Dosing & Uses
Dosage Forms & Strengths
acetaminophen/dextromethorphan
liquid
- (1000mg/30mg)/30mL
- (160mg/5mg)/5mL
Relief of Cold & Flu Symptoms
30mL [(1000mg/30mg)/30mL] PO q6hr; not to exceed 120 mL/day
Dosage Forms & Strengths
acetaminophen/dextromethorphan
liquid
- (1000mg/30mg)/30mL
- (160mg/5mg)/5mL
Relief of Cold & Flu Symptoms
4 Years Old
- Not recommended
4-6 Years Old
- 5mL [(160mg/5mg)/5mL] PO q4hr; not to exceed 5 doses/day
6-12 Years Old
- 10mL [(160mg/5mg)/5mL] PO q4hr; not to exceed 5 doses/day
>12 Years Old
- 30mL [(1000mg/30mg)/30mL] PO q6hr; not to exceed 120mL/day
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (3)
- 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.
- 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.
- 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.
Monitor Closely (26)
- 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.
- atogepant
acetaminophen will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- avapritinib
acetaminophen will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- axitinib
acetaminophen increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- 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.
- 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.
- dapsone topical
acetaminophen increases toxicity of dapsone topical by altering metabolism. Modify Therapy/Monitor Closely. May induce methemoglobinemia .
- eltrombopag
eltrombopag increases levels of acetaminophen by decreasing metabolism. Use Caution/Monitor. UGT inhibition; significance of interaction unclear.
- 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.
- 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.
- flibanserin
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.
- 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.
- 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.
- ivacaftor
acetaminophen increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .
- 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.
- 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. - 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.
- lomitapide
acetaminophen increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.
- 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.
- 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.
- tazemetostat
acetaminophen will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tetracaine
tetracaine, acetaminophen. Other (see comment). Use Caution/Monitor. Comment: Monitor for signs of methemoglobinemia when methemoglobin-inducing drugs are coadministered.
- tinidazole
acetaminophen will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- warfarin
acetaminophen increases effects of warfarin by anticoagulation. Use Caution/Monitor.
Minor (49)
- acetazolamide
acetazolamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- albiglutide
albiglutide decreases levels of acetaminophen by unspecified interaction mechanism. 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.
- bemiparin
acetaminophen increases effects of bemiparin by unknown mechanism. Minor/Significance Unknown.
- bivalirudin
acetaminophen increases effects of bivalirudin by unknown mechanism. Minor/Significance Unknown.
- carbamazepine
carbamazepine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- cholestyramine
cholestyramine decreases levels of acetaminophen by inhibition of GI absorption. Applies only to oral form of both agents. 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.
- dalteparin
acetaminophen increases effects of dalteparin by unknown mechanism. Minor/Significance Unknown.
- diazepam
diazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- disulfiram
disulfiram will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Minor/Significance Unknown.
- enoxaparin
acetaminophen increases effects of enoxaparin by unknown mechanism. Minor/Significance Unknown.
- 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. - ethosuximide
ethosuximide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- felbamate
felbamate decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- 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.
- 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.
- isoniazid
isoniazid increases toxicity of acetaminophen by unknown mechanism. 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.
- levetiracetam
levetiracetam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- liraglutide
liraglutide decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.
- lorazepam
lorazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- methsuximide
methsuximide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- metoclopramide
metoclopramide increases levels of acetaminophen by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- metronidazole
metronidazole will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. 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.
- 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.
- primidone
primidone decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- 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.
- 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.
- tiagabine
tiagabine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- topiramate
topiramate decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- valproic acid
valproic acid decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.
- zonisamide
zonisamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism increase levels of hepatotoxic metabolites.
Frequency Not Defined
Dizziness
Drowsiness
Dermatologic rash
GI disturbances
Anemia blood dyscrasias (neutropenia, pancytopenia, leukopenia)
Bilirubin and alkaline phosphatase may increase
Warnings
Contraindications
Contraindicated in documented hypersensitivity; asthma attacks, narrow-angle glaucoma, symptomatic prostate hypertrophy, bladder-neck obstruction, and stenosing peptic ulcer; known G-6-PD deficiency
Acetaminophen hepatotoxicity possible in chronic alcoholics following various dose levels; severe or recurrent pain or high or continued fever may indicate a serious illness; contained in many OTC products and combined use with these products may result in toxicity due to cumulative doses exceeding recommended maximum dose
Do not take dextromethorphan for persistent or chronic cough associated with smoking, asthma, or emphysema, or if it is accompanied by excessive phlegm unless directed by a healthcare provider; dextromethorphan may slow the breathing
Cautions
Acetaminophen: 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
Pregnancy & Lactation
Pregnant or breastfeeding patients should seek advice of health professional before using OTC drugs
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 blocks pain impulse generation peripherally and may inhibit the generation of prostaglandin in the CNS. Reduces fever by inhibiting the hypothalamic heat-regulating center.
Dextromethorphan is a cough suppressant that acts centrally on the cough center in the medulla.
Pharmacokinetics
Acetaminophen
- Peak plasma time: 10-60 min (PO immediate release); 60-120 min (PO extended release); 6 hr (PO 500 mg tablet); 8 hr (PO 650 mg extended release tablet)
- Vd: 1 L/kg
- Protein binding: 10-25%
- Metabolism: Liver (microsomal enzyme systems); conjugation (glucuronic acid)
- Half-life: 1.25-3hr
- Excretion: Urine
Dextromethorphan
- Onset: 15-30 min
- Duration: 3-6 hr
- Metabolism: Hepatic P450 enzyme CYP2D6
- Excretion: Urine
- Half-life: 2-4 hr (extensive metabolizers); 24 hr (poor metabolizers)
- Peak plasma time: 2-3 hr
