fatty acids
omega 3 fatty acids, aspirin. Other (see comment). Use Caution/Monitor. Comment: Patients taking omega-3-fatty acids and an anticoagulant or other drug affecting coagulation should be monitored periodically due to potential increased risk of bleeding. .
- onabotulinumtoxinA
onabotulinumtoxinA and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- opium tincture
diphenhydramine and opium tincture both increase sedation. Use Caution/Monitor.
- orphenadrine
diphenhydramine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and orphenadrine both increase sedation. Use Caution/Monitor. - ospemifene
diphenhydramine, ospemifene. Either increases levels of the other by plasma protein binding competition. Modify Therapy/Monitor Closely.
aspirin, ospemifene. Either increases levels of the other by plasma protein binding competition. Modify Therapy/Monitor Closely. - oxacillin
oxacillin, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
oxacillin, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor. - oxazepam
diphenhydramine and oxazepam both increase sedation. Use Caution/Monitor.
- oxaprozin
aspirin and oxaprozin both increase anticoagulation. Use Caution/Monitor.
aspirin and oxaprozin both increase serum potassium. Use Caution/Monitor. - oxybutynin
diphenhydramine and oxybutynin both decrease cholinergic effects/transmission. Use Caution/Monitor.
- oxybutynin topical
diphenhydramine and oxybutynin topical both decrease cholinergic effects/transmission. Use Caution/Monitor.
- oxybutynin transdermal
diphenhydramine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.
- oxycodone
diphenhydramine will increase the level or effect of oxycodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and oxycodone both increase sedation. Use Caution/Monitor. - oxymorphone
diphenhydramine will increase the level or effect of oxymorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
diphenhydramine and oxymorphone both increase sedation. Use Caution/Monitor. - paliperidone
diphenhydramine and paliperidone both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of paliperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of paliperidone by pharmacodynamic antagonism. Use Caution/Monitor.
paliperidone increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - panax ginseng
aspirin and panax ginseng both increase anticoagulation. Use Caution/Monitor.
- pancuronium
diphenhydramine and pancuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.
- papaveretum
diphenhydramine and papaveretum both increase sedation. Use Caution/Monitor.
- papaverine
diphenhydramine and papaverine both increase sedation. Use Caution/Monitor.
- parecoxib
aspirin and parecoxib both increase anticoagulation. Use Caution/Monitor.
aspirin and parecoxib both increase serum potassium. Use Caution/Monitor. - paroxetine
paroxetine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.
- passion flower
passion flower increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- pau d'arco
aspirin and pau d'arco both increase anticoagulation. Use Caution/Monitor.
- pegaspargase
pegaspargase increases effects of aspirin by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of bleeding events.
- penbutolol
penbutolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of penbutolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - penicillin G aqueous
penicillin G aqueous, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
penicillin G aqueous, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor. - pentazocine
diphenhydramine and pentazocine both increase sedation. Use Caution/Monitor.
- pentobarbital
diphenhydramine and pentobarbital both increase sedation. Use Caution/Monitor.
- perampanel
perampanel and diphenhydramine both increase sedation. Use Caution/Monitor.
- perindopril
perindopril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high doses of aspirin,in elderly or volume depleted individuals.
- perphenazine
diphenhydramine and perphenazine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.
perphenazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - phendimetrazine
diphenhydramine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phenelzine
phenelzine increases effects of diphenhydramine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .
- phenindione
phenindione and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
- phenobarbital
diphenhydramine and phenobarbital both increase sedation. Use Caution/Monitor.
- phenoxybenzamine
aspirin decreases effects of phenoxybenzamine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- phentermine
diphenhydramine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phentolamine
aspirin decreases effects of phentolamine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- phenylephrine
diphenhydramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phenylephrine PO
diphenhydramine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
- pholcodine
diphenhydramine and pholcodine both increase sedation. Use Caution/Monitor.
- physostigmine
physostigmine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phytoestrogens
aspirin and phytoestrogens both increase anticoagulation. Use Caution/Monitor.
- pilocarpine
pilocarpine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pimozide
diphenhydramine and pimozide both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of pimozide by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of pimozide by pharmacodynamic antagonism. Use Caution/Monitor.
pimozide increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - pindolol
pindolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of pindolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - pirbuterol
aspirin increases and pirbuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
diphenhydramine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - piroxicam
aspirin and piroxicam both increase anticoagulation. Use Caution/Monitor.
aspirin and piroxicam both increase serum potassium. Use Caution/Monitor. - pralidoxime
diphenhydramine and pralidoxime both decrease cholinergic effects/transmission. Use Caution/Monitor.
- pivmecillinam
pivmecillinam, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
pivmecillinam, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor. - potassium acid phosphate
aspirin and potassium acid phosphate both increase serum potassium. Modify Therapy/Monitor Closely.
- potassium chloride
aspirin and potassium chloride both increase serum potassium. Modify Therapy/Monitor Closely.
- potassium citrate
aspirin and potassium citrate both increase serum potassium. Use Caution/Monitor.
- potassium iodide
potassium iodide and aspirin both increase serum potassium. Use Caution/Monitor.
- prasugrel
aspirin, prasugrel. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- prazosin
aspirin decreases effects of prazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- prednisolone
aspirin, prednisolone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.
- prednisone
aspirin, prednisone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.
- pregabalin
pregabalin, diphenhydramine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
- primidone
diphenhydramine and primidone both increase sedation. Use Caution/Monitor.
- prochlorperazine
diphenhydramine and prochlorperazine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of prochlorperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of prochlorperazine by pharmacodynamic antagonism. Use Caution/Monitor.
prochlorperazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - promethazine
diphenhydramine and promethazine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of promethazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of promethazine by pharmacodynamic antagonism. Use Caution/Monitor.
promethazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - propafenone
diphenhydramine will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- propantheline
diphenhydramine and propantheline both decrease cholinergic effects/transmission. Use Caution/Monitor.
- propofol
propofol and diphenhydramine both increase sedation. Use Caution/Monitor.
- propranolol
diphenhydramine will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
propranolol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of propranolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - propylhexedrine
diphenhydramine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- protamine
protamine and aspirin both increase anticoagulation. Modify Therapy/Monitor Closely.
- protriptyline
diphenhydramine and protriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and protriptyline both increase sedation. Use Caution/Monitor. - pyridostigmine
pyridostigmine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- quazepam
diphenhydramine and quazepam both increase sedation. Use Caution/Monitor.
- quetiapine
diphenhydramine and quetiapine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor.
quetiapine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - quinapril
quinapril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high doses of aspirin, in elderly or volume depleted individuals.
- ramelteon
diphenhydramine and ramelteon both increase sedation. Use Caution/Monitor.
- ramipril
ramipril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high doses of aspirin, in elderly or volume depleted individuals.
- rapacuronium
diphenhydramine and rapacuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.
- reishi
aspirin and reishi both increase anticoagulation. Use Caution/Monitor.
- reteplase
aspirin, reteplase. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- risperidone
diphenhydramine and risperidone both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of risperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of risperidone by pharmacodynamic antagonism. Use Caution/Monitor.
risperidone increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - rivaroxaban
aspirin, rivaroxaban. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. Both drugs have the potential to cause bleeding. The need for simultaneous use of low-dose aspirin (<100 mg/day) with anticoagulants are common for patients with cardiovascular disease, but may result in increased bleeding; monitor closely. Promptly evaluate any signs or symptoms of blood loss if treated concomitantly with low-dose aspirin. Avoid coadministration with chronic use of higher dose aspirin.
- rivastigmine
rivastigmine increases toxicity of aspirin by pharmacodynamic synergism. Use Caution/Monitor. Monitor patients for symptoms of active or occult gastrointestinal bleeding.
- rocuronium
diphenhydramine and rocuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.
- sacubitril/valsartan
sacubitril/valsartan and aspirin both increase serum potassium. Use Caution/Monitor.
sacubitril/valsartan, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals.
aspirin decreases effects of sacubitril/valsartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect. - salicylates (non-asa)
aspirin and salicylates (non-asa) both increase anticoagulation. Use Caution/Monitor.
aspirin and salicylates (non-asa) both increase serum potassium. Use Caution/Monitor. - salmeterol
diphenhydramine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin increases and salmeterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - salsalate
aspirin and salsalate both increase anticoagulation. Use Caution/Monitor.
aspirin and salsalate both increase serum potassium. Use Caution/Monitor. - scopolamine
diphenhydramine and scopolamine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- saw palmetto
saw palmetto increases toxicity of aspirin by unspecified interaction mechanism. Use Caution/Monitor. May increase risk of bleeding.
- scullcap
diphenhydramine and scullcap both increase sedation. Use Caution/Monitor.
- secobarbital
diphenhydramine and secobarbital both increase sedation. Use Caution/Monitor.
- selumetinib
aspirin and selumetinib both increase anticoagulation. Modify Therapy/Monitor Closely. An increased risk of bleeding may occur in patients taking a vitamin-K antagonist or an antiplatelet agent with selumetinib. Monitor for bleeding and INR or PT in patients coadministered a vitamin-K antagonist or an antiplatelet agent with selumetinib.
- sertraline
sertraline, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.
- Siberian ginseng
aspirin and Siberian ginseng both increase anticoagulation. Use Caution/Monitor.
- sevoflurane
sevoflurane and diphenhydramine both increase sedation. Use Caution/Monitor.
- shepherd's purse
diphenhydramine and shepherd's purse both increase sedation. Use Caution/Monitor.
- silodosin
aspirin decreases effects of silodosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- sodium picosulfate/magnesium oxide/anhydrous citric acid
aspirin, sodium picosulfate/magnesium oxide/anhydrous citric acid. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May be associated with fluid and electrolyte imbalances.
- sodium sulfate/?magnesium sulfate/potassium chloride
sodium sulfate/?magnesium sulfate/potassium chloride increases toxicity of aspirin by Other (see comment). Use Caution/Monitor. Comment: Coadministration with medications that cause fluid and electrolyte abnormalities may increase the risk of adverse events of seizure, arrhythmias, and renal impairment.
- sodium sulfate/potassium sulfate/magnesium sulfate
sodium sulfate/potassium sulfate/magnesium sulfate increases toxicity of aspirin by Other (see comment). Use Caution/Monitor. Comment: Coadministration with medications that cause fluid and electrolyte abnormalities may increase the risk of adverse events of seizure, arrhythmias, and renal impairment.
- solifenacin
diphenhydramine and solifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.
- sotalol
sotalol and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of sotalol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - sparsentan
aspirin and sparsentan both increase nephrotoxicity and/or ototoxicity. Use Caution/Monitor. Coadministration of NSAIDS, including selective COX-2 inhibitors, may result in deterioration of kidney function (eg, possible kidney failure). Monitor for signs of worsening renal function with concomitant use with NSAIDs.
- spironolactone
spironolactone and aspirin both increase serum potassium. Modify Therapy/Monitor Closely.
aspirin decreases effects of spironolactone by unspecified interaction mechanism. Use Caution/Monitor. When used concomitantly, spironolactone dose may need to be titrated to higher maintenance dose and the patient should be observed closely to determine if the desired effect is obtained. - stiripentol
stiripentol, diphenhydramine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.
- succinylcholine
aspirin and succinylcholine both increase serum potassium. Use Caution/Monitor.
succinylcholine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor. - sufentanil
diphenhydramine and sufentanil both increase sedation. Use Caution/Monitor.
- sulfamethoxazole
aspirin, sulfamethoxazole. Either increases effects of the other by plasma protein binding competition. Use Caution/Monitor. Due to high protein binding capacity of both drugs, one may displace the other when coadministered leading to an enhanced effect of the displaced drug; risk is low with low dose aspirin.
- sulfasalazine
aspirin and sulfasalazine both increase anticoagulation. Use Caution/Monitor.
aspirin and sulfasalazine both increase serum potassium. Use Caution/Monitor. - sulindac
aspirin and sulindac both increase anticoagulation. Use Caution/Monitor.
aspirin and sulindac both increase serum potassium. Use Caution/Monitor. - tafluprost
tafluprost, aspirin. unspecified interaction mechanism. Use Caution/Monitor. There are conflicting reports from studies of either increased or decreased IOP when ophthalmic prostaglandins are coadministered with NSAIDs (either systemic or ophthalmic).
- tamoxifen
diphenhydramine decreases effects of tamoxifen by decreasing metabolism. Use Caution/Monitor. Inhibition of CYP2D6 metabolism to tamoxifen's active metabolite, endoxifen.
- tamsulosin
diphenhydramine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- tapentadol
diphenhydramine and tapentadol both increase sedation. Use Caution/Monitor.
- tazemetostat
acetaminophen will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- telmisartan
telmisartan and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of telmisartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect.
telmisartan, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals. - temazepam
diphenhydramine and temazepam both increase sedation. Use Caution/Monitor.
- temocillin
temocillin, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
temocillin, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor. - tenecteplase
aspirin, tenecteplase. Either increases toxicity of the other by anticoagulation. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- terazosin
aspirin decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- terbutaline
diphenhydramine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
aspirin increases and terbutaline decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - tetracaine
tetracaine, acetaminophen. Other (see comment). Use Caution/Monitor. Comment: Monitor for signs of methemoglobinemia when methemoglobin-inducing drugs are coadministered.
- thioridazine
diphenhydramine and thioridazine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.
thioridazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - ticagrelor
aspirin, ticagrelor. Other (see comment). Use Caution/Monitor. Comment: Maintenance doses of aspirin above 100 mg decreases effectiveness of ticagrelor. Therefore, after the initial loading dose of aspirin (usually 325 mg), use ticagrelor with a maintenance dose of aspirin of 75-100 mg.
- thiothixene
diphenhydramine and thiothixene both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of thiothixene by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of thiothixene by pharmacodynamic antagonism. Use Caution/Monitor.
thiothixene increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - ticarcillin
ticarcillin, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.
ticarcillin, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor. - timolol
timolol and aspirin both increase serum potassium. Use Caution/Monitor.
diphenhydramine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
aspirin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. - tinidazole
acetaminophen will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tiotropium
diphenhydramine and tiotropium both decrease cholinergic effects/transmission. Use Caution/Monitor.
- tirofiban
aspirin, tirofiban. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. The need for simultaneous use of low-dose aspirin and anticoagulant or antiplatelet agents are common for patients with cardiovascular disease; monitor closely.
- tobramycin inhaled
tobramycin inhaled and aspirin both increase nephrotoxicity and/or ototoxicity. Modify Therapy/Monitor Closely. Avoid concurrent or sequential use to decrease risk for ototoxicity
- tolazamide
aspirin increases effects of tolazamide by unknown mechanism. Use Caution/Monitor. Risk of hypoglycemia.
- tolbutamide
aspirin increases effects of tolbutamide by unknown mechanism. Use Caution/Monitor. Risk of hypoglycemia.
- tolfenamic acid
aspirin and tolfenamic acid both increase anticoagulation. Use Caution/Monitor.
aspirin and tolfenamic acid both increase serum potassium. Use Caution/Monitor. - tolmetin
aspirin and tolmetin both increase anticoagulation. Use Caution/Monitor.
aspirin and tolmetin both increase serum potassium. Use Caution/Monitor. - tolterodine
diphenhydramine and tolterodine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- tolvaptan
aspirin and tolvaptan both increase serum potassium. Use Caution/Monitor.
- topiramate
diphenhydramine and topiramate both increase sedation. Modify Therapy/Monitor Closely.
- torsemide
aspirin increases and torsemide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- tramadol
diphenhydramine decreases effects of tramadol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Decreased conversion of tramadol to active metabolite.
diphenhydramine and tramadol both increase sedation. Use Caution/Monitor.
diphenhydramine decreases effects of tramadol by decreasing metabolism. Use Caution/Monitor. Decreased conversion of tramadol to active metabolite. - trandolapril
trandolapril, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly with high dose aspirin, in elderly and volume depleted.
- travoprost ophthalmic
travoprost ophthalmic, aspirin. unspecified interaction mechanism. Use Caution/Monitor. There are conflicting reports from studies of either increased or decreased IOP when ophthalmic prostaglandins are coadministered with NSAIDs (either systemic or ophthalmic).
- trazodone
diphenhydramine and trazodone both increase sedation. Use Caution/Monitor.
trazodone, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets. - triamcinolone acetonide injectable suspension
aspirin, triamcinolone acetonide injectable suspension. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Aspirin in conjunction with corticosteroids in hypoprothrombinemia should used with caution. Clearance of salicylates may increase with concurrent use of corticosteroids.
- triazolam
diphenhydramine and triazolam both increase sedation. Use Caution/Monitor.
- triamterene
triamterene and aspirin both increase serum potassium. Modify Therapy/Monitor Closely.
- triclofos
diphenhydramine and triclofos both increase sedation. Use Caution/Monitor.
- trifluoperazine
diphenhydramine and trifluoperazine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
trifluoperazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - trihexyphenidyl
diphenhydramine and trihexyphenidyl both decrease cholinergic effects/transmission. Use Caution/Monitor. Potential for additive anticholinergic effects.
- trimipramine
diphenhydramine and trimipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and trimipramine both increase sedation. Use Caution/Monitor. - triprolidine
diphenhydramine and triprolidine both increase sedation. Use Caution/Monitor.
- trospium chloride
diphenhydramine and trospium chloride both decrease cholinergic effects/transmission. Use Caution/Monitor.
- valerian
valerian increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- valproic acid
aspirin increases levels of valproic acid by plasma protein binding competition. Use Caution/Monitor.
- valsartan
valsartan and aspirin both increase serum potassium. Use Caution/Monitor.
aspirin decreases effects of valsartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect.
valsartan, aspirin. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals. - vecuronium
diphenhydramine and vecuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.
- venlafaxine
venlafaxine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.
- voclosporin
voclosporin, aspirin. Either increases toxicity of the other by nephrotoxicity and/or ototoxicity. Modify Therapy/Monitor Closely. Coadministration with drugs associated with nephrotoxicity may increase the risk for acute and/or chronic nephrotoxicity.
- vorapaxar
aspirin, vorapaxar. Either increases effects of the other by anticoagulation. Use Caution/Monitor. Coadministration of anticoagulants, antiplatelets, or other drug affecting coagulation should be monitored periodically due to potential increased risk of bleeding.
aspirin, vorapaxar. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive antiplatelet effect may occur. - vortioxetine
aspirin, vortioxetine. Either increases effects of the other by anticoagulation. Use Caution/Monitor. Risk minimal with low-dose aspirin.
- warfarin
aspirin increases effects of warfarin by anticoagulation. Modify Therapy/Monitor Closely. Avoid coadministration of chronic high-dose aspirin. Aspirin's antiplatelet properties may increase anticoagulation effect of warfarin. The need for simultaneous use of low-dose aspirin and warfarin is common for patients with cardiovascular disease. .
acetaminophen increases effects of warfarin by anticoagulation. Use Caution/Monitor. - xylometazoline
diphenhydramine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- yohimbine
diphenhydramine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- zanubrutinib
aspirin, zanubrutinib. Either increases effects of the other by anticoagulation. Modify Therapy/Monitor Closely. Zanubrutinib-induced cytopenias increases risk of hemorrhage. Coadministration of zanubritinib with antiplatelets or anticoagulants may further increase this risk.
- ziconotide
diphenhydramine and ziconotide both increase sedation. Use Caution/Monitor.
- ziprasidone
diphenhydramine and ziprasidone both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of ziprasidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine decreases levels of ziprasidone by pharmacodynamic antagonism. Use Caution/Monitor.
ziprasidone increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. - zotepine
aspirin decreases effects of zotepine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
diphenhydramine decreases levels of zotepine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
diphenhydramine and zotepine both increase sedation. Use Caution/Monitor.
diphenhydramine decreases levels of zotepine by pharmacodynamic antagonism. Use Caution/Monitor.
Minor (195)
- aceclofenac
aceclofenac will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- acemetacin
acemetacin will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- acetazolamide
acetazolamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
aspirin will decrease the level or effect of acetazolamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. - acyclovir
aspirin will increase the level or effect of acyclovir by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- albiglutide
albiglutide decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.
- alendronate
aspirin, alendronate. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of GI ulceration.
- aluminum hydroxide
aluminum hydroxide, aspirin. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).
- amikacin
aspirin increases levels of amikacin by decreasing renal clearance. Minor/Significance Unknown. Interaction mainly occurs in preterm infants.
- aminohippurate sodium
aspirin will increase the level or effect of aminohippurate sodium by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- anamu
aspirin and anamu both increase anticoagulation. Minor/Significance Unknown.
- anastrozole
aspirin will decrease the level or effect of anastrozole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- antithrombin alfa
acetaminophen increases effects of antithrombin alfa by unknown mechanism. Minor/Significance Unknown.
- antithrombin III
acetaminophen increases effects of antithrombin III by unknown mechanism. Minor/Significance Unknown.
- argatroban
acetaminophen increases effects of argatroban by unknown mechanism. Minor/Significance Unknown.
- aripiprazole
diphenhydramine will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- ascorbic acid
ascorbic acid will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
aspirin decreases levels of ascorbic acid by increasing renal clearance. Minor/Significance Unknown.
ascorbic acid increases levels of aspirin by decreasing renal clearance. Minor/Significance Unknown. - ashwagandha
ashwagandha increases effects of diphenhydramine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.
- balsalazide
aspirin will increase the level or effect of balsalazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- bemiparin
acetaminophen increases effects of bemiparin by unknown mechanism. Minor/Significance Unknown.
- bendroflumethiazide
bendroflumethiazide will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- bismuth subsalicylate
bismuth subsalicylate increases effects of aspirin by pharmacodynamic synergism. Minor/Significance Unknown.
- bivalirudin
acetaminophen increases effects of bivalirudin by unknown mechanism. Minor/Significance Unknown.
- brimonidine
brimonidine increases effects of diphenhydramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.
- bumetanide
aspirin, bumetanide. Other (see comment). Minor/Significance Unknown. Comment: Salicylates are less likely than other NSAIDs to interact w/bumetanide.
- calcium carbonate
calcium carbonate, aspirin. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).
- carbamazepine
carbamazepine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- cefadroxil
cefadroxil will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- cefamandole
cefamandole will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- cefepime
cefepime will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- cefixime
cefixime will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- cefpirome
cefpirome will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- cefprozil
cefprozil will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- ceftazidime
ceftazidime will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- ceftibuten
ceftibuten will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- celecoxib
aspirin will increase the level or effect of celecoxib by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- cephalexin
cephalexin will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- ceritinib
aspirin will decrease the level or effect of ceritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- chlorothiazide
chlorothiazide will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- chlorpromazine
diphenhydramine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- chlorpropamide
aspirin will increase the level or effect of chlorpropamide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
aspirin increases effects of chlorpropamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate. - chlorthalidone
chlorthalidone will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- cholestyramine
cholestyramine decreases levels of acetaminophen by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- choline magnesium trisalicylate
aspirin will increase the level or effect of choline magnesium trisalicylate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- chromium
aspirin increases levels of chromium by unspecified interaction mechanism. Minor/Significance Unknown.
- clonazepam
clonazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- colestipol
colestipol decreases levels of acetaminophen by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- cortisone
cortisone decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- creatine
creatine, aspirin. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. (Theoretical interaction) Combination may have additive nephrotoxic effects.
- cyanocobalamin
aspirin decreases levels of cyanocobalamin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- cyclopenthiazide
cyclopenthiazide will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- cyclophosphamide
aspirin will decrease the level or effect of cyclophosphamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- dalteparin
acetaminophen increases effects of dalteparin by unknown mechanism. Minor/Significance Unknown.
- danshen
aspirin and danshen both increase anticoagulation. Minor/Significance Unknown.
- deflazacort
deflazacort decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- desipramine
diphenhydramine and desipramine both decrease cholinergic effects/transmission. Minor/Significance Unknown.
desipramine and diphenhydramine both decrease cholinergic effects/transmission. Minor/Significance Unknown. - devil's claw
aspirin and devil's claw both increase anticoagulation. Minor/Significance Unknown.
- dexamethasone
dexamethasone decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- dexfenfluramine
diphenhydramine will increase the level or effect of dexfenfluramine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- dextroamphetamine
diphenhydramine will increase the level or effect of dextroamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- dextromethorphan
diphenhydramine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- diazepam
diazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- diclofenac
aspirin will increase the level or effect of diclofenac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- diclofenac topical
diclofenac topical, aspirin. Either increases effects of the other by pharmacodynamic synergism. Minor/Significance Unknown. Although low, there is systemic exposure to diclofenac topical; theoretically, concomitant administration with systemic NSAIDS or aspirin may result in increased NSAID adverse effects.
- diflunisal
aspirin will increase the level or effect of diflunisal by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- diltiazem
diltiazem increases effects of aspirin by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.
- dimenhydrinate
dimenhydrinate increases toxicity of diphenhydramine by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.
- disulfiram
disulfiram will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Minor/Significance Unknown.
- donepezil
diphenhydramine will increase the level or effect of donepezil by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
donepezil decreases effects of diphenhydramine by pharmacodynamic antagonism. Minor/Significance Unknown. - doxepin
diphenhydramine will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- encainide
diphenhydramine will increase the level or effect of encainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- enoxaparin
acetaminophen increases effects of enoxaparin by unknown mechanism. Minor/Significance Unknown.
- eplerenone
aspirin decreases effects of eplerenone by pharmacodynamic antagonism. Minor/Significance Unknown. NSAIDs decrease prostaglandin synthesis.
- ethanol
ethanol will decrease the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Minor/Significance Unknown.
ethanol increases toxicity of acetaminophen by decreasing metabolism. Minor/Significance Unknown.
ethanol increases toxicity of aspirin by pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of GI bleeding. - ethosuximide
ethosuximide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- etodolac
aspirin will increase the level or effect of etodolac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- eucalyptus
diphenhydramine and eucalyptus both increase sedation. Minor/Significance Unknown.
- felbamate
felbamate decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- fenbufen
aspirin will increase the level or effect of fenbufen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- fenoprofen
aspirin will increase the level or effect of fenoprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- fesoterodine
diphenhydramine will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- feverfew
aspirin decreases effects of feverfew by pharmacodynamic antagonism. Minor/Significance Unknown.
- fludrocortisone
fludrocortisone decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- fluoxetine
diphenhydramine will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- fluphenazine
diphenhydramine will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- flurbiprofen
aspirin will increase the level or effect of flurbiprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- folic acid
aspirin decreases levels of folic acid by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- fondaparinux
acetaminophen increases effects of fondaparinux by unknown mechanism. Minor/Significance Unknown.
- fosphenytoin
fosphenytoin decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- furosemide
aspirin decreases effects of furosemide by pharmacodynamic antagonism. Minor/Significance Unknown. NSAIDs decrease prostaglandin synthesis.
- galantamine
diphenhydramine will increase the level or effect of galantamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
galantamine decreases effects of diphenhydramine by pharmacodynamic antagonism. Minor/Significance Unknown. - ganciclovir
aspirin will increase the level or effect of ganciclovir by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- gentamicin
aspirin increases levels of gentamicin by decreasing renal clearance. Minor/Significance Unknown. Interaction mainly occurs in preterm infants.
- glimepiride
aspirin increases effects of glimepiride by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.
- glipizide
aspirin increases effects of glipizide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.
- glyburide
aspirin increases effects of glyburide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.
- green tea
green tea increases effects of acetaminophen by pharmacodynamic synergism. Minor/Significance Unknown. (Theoretical, due to caffeine content).
- heparin
acetaminophen increases effects of heparin by unknown mechanism. Minor/Significance Unknown.
- hydrochlorothiazide
hydrochlorothiazide will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- hydrocortisone
hydrocortisone decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- ibuprofen
aspirin will increase the level or effect of ibuprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- imidapril
aspirin decreases effects of imidapril by pharmacodynamic antagonism. Minor/Significance Unknown. NSAIDs decrease prostaglandin synthesis.
- indapamide
indapamide will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- indomethacin
aspirin will increase the level or effect of indomethacin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- isoniazid
isoniazid increases toxicity of acetaminophen by unknown mechanism. Minor/Significance Unknown.
- ketoprofen
aspirin will increase the level or effect of ketoprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- ketorolac
aspirin will increase the level or effect of ketorolac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- ketorolac intranasal
aspirin will increase the level or effect of ketorolac intranasal by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- L-methylfolate
aspirin decreases levels of L-methylfolate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- lacosamide
lacosamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- lamotrigine
lamotrigine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- larotrectinib
aspirin will decrease the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- levetiracetam
levetiracetam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- levoketoconazole
aspirin will decrease the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- liraglutide
liraglutide decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.
- loratadine
diphenhydramine will increase the level or effect of loratadine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- lorazepam
lorazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- lornoxicam
aspirin will increase the level or effect of lornoxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- meclofenamate
aspirin will increase the level or effect of meclofenamate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- mefenamic acid
aspirin will increase the level or effect of mefenamic acid by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- meloxicam
aspirin will increase the level or effect of meloxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- mesalamine
aspirin will increase the level or effect of mesalamine by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- methsuximide
methsuximide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- methyclothiazide
methyclothiazide will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- methylprednisolone
methylprednisolone decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- metoclopramide
metoclopramide increases levels of acetaminophen by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- metolazone
metolazone will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- metronidazole
metronidazole will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Minor/Significance Unknown.
- nabumetone
aspirin will increase the level or effect of nabumetone by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- naproxen
aspirin will increase the level or effect of naproxen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- neomycin PO
aspirin increases levels of neomycin PO by decreasing renal clearance. Minor/Significance Unknown. Interaction mainly occurs in preterm infants.
- nettle
nettle increases effects of diphenhydramine by pharmacodynamic synergism. Minor/Significance Unknown. (High dose nettle; theoretical interaction) May enhance CNS depression.
- nitazoxanide
nitazoxanide, diphenhydramine. Either increases levels of the other by Mechanism: plasma protein binding competition. Minor/Significance Unknown.
- noni juice
aspirin and noni juice both increase serum potassium. Minor/Significance Unknown.
- ofloxacin
ofloxacin, aspirin. Other (see comment). Minor/Significance Unknown. Comment: Risk of CNS stimulation/seizure. Mechanism: Displacement of GABA from receptors in brain.
- oxaprozin
aspirin will increase the level or effect of oxaprozin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- oxcarbazepine
oxcarbazepine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- oxybutynin
oxybutynin decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.
- oxybutynin topical
oxybutynin topical decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.
- oxybutynin transdermal
oxybutynin transdermal decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.
- oxycodone
diphenhydramine decreases effects of oxycodone by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of oxycodone to active metabolite morphine.
- parecoxib
aspirin will increase the level or effect of parecoxib by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- paromomycin
aspirin increases levels of paromomycin by decreasing renal clearance. Minor/Significance Unknown. Interaction mainly occurs in preterm infants.
- paroxetine
diphenhydramine will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- penicillin VK
penicillin VK, aspirin. Either increases levels of the other by decreasing renal clearance. Minor/Significance Unknown.
- pentazocine
aspirin, pentazocine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Possible risk of renal papillary necrosis w/chronic Tx.
- perhexiline
diphenhydramine will increase the level or effect of perhexiline by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- perphenazine
diphenhydramine will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- phenindione
acetaminophen increases effects of phenindione by unknown mechanism. Minor/Significance Unknown.
- phenobarbital
phenobarbital decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- phenytoin
phenytoin decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- piperacillin
piperacillin, aspirin. Either increases effects of the other by receptor binding competition. Minor/Significance Unknown. Salicylic acid could be displaced from protein binding sites or it could itself displace other protein-bound drugs and result in an enhanced effect of the displaced drug.
- piroxicam
aspirin will increase the level or effect of piroxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- prednisolone
prednisolone decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- prednisone
prednisone decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- primidone
primidone decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- prochlorperazine
diphenhydramine will increase the level or effect of prochlorperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- promazine
diphenhydramine will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- promethazine
diphenhydramine will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- protamine
acetaminophen increases effects of protamine by unknown mechanism. Minor/Significance Unknown.
- rifabutin
rifabutin decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- rifampin
rifampin decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- risperidone
diphenhydramine will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- rose hips
rose hips will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
aspirin decreases levels of rose hips by increasing renal clearance. Minor/Significance Unknown.
rose hips increases levels of aspirin by decreasing renal clearance. Minor/Significance Unknown. - rufinamide
rufinamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- ruxolitinib
acetaminophen will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ruxolitinib topical
acetaminophen will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sage
diphenhydramine and sage both increase sedation. Minor/Significance Unknown.
- Siberian ginseng
Siberian ginseng increases effects of diphenhydramine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.
- salicylates (non-asa)
aspirin will increase the level or effect of salicylates (non-asa) by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- salsalate
aspirin will increase the level or effect of salsalate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- sodium bicarbonate
sodium bicarbonate, aspirin. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).
- sodium citrate/citric acid
sodium citrate/citric acid, aspirin. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).
- stiripentol
aspirin will decrease the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- streptomycin
aspirin increases levels of streptomycin by decreasing renal clearance. Minor/Significance Unknown. Interaction mainly occurs in preterm infants.
- sulfadiazine
aspirin increases levels of sulfadiazine by unspecified interaction mechanism. Minor/Significance Unknown.
- sulfasalazine
aspirin will increase the level or effect of sulfasalazine by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- sulfisoxazole
aspirin increases levels of sulfisoxazole by unspecified interaction mechanism. Minor/Significance Unknown.
- sulindac
aspirin will increase the level or effect of sulindac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- teniposide
aspirin increases levels of teniposide by unspecified interaction mechanism. Minor/Significance Unknown.
- tiagabine
tiagabine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- tiludronate
aspirin decreases levels of tiludronate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- tobramycin
aspirin increases levels of tobramycin by decreasing renal clearance. Minor/Significance Unknown. Interaction mainly occurs in preterm infants.
- tolazamide
aspirin increases effects of tolazamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.
- tolbutamide
aspirin increases effects of tolbutamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.
- tolfenamic acid
aspirin will increase the level or effect of tolfenamic acid by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- tolmetin
aspirin will increase the level or effect of tolmetin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- tolterodine
diphenhydramine will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- topiramate
topiramate decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- trazodone
diphenhydramine and trazodone both decrease cholinergic effects/transmission. Minor/Significance Unknown.
- triamcinolone acetonide injectable suspension
triamcinolone acetonide injectable suspension decreases levels of aspirin by increasing renal clearance. Minor/Significance Unknown.
- triamterene
triamterene, aspirin. Other (see comment). Minor/Significance Unknown. Comment: Risk of acute renal failure. Mechanism: NSAIDs decrease prostaglandin synthesis, which normally protect against nephrotoxicity.
aspirin increases toxicity of triamterene by pharmacodynamic antagonism. Minor/Significance Unknown. NSAIDs decrease prostaglandin synthesis, increasing the risk of nephrotoxicity. - trifluoperazine
diphenhydramine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- tropisetron
diphenhydramine will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- valganciclovir
aspirin will increase the level or effect of valganciclovir by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- valproic acid
valproic acid decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
Adverse Effects
Frequency Not Defined (Acetaminophen)
Angioedema, laryngeal edema
Pruritic maculopapular rash, urticaria
Agranulocytosis, leukopenia, neutropenia, pancytopenia, thrombocytopenia, thrombocytopenic purpura
Hepatotoxicity
May increase uric acid, chloride, glucose
May decrease sodium, calcium, bicarbonate
Anaphylactoid reaction
Frequency Not Defined (Aspirin)
Rash, urticaria
Dyspepsia, heartburn, nausea, stomach pain, vomiting
Tinnitus (high or chronic dose)
Frequency Not Defined (Diphenhydramine)
Sedation
Confusion
May decrease cognitive function in geriatric patients
Anticholinergic effects
Blurred vision
Diplopia
Xerostomia
Dry nasal mucosa
Pharyngeal dryness
Thick bronchial sputum
Constipation
Urinary retention
Agranulocytosis
Hemolytic anemia
Thrombocytopenia
Convulsions
Tachycardia
Palpitations
Hypotension
Nervousness
Restlessness
Euphoria
Vertigo
Menstrual irregularities
Anorexia
Neuritis
Tinnitus
Warnings
Contraindications
Allergy to acetaminophen, aspirin, or diphenhydramine products
Coadministration with other acetaminophen containing medications; increased risk for severe hepatic impairment
Coadministration with other diphenhydramine containing products (even topical diphenhydramine)
Cautions
Acetaminophen
- Hepatic impairment or consumption of 3 or more alcoholic beverages/day may increase risk for liver damage (associated with acetaminophen)
- Do not take with other products that contain acetaminophen due to risk of additive toxicity/overdose
- Risk for rare, but serious skin reactions that can be fatal; these reactions include Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP); symptoms may include skin redness, blisters and rash
Aspirin
- Children and adolescents should not use aspirin for symptoms of viral infections (eg, chickenpox, influenza) due to risk for Reye syndrome
- Risk for GI bleeding
- Avoid with active peptic ulcer disease
- Avoid in severe renal impairment (ie, CrCl <10 mL/min)
Diphenhydramine
- May cause CNS depression, which can impair driving or operating heavy machinery
- May potentiate effects of sedatives such as alcohol
- Use caution in patients with angle-closure glaucoma, prostatic hypertrophy, stenosing peptic ulcer, pyloroduodenal obstruction, thyroid dysfunction
- Elderly patients: Considered high-risk medication for this age group because it may increase risk of falls and has high incidence of anticholinergic effects; may exacerbate existing lower urinary tract conditions or benign prostatic hyperplasia; use in special situations may be appropriate; not recommended for treatment of insomnia, because tolerance develops and risk of anticholinergic effects increases
Pregnancy & Lactation
Pregnancy
Avoid aspirin (NSAIDs) during pregnancy, particularly in third trimester because of risk for premature closure of the ductus arteriosus
Lactation
Information below is from LactMed (a TOXNET database)
Aspirin
- Excreted in human breast milk as the salicylate metabolite
- Avoid high-dose during lactation; may take low-dose aspirin (ie, 75-162 mg/day) and avoid breastfeeding for 1-2 hr after dose to minimize antiplatelet effects on infant
Acetaminophen
- Excreted in low levels in human breast milk; amount in milk is much less than doses usually given to infants
Diphenhydramine
- No studies using modern assay methods to detect drug levels in breast milk have been reported
- Small, occasional doses of diphenhydramine would not be expected to cause any adverse effects in breastfed infants
- Larger doses or more prolonged use may cause effects in the infant or decrease the milk supply
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Acetaminophen: Inhibits prostaglandin synthesis in CNS and may block peripheral pain impulse generation; acts on hypothalamus as antipyretic
Aspirin: Acts on hypothalamus to produce antipyresis; anti-inflammatory properties attributed to prostaglandin synthetase inhibition resulting in decreased formation of thromboxane A2
Diphenhydramine: Histamine H1-receptor antagonist with sedative properties
Administration
Instructions
Swallow caplet with full glass of water
Storage
Store at room temperature (20-25°C [68-77°F])
Close bottle cap tightly after use