butalbital/acetaminophen (Rx)

Brand and Other Names:Phrenilin Forte, Phrenilin, more...Bupap, Orbivan CF
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Dosing & Uses

AdultPediatricGeriatric

Dosage Forms & Strengths

FDA is asking manufacturers to limit acetaminophen in prescription products to 325 mg/dosage unit; manufacturers have until January 14, 2014 to comply

butalbital/acetaminophen

tablet

  • 50mg/300mg (Orbivan CF)
  • 50mg/325mg (Phrenilin)
  • 50mg/650mg (Bupap)

capsule

  • 50mg/650mg (Phrenilin Forte)

Tension Headache

1-2 tab/cap PO q4hr; not to exceed 6 tab/cap per day

Not to exceed 4 g acetaminophen/24 hr

Renal Impairment

Mild-to-moderate: Administer lower dose

Severe: Use caution

Hepatic Impairment

Mild-to-moderate: Administer lower dose

Severe: Use caution

Dosage Forms & Strengths

FDA is asking manufacturers to limit acetaminophen in prescription products to 325 mg/dosage unit; manufacturers have until January 14, 2014 to comply

butalbital/acetaminophen

tablet

  • 50mg/300mg (Orbivan CF)
  • 50mg/325mg (Phrenilin)
  • 50mg/650mg (Bupap)

capsule

  • 50mg/650mg (Phrenilin Forte)

Tension Headache

<12 years: Safety and efficacy not established

≥12 years: As adults; 1-2 tab or cap PO q4hr; not to exceed 6 tab or cap per day

Not to exceed 4 g acetaminophen/24 hr

Tension headache

1-2 tab/cap PO q4hr; not to exceed 6 tab/cap per day

Not to exceed 4 g acetaminophen/24 hr

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Interactions

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and butalbital/acetaminophen

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            Contraindicated (6)

            • doravirine

              butalbital will decrease the level or effect of doravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of doravirine with a strong CYP3A inducer may decrease doravirine plasma concentrations and/or effects. Potential for loss of virologic response and possible resistance to doravirine.

            • fostemsavir

              butalbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.

            • isavuconazonium sulfate

              butalbital will decrease the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • lonafarnib

              butalbital will decrease the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lonafarnib is a sensitive CYP3A4 substrate. Coadministration with strong or moderate CYP3A4 inducers is contraindicated.

            • lorlatinib

              butalbital will decrease the level or effect of lorlatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of lorlatinib with strong CYP3A inducers is contraindicated. Discontinue the strong CYP3A inducer for 3 plasma half-lives before initiating lorlatinib.

            • mavacamten

              butalbital will decrease the level or effect of mavacamten by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            Serious - Use Alternative (71)

            • abemaciclib

              butalbital will decrease the level or effect of abemaciclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of abemaciclib with strong CYP3A4 inducers reduces plasma concentration of abemaciclib and its metabolites.

            • alosetron

              butalbital will decrease the level or effect of alosetron by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

            • alpelisib

              butalbital will decrease the level or effect of alpelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of alpelisib (CYP3A4 substrate) with strong CYP3A4 inducers.

            • antithrombin alfa

              butalbital decreases effects of antithrombin alfa by increasing metabolism. Avoid or Use Alternate Drug.

            • antithrombin III

              butalbital decreases effects of antithrombin III by increasing metabolism. Avoid or Use Alternate Drug.

            • argatroban

              butalbital decreases effects of argatroban by increasing metabolism. Avoid or Use Alternate Drug.

            • avapritinib

              butalbital will decrease the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • bemiparin

              butalbital decreases effects of bemiparin by increasing metabolism. Avoid or Use Alternate Drug.

            • benzhydrocodone/acetaminophen

              benzhydrocodone/acetaminophen, butalbital. Either increases toxicity 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.

            • bivalirudin

              butalbital decreases effects of bivalirudin by increasing metabolism. Avoid or Use Alternate Drug.

            • brigatinib

              butalbital will decrease the level or effect of brigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong CYP3A4 inducers may decrease brigatinib efficacy.

            • calcium/magnesium/potassium/sodium oxybates

              butalbital, 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.

            • copanlisib

              butalbital will decrease the level or effect of copanlisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of copanlisib with strong CYP3A4 inducers.

            • dalteparin

              butalbital decreases effects of dalteparin by increasing metabolism. Avoid or Use Alternate Drug.

            • daridorexant

              butalbital will decrease the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • deflazacort

              butalbital will decrease the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of deflazacort with moderate or strong CYP3A4 inducers.

            • dihydroergotamine

              butalbital will decrease the level or effect of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • dihydroergotamine intranasal

              butalbital will decrease the level or effect of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • dipyridamole

              butalbital decreases levels of dipyridamole by increasing metabolism. Contraindicated.

            • dronedarone

              butalbital will decrease the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • duloxetine

              butalbital will decrease the level or effect of duloxetine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

            • duvelisib

              butalbital will increase the level or effect of duvelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with a strong CYP3A inducer decreases duvelisib area under the curve (AUC), which may reduce duvelisib efficacy.

            • elacestrant

              butalbital will decrease the level or effect of elacestrant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • enoxaparin

              butalbital decreases effects of enoxaparin by increasing metabolism. Avoid or Use Alternate Drug.

            • erdafitinib

              butalbital will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ergotamine

              butalbital will decrease the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin base

              butalbital will decrease the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin ethylsuccinate

              butalbital will decrease the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin lactobionate

              butalbital will decrease the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin stearate

              butalbital will decrease the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • everolimus

              butalbital will decrease the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • fedratinib

              butalbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

            • fentanyl

              fentanyl, butalbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

            • fentanyl intranasal

              fentanyl intranasal, butalbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

            • fentanyl transdermal

              fentanyl transdermal, butalbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

            • fentanyl transmucosal

              fentanyl transmucosal, butalbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

            • fexinidazole

              butalbital will increase the level or effect of fexinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP450 inducers may significantly increase plasma concentrations of fexinidazole?s active metabolites: fexinidazole sulfoxide (M1) and fexinidazole sulfone (M2). M2 plasma concentrations associated with increased QT prolongation risks.

            • finerenone

              butalbital will decrease the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • fondaparinux

              butalbital decreases effects of fondaparinux by increasing metabolism. Avoid or Use Alternate Drug.

            • fostamatinib

              butalbital will decrease the level or effect of fostamatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ganaxolone

              butalbital will decrease the level or effect of ganaxolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of ganaxolone with moderate or strong CYP3A4 inducers. If coadministration unavoidable, consider increasing ganaxolone dose; however, do not exceed maximum daily dose for weight.

            • glasdegib

              butalbital will decrease the level or effect of glasdegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of glasdegib with strong CYP3A inducers.

            • heparin

              butalbital decreases effects of heparin by increasing metabolism. Avoid or Use Alternate Drug.

            • hydrocodone

              hydrocodone, butalbital. Either increases toxicity 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.

            • infigratinib

              butalbital will decrease the level or effect of infigratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • isocarboxazid

              isocarboxazid, butalbital. Other (see comment). Contraindicated. Comment: CNS depressants such as barbiturates should not be used in combination with isocarboxazid.

            • istradefylline

              butalbital will decrease the level or effect of istradefylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of istradefylline with strong CYP3A4 inducers.

            • ivosidenib

              butalbital will decrease the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of ivosidenib with strong CYP3A4 inducers decreased ivosidenib plasma concentrations.

            • larotrectinib

              butalbital will decrease the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of larotrectinib with strong CYP3A4 inducers is unavoidable, double larotrectinib dose. Resume prior larotrectinib dose once CYP3A4 inducer discontinued for 3-5 half-lives.

            • lefamulin

              butalbital will decrease the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lefamulin with strong or moderate CYP3A inducers unless the benefit outweighs risks. Monitor for reduced efficacy.

            • lemborexant

              butalbital will decrease the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              lemborexant, butalbital. Either increases effects of the other by sedation. Avoid or Use Alternate Drug. Use of lemborexant with other drugs to treat insomnia is not recommended.

            • lenacapavir

              butalbital will decrease the level or effect of lenacapavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lenacapavir with moderate CYP3A4 inducers.

            • 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.

            • lovastatin

              butalbital will decrease the level or effect of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • lumateperone

              butalbital will decrease the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • lurbinectedin

              butalbital will decrease the level or effect of lurbinectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • macimorelin

              butalbital will decrease the level or effect of macimorelin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for false positive test results if macimorelin and strong CYP3A4 inducers are coadministered. Discontinue strong CYP3A4 inducer, allowing for sufficient washout time, before testing.

            • mestranol

              butalbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.

            • methoxyflurane

              butalbital increases toxicity of methoxyflurane by increasing metabolism. Contraindicated. Increased metabolism of methoxyflurane to nephrotoxic compounds.

            • methylene blue

              methylene blue and butalbital both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

            • metoclopramide intranasal

              butalbital, 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.

            • midostaurin

              butalbital will decrease the level or effect of midostaurin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inducers may decrease midostaurin concentrations resulting in reduced efficacy.

            • mobocertinib

              butalbital will decrease the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • naldemedine

              butalbital will decrease the level or effect of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with strong CYP3A4 inducers.

            • neratinib

              butalbital will decrease the level or effect of neratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of neratinib with strong/moderate CYP3A4 inducers.

            • olopatadine intranasal

              butalbital 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.

            • olutasidenib

              butalbital will decrease the level or effect of olutasidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong or moderate CYP3A inducers decrease olutasidenib (a CYP3A4 substrate) plasma concentrations and efficacy.

            • pemigatinib

              butalbital will decrease the level or effect of pemigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • 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.

              butalbital will decrease the level or effect of pexidartinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • phenindione

              butalbital decreases effects of phenindione by increasing metabolism. Avoid or Use Alternate Drug.

            • 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 (316)

            • abiraterone

              butalbital will decrease the level or effect of abiraterone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • acalabrutinib

              butalbital will decrease the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • acebutolol

              butalbital decreases levels of acebutolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • albuterol

              butalbital increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • alfentanil

              butalbital and alfentanil both increase sedation. Use Caution/Monitor.

            • almotriptan

              butalbital will decrease the level or effect of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • alprazolam

              butalbital will decrease the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital and alprazolam both increase sedation. Use Caution/Monitor.

            • amiodarone

              butalbital will decrease the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • amitriptyline

              butalbital will decrease the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

              butalbital and amitriptyline both increase sedation. Use Caution/Monitor.

            • amlodipine

              butalbital will decrease the level or effect of amlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • amobarbital

              amobarbital and butalbital both increase sedation. Use Caution/Monitor.

            • amoxapine

              butalbital and amoxapine both increase sedation. Use Caution/Monitor.

            • 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.

            • apomorphine

              butalbital and apomorphine both increase sedation. Use Caution/Monitor.

            • aprepitant

              butalbital will decrease the level or effect of aprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • arformoterol

              butalbital increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • aripiprazole

              butalbital will decrease the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital and aripiprazole both increase sedation. Use Caution/Monitor.

            • armodafinil

              butalbital increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • artemether/lumefantrine

              butalbital will decrease the level or effect of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • atenolol

              butalbital decreases levels of atenolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • atogepant

              acetaminophen will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Recommended atogepant dosage with concomitant use of strong or moderate CYP3A4 inducers is 30 mg or 60 mg qDay.

            • atorvastatin

              butalbital will decrease the level or effect of atorvastatin 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.

            • avanafil

              butalbital will decrease the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. For patients with ED, monitor response carefully because of potential for decreased effectiveness

            • axitinib

              acetaminophen increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • azelastine

              azelastine and butalbital both increase sedation. Use Caution/Monitor.

            • baclofen

              butalbital and baclofen both increase sedation. Use Caution/Monitor.

            • bazedoxifene/conjugated estrogens

              butalbital will decrease the level or effect of bazedoxifene/conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • belladonna and opium

              butalbital and belladonna and opium both increase sedation. Use Caution/Monitor.

            • belumosudil

              butalbital will decrease the level or effect of belumosudil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase belumosudil dosage to 200 mg PO BID when coadministered with strong CYP3A inducers.

            • benazepril

              butalbital increases toxicity of benazepril by unspecified interaction mechanism. Use Caution/Monitor.

            • benperidol

              butalbital and benperidol both increase sedation. Use Caution/Monitor.

            • benzphetamine

              butalbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • betaxolol

              butalbital decreases levels of betaxolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • bisoprolol

              butalbital decreases levels of bisoprolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • bortezomib

              butalbital will decrease the level or effect of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • brexanolone

              brexanolone, butalbital. Either increases toxicity of the other by sedation. Use Caution/Monitor.

            • brompheniramine

              brompheniramine and butalbital both increase sedation. Use Caution/Monitor.

            • budesonide

              butalbital will decrease the level or effect of budesonide 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.

            • buprenorphine

              butalbital and buprenorphine both increase sedation. Use Caution/Monitor.

            • buprenorphine buccal

              butalbital and buprenorphine buccal both increase sedation. Use Caution/Monitor.

            • buprenorphine, long-acting injection

              butalbital will decrease the level or effect of buprenorphine, long-acting injection by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Patients who transfer to buprenorphine long-acting injection from transmucosal buprenorphine coadministered with CYP3A4 inducers should be monitored to ensure buprenorphine plasma levels are adequate. If the buprenorphine dose is inadequate and the CYP3A4 inducer cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.

              butalbital increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

            • bupropion

              butalbital, bupropion. increasing metabolism. Use Caution/Monitor. Decr levels of bupropion, but incr levels of active metabolites. .

            • buspirone

              butalbital will decrease the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. 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

              butabarbital and butalbital both increase sedation. Use Caution/Monitor.

            • butorphanol

              butalbital and butorphanol both increase sedation. Use Caution/Monitor.

            • caffeine

              butalbital increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • cannabidiol

              butalbital will decrease the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider an increase in cannabidiol dosage (based on clinical response and tolerability) when coadministered with a strong CYP3A4 inducer.

            • captopril

              butalbital, captopril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Enhanced hypotensive effects.

            • carbamazepine

              butalbital will decrease the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • carbinoxamine

              carbinoxamine and butalbital both increase sedation. Use Caution/Monitor.

            • carisoprodol

              butalbital and carisoprodol both increase sedation. Use Caution/Monitor.

            • carvedilol

              butalbital will decrease the level or effect of carvedilol by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

              butalbital decreases levels of carvedilol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • celiprolol

              butalbital decreases levels of celiprolol by increasing metabolism. Use Caution/Monitor. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • cenobamate

              cenobamate, butalbital. Either increases effects of the other by sedation. Use Caution/Monitor.

            • chloral hydrate

              butalbital and chloral hydrate both increase sedation. Use Caution/Monitor.

            • chlordiazepoxide

              butalbital and chlordiazepoxide both increase sedation. Use Caution/Monitor.

            • chlorpheniramine

              chlorpheniramine and butalbital both increase sedation. Use Caution/Monitor.

            • chlorpromazine

              butalbital and chlorpromazine both increase sedation. Use Caution/Monitor.

            • chlorzoxazone

              butalbital and chlorzoxazone both increase sedation. Use Caution/Monitor.

            • cilostazol

              butalbital will decrease the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cinacalcet

              butalbital will decrease the level or effect of cinacalcet by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cinnarizine

              cinnarizine and butalbital both increase sedation. Use Caution/Monitor.

            • clemastine

              clemastine and butalbital both increase sedation. Use Caution/Monitor.

            • clomipramine

              butalbital will decrease the level or effect of clomipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

              butalbital and clomipramine both increase sedation. Use Caution/Monitor.

            • clonazepam

              butalbital and clonazepam both increase sedation. Use Caution/Monitor.

            • clopidogrel

              butalbital will increase the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers may increase the metabolism of clopidogrel to its active metabolite. Monitor patients for potential increase in antiplatelet effects when CYP3A4 inducers are used in combination with clopidogrel

            • clorazepate

              butalbital and clorazepate both increase sedation. Use Caution/Monitor.

            • clozapine

              butalbital will decrease the level or effect of clozapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital and clozapine both increase sedation. Use Caution/Monitor.

            • codeine

              butalbital and codeine both increase sedation. Use Caution/Monitor.

            • colchicine

              butalbital will decrease the level or effect of colchicine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • conivaptan

              butalbital will decrease the level or effect of conivaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • conjugated estrogens

              butalbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • conjugated estrogens, vaginal

              butalbital will decrease the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cortisone

              butalbital will decrease the level or effect of cortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cyclizine

              cyclizine and butalbital both increase sedation. Use Caution/Monitor.

            • cyclobenzaprine

              butalbital and cyclobenzaprine both increase sedation. Use Caution/Monitor.

            • cyclosporine

              butalbital will decrease the level or effect of cyclosporine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cyproheptadine

              cyproheptadine and butalbital both increase sedation. Use Caution/Monitor.

            • dantrolene

              butalbital 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

              butalbital 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

              butalbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • darunavir

              butalbital will decrease the level or effect of darunavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dasatinib

              butalbital will decrease the level or effect of dasatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • desipramine

              butalbital will decrease the level or effect of desipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

              butalbital and desipramine both increase sedation. Use Caution/Monitor.

            • deutetrabenazine

              butalbital and deutetrabenazine both increase sedation. Use Caution/Monitor.

            • dexamethasone

              butalbital will decrease the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dexchlorpheniramine

              dexchlorpheniramine and butalbital both increase sedation. Use Caution/Monitor.

            • dexfenfluramine

              butalbital increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dexmedetomidine

              butalbital and dexmedetomidine both increase sedation. Use Caution/Monitor.

            • dexmethylphenidate

              butalbital increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dextroamphetamine

              butalbital increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dextromoramide

              butalbital and dextromoramide both increase sedation. Use Caution/Monitor.

            • diamorphine

              butalbital and diamorphine both increase sedation. Use Caution/Monitor.

            • diazepam

              butalbital will decrease the level or effect of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital and diazepam both increase sedation. Use Caution/Monitor.

            • diazepam intranasal

              butalbital will decrease the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inducers may increase rate of diazepam elimination; therefore, efficacy of diazepam may be decreased.

              diazepam intranasal, butalbital. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.

            • diethylpropion

              butalbital increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • difelikefalin

              difelikefalin and butalbital both increase sedation. Use Caution/Monitor.

            • difenoxin hcl

              butalbital and difenoxin hcl both increase sedation. Use Caution/Monitor.

            • diltiazem

              butalbital will decrease the level or effect of diltiazem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dimenhydrinate

              dimenhydrinate and butalbital both increase sedation. Use Caution/Monitor.

            • diphenhydramine

              diphenhydramine and butalbital both increase sedation. Use Caution/Monitor.

            • diphenoxylate hcl

              butalbital and diphenoxylate hcl both increase sedation. Use Caution/Monitor.

            • dipipanone

              butalbital and dipipanone both increase sedation. Use Caution/Monitor.

            • dobutamine

              butalbital increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dopamine

              butalbital increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dopexamine

              butalbital increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dosulepin

              butalbital and dosulepin both increase sedation. Use Caution/Monitor.

            • doxepin

              butalbital and doxepin both increase sedation. Use Caution/Monitor.

            • doxycycline

              butalbital decreases levels of doxycycline by increasing metabolism. Use Caution/Monitor.

            • doxylamine

              butalbital and doxylamine both increase sedation. Use Caution/Monitor.

            • dronabinol

              butalbital will increase the level or effect of dronabinol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dronabinol is a CYP3A4 substrate.

            • droperidol

              butalbital and droperidol both increase sedation. Use Caution/Monitor.

            • elagolix

              butalbital will decrease the level or effect of elagolix by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • eletriptan

              butalbital will decrease the level or effect of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • eltrombopag

              eltrombopag increases levels of acetaminophen by decreasing metabolism. Use Caution/Monitor. UGT inhibition; significance of interaction unclear.

              butalbital will decrease the level or effect of eltrombopag by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of eltrombopag by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

            • ephedrine

              butalbital increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. 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.

            • epinephrine

              butalbital increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • epinephrine racemic

              butalbital increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • erlotinib

              butalbital will decrease the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • escitalopram

              butalbital will decrease the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

            • esketamine intranasal

              esketamine intranasal, butalbital. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

            • esmolol

              butalbital decreases levels of esmolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • estazolam

              butalbital and estazolam both increase sedation. Use Caution/Monitor.

            • estradiol

              butalbital will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estradiol vaginal

              butalbital will decrease the level or effect of estradiol vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estrogens conjugated synthetic

              butalbital will decrease the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estropipate

              butalbital will decrease the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ethanol

              butalbital and ethanol both increase sedation. Use Caution/Monitor.

            • ethotoin

              butalbital will decrease the level or effect of ethotoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

            • etomidate

              etomidate and butalbital both increase sedation. Use Caution/Monitor.

            • etonogestrel

              butalbital will decrease the level or effect of etonogestrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • etravirine

              butalbital will decrease the level or effect of etravirine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of etravirine by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • 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.

            • felodipine

              butalbital will decrease the level or effect of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fenfluramine

              butalbital increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • fesoterodine

              butalbital will decrease the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. 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.

            • flibanserin

              butalbital 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

              butalbital will decrease the level or effect of fludrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • 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.

            • fluphenazine

              butalbital and fluphenazine both increase sedation. Use Caution/Monitor.

            • flurazepam

              butalbital and flurazepam both increase sedation. Use Caution/Monitor.

            • formoterol

              butalbital increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • fosamprenavir

              butalbital will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fosaprepitant

              butalbital will decrease the level or effect of fosaprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fosphenytoin

              butalbital will decrease the level or effect of fosphenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

            • gabapentin

              gabapentin, butalbital. 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.

            • gabapentin enacarbil

              gabapentin enacarbil, butalbital. 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.

            • ganaxolone

              butalbital and ganaxolone both increase sedation. Use Caution/Monitor.

            • glecaprevir/pibrentasvir

              butalbital will decrease the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of drugs that induce CYP3A4 with glecaprevir/pibrentasvir may decrease glecaprevir/pibrentasvir plasma concentrations. Potential for loss of therapeutic effect.

            • gotu kola

              gotu kola increases effects of butalbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

            • guanfacine

              butalbital will decrease the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inducers significantly reduce guanfacine plasma concentrations and elimination half-life. If coadministered, more frequent dosing of the IR product may be required to achieve or maintain the desired hypotensive response. For patients with ADHD, FDA-approved labeling for ER guanfacine recommends that, if coadministered, doubling the recommended dose of guanfacine should be considered.

            • haloperidol

              butalbital and haloperidol both increase sedation. Use Caution/Monitor.

            • hawthorn

              hawthorn increases effects of butalbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

            • hemin

              butalbital decreases effects of hemin by pharmacodynamic antagonism. Use Caution/Monitor. Drugs that increase delta-aminolevulinic acid synthetase may decrease hemin effect.

            • hops

              hops increases effects of butalbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

            • hydrocortisone

              butalbital will decrease the level or effect of hydrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • hydromorphone

              butalbital and hydromorphone both increase sedation. Use Caution/Monitor.

            • hydroxyprogesterone caproate

              butalbital will decrease the level or effect of hydroxyprogesterone caproate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • hydroxyzine

              hydroxyzine and butalbital both increase sedation. Use Caution/Monitor.

            • ifosfamide

              butalbital increases effects of ifosfamide by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor. Coadministration of ifosfamide with CYP2B6 inducers may increase metabolism of ifosfamide to its metabolite. Monitor for increased effects/toxicities if combined with CYP2B6 inducers.

              butalbital increases effects of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers may increase the metabolism of ifosfamide to its active alkylating metabolites. CYP3A4 inducers may increase the formation of the neurotoxic/nephrotoxic ifosfamide metabolite, chloroacetaldehyde. Closely monitor patients taking ifosfamide with CYP3A4 inducers for toxicities and consider dose adjustment.

            • iloperidone

              butalbital will decrease the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital and iloperidone both increase sedation. Use Caution/Monitor.

            • imipramine

              butalbital will decrease the level or effect of imipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of imipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

              butalbital and imipramine both increase sedation. Use Caution/Monitor.

            • indinavir

              butalbital will decrease the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • 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

              butalbital increases and isoproterenol decreases sedation. 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 .

            • ixabepilone

              butalbital will decrease the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • kava

              kava increases effects of butalbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

            • ketamine

              ketamine and butalbital both increase sedation. Use Caution/Monitor.

            • ketotifen, ophthalmic

              butalbital and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.

            • labetalol

              butalbital decreases levels of labetalol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • lapatinib

              butalbital will decrease the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lasmiditan

              lasmiditan, butalbital. 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.

            • 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.

            • levalbuterol

              butalbital increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • levamlodipine

              butalbital will decrease the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No information is available on the quantitative effects of CYP3A4 inducers on amlodipine. Closely monitor blood pressure when amlodipine is coadministered with CYP3A4 inducers.

            • levonorgestrel oral/ethinylestradiol/ferrous bisglycinate

              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.

              butalbital will decrease the level or effect of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. The efficacy of hormonal contraceptives may be reduced. Use an alternative method of contraception or a backup method when enzyme inducers are used with combined hormonal contraceptives (CHCs), and continue backup contraception for 28 days after discontinuing enzyme inducer to ensure contraceptive reliability.

              levonorgestrel oral/ethinylestradiol/ferrous bisglycinate will decrease the level or effect of acetaminophen by unknown mechanism. Use Caution/Monitor.

            • levorphanol

              butalbital and levorphanol both increase sedation. Use Caution/Monitor.

            • lixisenatide

              lixisenatide 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.

            • lidocaine

              butalbital will decrease the level or effect of lidocaine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

            • lisdexamfetamine

              butalbital increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • lofepramine

              butalbital and lofepramine both increase sedation. Use Caution/Monitor.

            • lofexidine

              butalbital 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.

            • lopinavir

              butalbital will decrease the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • loprazolam

              butalbital and loprazolam both increase sedation. Use Caution/Monitor.

            • loratadine

              butalbital will decrease the level or effect of loratadine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lorazepam

              butalbital and lorazepam both increase sedation. Use Caution/Monitor.

            • lormetazepam

              butalbital and lormetazepam both increase sedation. Use Caution/Monitor.

            • loxapine

              butalbital and loxapine both increase sedation. Use Caution/Monitor.

            • loxapine inhaled

              butalbital and loxapine inhaled both increase sedation. Use Caution/Monitor.

            • lumefantrine

              butalbital will decrease the level or effect of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lurasidone

              lurasidone, butalbital. 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

              butalbital and maprotiline both increase sedation. Use Caution/Monitor.

            • maraviroc

              butalbital will decrease the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • marijuana

              butalbital and marijuana both increase sedation. Use Caution/Monitor.

            • melatonin

              butalbital and melatonin both increase sedation. Use Caution/Monitor.

            • meperidine

              butalbital and meperidine both increase sedation. Use Caution/Monitor.

            • meprobamate

              butalbital and meprobamate both increase sedation. Use Caution/Monitor.

            • mestranol

              butalbital will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • metaproterenol

              butalbital increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • metaxalone

              butalbital and metaxalone both increase sedation. Use Caution/Monitor.

            • methadone

              butalbital will decrease the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital and methadone both increase sedation. Use Caution/Monitor.

            • methamphetamine

              butalbital increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • methocarbamol

              butalbital and methocarbamol both increase sedation. Use Caution/Monitor.

            • methylenedioxymethamphetamine

              butalbital increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • methylprednisolone

              butalbital will decrease the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • metoprolol

              butalbital decreases levels of metoprolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • mexiletine

              butalbital will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

            • midazolam

              butalbital will decrease the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital and midazolam both increase sedation. 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.

              midazolam intranasal, butalbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

            • midodrine

              butalbital 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

              butalbital and mirtazapine both increase sedation. Use Caution/Monitor.

            • modafinil

              butalbital increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • morphine

              butalbital and morphine both increase sedation. Use Caution/Monitor.

            • motherwort

              butalbital and motherwort both increase sedation. Use Caution/Monitor.

            • moxonidine

              butalbital and moxonidine both increase sedation. Use Caution/Monitor.

            • nabilone

              butalbital and nabilone both increase sedation. Use Caution/Monitor.

            • nadolol

              butalbital decreases levels of nadolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • nalbuphine

              butalbital and nalbuphine both increase sedation. Use Caution/Monitor.

            • nateglinide

              butalbital will decrease the level or effect of nateglinide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

            • nebivolol

              butalbital decreases levels of nebivolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • nelfinavir

              butalbital will decrease the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nicardipine

              butalbital will decrease the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nilotinib

              butalbital will decrease the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nisoldipine

              butalbital will decrease the level or effect of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • norepinephrine

              butalbital increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • nortriptyline

              butalbital and nortriptyline both increase sedation. Use Caution/Monitor.

            • olanzapine

              butalbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

              butalbital and olanzapine both increase sedation. Use Caution/Monitor.

            • oliceridine

              butalbital will decrease the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. If coadministration with a CYP3A4 inducer is necessary, consider increasing oliceridine dose until stable drug effects are achieved; monitor for signs of opioid withdrawal. If inducer is discontinued, consider oliceridine dosage reduction and monitor for signs of respiratory depression.

              oliceridine, butalbital. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. 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.

            • omeprazole

              butalbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

            • opium tincture

              butalbital and opium tincture both increase sedation. Use Caution/Monitor.

            • orphenadrine

              butalbital and orphenadrine both increase sedation. Use Caution/Monitor.

            • osilodrostat

              butalbital will decrease the level or effect of osilodrostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor cortisol concentration and patient?s signs and symptoms during coadministration or discontinuation with strong CYP3A4 inducers. Adjust dose of osilodrostat if necessary.

            • oxazepam

              butalbital and oxazepam both increase sedation. Use Caution/Monitor.

            • oxycodone

              butalbital and oxycodone both increase sedation. Use Caution/Monitor.

            • oxymorphone

              butalbital and oxymorphone both increase sedation. Use Caution/Monitor.

            • paliperidone

              butalbital and paliperidone both increase sedation. Use Caution/Monitor.

            • papaveretum

              butalbital and papaveretum both increase sedation. Use Caution/Monitor.

            • papaverine

              butalbital and papaverine both increase sedation. Use Caution/Monitor.

            • parecoxib

              butalbital will decrease the level or effect of parecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

            • passion flower

              passion flower increases effects of butalbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

            • pazopanib

              butalbital will decrease the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • penbutolol

              butalbital decreases levels of penbutolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • pentazocine

              butalbital and pentazocine both increase sedation. Use Caution/Monitor.

            • pentobarbital

              butalbital and pentobarbital both increase sedation. Use Caution/Monitor.

            • perphenazine

              butalbital and perphenazine both increase sedation. Use Caution/Monitor.

            • phendimetrazine

              butalbital increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • phenobarbital

              butalbital and phenobarbital both increase sedation. Use Caution/Monitor.

            • phentermine

              butalbital increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • phenylephrine

              butalbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • phenylephrine PO

              butalbital increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .

            • phenytoin

              butalbital will decrease the level or effect of phenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

            • pholcodine

              butalbital and pholcodine both increase sedation. Use Caution/Monitor.

            • pimozide

              butalbital and pimozide both increase sedation. Use Caution/Monitor.

            • pindolol

              butalbital decreases levels of pindolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • pirbuterol

              butalbital increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • pitolisant

              butalbital will decrease the level or effect of pitolisant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Pitolisant exposure is decreased by 50% if coadministered with strong CYP3A4 inducers. For patients stable on pitolisant 8.9 mg/day or 17.8 mg/day, double the pitolisant dose (ie, 17.8 mg or 35.6 mg, respectively) over 7 days. If the strong CYP3A4 inducer is discontinued, reduce pitolisant dosage by half.

            • polatuzumab vedotin

              butalbital will decrease the level or effect of polatuzumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Polatuzumab undergoes catabolism to small peptides, amino acids, monomethyl auristatin E (MMAE), and unconjugated MMAE-related catabolites. MMAE is a CYP3A4 substrate. Coadministration of polatuzumab vedotin with a strong CYP3A4 inducer may decrease unconjugated MMAE AUC.

            • prednisolone

              butalbital will decrease the level or effect of prednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • prednisone

              butalbital will decrease the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • pregabalin

              pregabalin, butalbital. 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

              butalbital and primidone both increase sedation. Use Caution/Monitor.

            • prochlorperazine

              butalbital and prochlorperazine both increase sedation. Use Caution/Monitor.

            • promethazine

              promethazine and butalbital both increase sedation. Use Caution/Monitor.

            • propafenone

              butalbital decreases levels of propafenone by increasing metabolism. Use Caution/Monitor.

            • propofol

              propofol and butalbital both increase sedation. Use Caution/Monitor.

            • propranolol

              butalbital decreases levels of propranolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • propylhexedrine

              butalbital increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • protriptyline

              butalbital and protriptyline both increase sedation. Use Caution/Monitor.

            • quazepam

              butalbital and quazepam both increase sedation. Use Caution/Monitor.

            • quetiapine

              butalbital will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              butalbital and quetiapine both increase sedation. Use Caution/Monitor.

            • quinidine

              butalbital will decrease the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ramelteon

              butalbital will decrease the level or effect of ramelteon by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

              butalbital and ramelteon both increase sedation. Use Caution/Monitor.

            • remimazolam

              remimazolam, butalbital. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.

            • repaglinide

              butalbital will decrease the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rifampin

              rifampin decreases levels of butalbital by increasing metabolism. Use Caution/Monitor.

            • risperidone

              butalbital and risperidone both increase sedation. Use Caution/Monitor.

            • ritonavir

              butalbital will decrease the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • salmeterol

              butalbital increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • saquinavir

              butalbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • scullcap

              butalbital and scullcap both increase sedation. Use Caution/Monitor.

            • secobarbital

              butalbital and secobarbital both increase sedation. Use Caution/Monitor.

            • shepherd's purse

              butalbital and shepherd's purse both increase sedation. Use Caution/Monitor.

            • sildenafil

              butalbital will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • solifenacin

              butalbital will decrease the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • sorafenib

              butalbital decreases levels of sorafenib by increasing metabolism. Use Caution/Monitor.

            • sotalol

              butalbital decreases levels of sotalol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • sufentanil

              butalbital and sufentanil both increase sedation. Use Caution/Monitor.

            • sufentanil SL

              butalbital decreases effects of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of CYP3A4 inducers may decrease sufentanil levels and efficacy, possibly precipitating withdrawal syndrome in patients who have developed physical dependence to sufentanil. Discontinuation of concomitantly used CYP3A4 inducers may increase sufentanil plasma concentration.

            • sunitinib

              butalbital will decrease the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tacrolimus

              butalbital will decrease the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tadalafil

              butalbital will decrease the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tapentadol

              butalbital 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.

            • temazepam

              butalbital and temazepam both increase sedation. Use Caution/Monitor.

            • temsirolimus

              butalbital will decrease the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • terbinafine

              butalbital will decrease the level or effect of terbinafine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • terbutaline

              butalbital increases and terbutaline decreases sedation. 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.

            • thalidomide

              thalidomide increases effects of butalbital by unspecified interaction mechanism. Use Caution/Monitor. Increased sedative effects.

            • theophylline

              butalbital will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

              butalbital will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • thioridazine

              butalbital and thioridazine both increase sedation. Use Caution/Monitor.

            • thiothixene

              butalbital and thiothixene both increase sedation. Use Caution/Monitor.

            • timolol

              butalbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

            • tinidazole

              butalbital will decrease the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              acetaminophen will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tipranavir

              butalbital will decrease the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • warfarin

              acetaminophen increases effects of warfarin by anticoagulation. Use Caution/Monitor.

            Minor (159)

            • acetazolamide

              acetazolamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

              acetazolamide, butalbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

            • albiglutide

              albiglutide decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

            • alfentanil

              butalbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • alfuzosin

              butalbital will decrease the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • alosetron

              butalbital will decrease the level or effect of alosetron by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

              butalbital will decrease the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • amitriptyline

              butalbital, amitriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • amoxapine

              butalbital, amoxapine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • amphotericin B deoxycholate

              butalbital decreases levels of amphotericin B deoxycholate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • antipyrine

              butalbital will decrease the level or effect of antipyrine by affecting hepatic enzyme CYP1A2 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.

            • armodafinil

              butalbital will decrease the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ascorbic acid

              butalbital decreases levels of ascorbic acid by increasing elimination. Minor/Significance Unknown.

            • asenapine

              butalbital will decrease the level or effect of asenapine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

            • ashwagandha

              ashwagandha increases effects of butalbital by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.

            • atazanavir

              butalbital will decrease the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. 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.

            • bosentan

              butalbital will decrease the level or effect of bosentan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

              butalbital will decrease the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • brimonidine

              brimonidine increases effects of butalbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

            • brinzolamide

              brinzolamide, butalbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

            • buprenorphine subdermal implant

              butalbital will decrease the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Monitor patients already on buprenorphine subdermal implant who require newly-initiated treatment with CYP3A4 inducer for signs and symptoms of withdrawal. If the dose of the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, implant removal may be necessary and the patient should then be treated with a buprenorphine dosage form that permits dose adjustments. If a CYP3A4 inducer is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for overmedication.

            • caffeine

              butalbital will decrease the level or effect of caffeine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

            • carbamazepine

              carbamazepine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

            • celecoxib

              butalbital will decrease the level or effect of celecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • cevimeline

              butalbital will decrease the level or effect of cevimeline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • chloramphenicol

              chloramphenicol increases levels of butalbital by decreasing metabolism. Minor/Significance Unknown.

              butalbital decreases levels of chloramphenicol by increasing metabolism. Minor/Significance Unknown.

            • chlorpromazine

              butalbital decreases levels of chlorpromazine by increasing metabolism. 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.

            • cimetidine

              butalbital will decrease the level or effect of cimetidine by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

            • clarithromycin

              butalbital will decrease the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

              butalbital decreases levels of clarithromycin by increasing elimination. Minor/Significance Unknown.

            • clomipramine

              butalbital, clomipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • clonazepam

              clonazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

            • clotrimazole

              butalbital decreases levels of clotrimazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • cocaine topical

              butalbital will decrease the level or effect of cocaine topical by affecting hepatic enzyme CYP2B6 metabolism. Minor/Significance Unknown.

            • 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.

            • dapsone

              butalbital will decrease the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • desipramine

              butalbital, desipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • diazepam

              diazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

            • diclofenac

              butalbital will decrease the level or effect of diclofenac by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • disopyramide

              butalbital will decrease the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • disulfiram

              disulfiram will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Minor/Significance Unknown.

            • docetaxel

              butalbital will decrease the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • donepezil

              butalbital will decrease the level or effect of donepezil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • dosulepin

              butalbital, dosulepin. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • doxepin

              butalbital, doxepin. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • dutasteride

              butalbital will decrease the level or effect of dutasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • efavirenz

              butalbital will decrease the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • enoxaparin

              acetaminophen increases effects of enoxaparin by unknown mechanism. Minor/Significance Unknown.

            • eplerenone

              butalbital will decrease the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • erythromycin base

              butalbital decreases levels of erythromycin base by increasing elimination. Minor/Significance Unknown.

            • erythromycin ethylsuccinate

              butalbital decreases levels of erythromycin ethylsuccinate by increasing elimination. Minor/Significance Unknown.

            • erythromycin lactobionate

              butalbital decreases levels of erythromycin lactobionate by increasing elimination. Minor/Significance Unknown.

            • erythromycin stearate

              butalbital decreases levels of erythromycin stearate by increasing elimination. 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.

              ethosuximide decreases effects of butalbital by pharmacodynamic antagonism. Minor/Significance Unknown.

            • eucalyptus

              butalbital will decrease the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

              butalbital 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.

            • finasteride

              butalbital will decrease the level or effect of finasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • fluconazole

              butalbital decreases levels of fluconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • flurbiprofen

              butalbital will decrease the level or effect of flurbiprofen by affecting hepatic enzyme CYP2C9/10 metabolism. 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.

            • frovatriptan

              butalbital will decrease the level or effect of frovatriptan by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

            • galantamine

              butalbital will decrease the level or effect of galantamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • green tea

              green tea increases effects of acetaminophen by pharmacodynamic synergism. Minor/Significance Unknown. (Theoretical, due to caffeine content).

            • griseofulvin

              butalbital decreases levels of griseofulvin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • haloperidol

              haloperidol, butalbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.

            • heparin

              acetaminophen increases effects of heparin by unknown mechanism. Minor/Significance Unknown.

            • ibuprofen

              butalbital will decrease the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • ibuprofen IV

              butalbital will decrease the level or effect of ibuprofen IV by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • imatinib

              butalbital will decrease the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • imipramine

              butalbital, imipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • isocarboxazid

              isocarboxazid increases levels of butalbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

            • isoniazid

              isoniazid increases toxicity of acetaminophen by unknown mechanism. Minor/Significance Unknown.

            • isradipine

              butalbital will decrease the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ketoconazole

              butalbital will decrease the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

              butalbital decreases levels of ketoconazole 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.

            • lansoprazole

              butalbital will decrease the level or effect of lansoprazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

            • levetiracetam

              levetiracetam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

            • levoketoconazole

              butalbital will decrease the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

              butalbital decreases levels of levoketoconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • levothyroxine

              butalbital decreases levels of levothyroxine by increasing metabolism. Minor/Significance Unknown.

            • linezolid

              linezolid increases levels of butalbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

            • liothyronine

              butalbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.

            • liraglutide

              liraglutide decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

            • lofepramine

              butalbital, lofepramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • lorazepam

              lorazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

            • losartan

              butalbital will decrease the level or effect of losartan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • maprotiline

              butalbital, maprotiline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • meloxicam

              butalbital will decrease the level or effect of meloxicam by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • methazolamide

              methazolamide, butalbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

            • methsuximide

              methsuximide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

              methsuximide decreases effects of butalbital by pharmacodynamic antagonism. Minor/Significance Unknown.

            • metoclopramide

              metoclopramide increases levels of acetaminophen by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • miconazole vaginal

              butalbital decreases levels of miconazole vaginal by inhibition of 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.

            • montelukast

              butalbital will decrease the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nettle

              nettle increases effects of butalbital by pharmacodynamic synergism. Minor/Significance Unknown. (High dose nettle; theoretical interaction) May enhance CNS depression.

            • nifedipine

              butalbital will decrease the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nimodipine

              butalbital will decrease the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nitrendipine

              butalbital will decrease the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nortriptyline

              butalbital, nortriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • 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.

              butalbital will decrease the level or effect of oxybutynin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • oxybutynin topical

              oxybutynin topical decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

            • paclitaxel

              butalbital will decrease the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • oxybutynin transdermal

              oxybutynin transdermal decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

            • paclitaxel protein bound

              butalbital will decrease the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • parecoxib

              butalbital will decrease the level or effect of parecoxib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • phenelzine

              phenelzine increases levels of butalbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

            • 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.

            • pimozide

              butalbital will decrease the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • pioglitazone

              butalbital will decrease the level or effect of pioglitazone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • piroxicam

              butalbital will decrease the level or effect of piroxicam by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • posaconazole

              butalbital decreases levels of posaconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • primidone

              primidone decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

            • propafenone

              butalbital will decrease the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • protamine

              acetaminophen increases effects of protamine by unknown mechanism. Minor/Significance Unknown.

            • protriptyline

              butalbital, protriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • quinine

              butalbital will decrease the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • rabeprazole

              butalbital will decrease the level or effect of rabeprazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

              butalbital will decrease the level or effect of rabeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ramelteon

              butalbital will decrease the level or effect of ramelteon by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

              butalbital will decrease the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. 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.

            • riluzole

              butalbital will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

            • rose hips

              butalbital decreases levels of rose hips by increasing elimination. 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

              butalbital and sage both increase sedation. Minor/Significance Unknown.

            • saxagliptin

              butalbital will decrease the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • selegiline transdermal

              selegiline transdermal increases levels of butalbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

            • Siberian ginseng

              Siberian ginseng increases effects of butalbital by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.

            • sufentanil

              butalbital will decrease the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • sulfamethoxazole

              butalbital will decrease the level or effect of sulfamethoxazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • tamoxifen

              butalbital will decrease the level or effect of tamoxifen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • thioridazine

              thioridazine decreases levels of butalbital by unspecified interaction mechanism. Minor/Significance Unknown.

            • thyroid desiccated

              butalbital decreases levels of thyroid desiccated by increasing metabolism. Minor/Significance Unknown.

            • tiagabine

              tiagabine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

            • tibolone

              butalbital decreases levels of tibolone by increasing metabolism. Minor/Significance Unknown. Theoretical interaction.

            • tolbutamide

              butalbital will decrease the level or effect of tolbutamide by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • topiramate

              topiramate decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

              butalbital decreases levels of topiramate by increasing metabolism. Minor/Significance Unknown.

            • tranylcypromine

              tranylcypromine increases levels of butalbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

            • valproic acid

              valproic acid decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

            • trazodone

              butalbital, trazodone. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • trimipramine

              butalbital, trimipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

            • vinblastine

              butalbital will decrease the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vincristine

              butalbital will decrease the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vincristine liposomal

              butalbital will decrease the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vinorelbine

              butalbital will decrease the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • voriconazole

              butalbital will decrease the level or effect of voriconazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

              butalbital will decrease the level or effect of voriconazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

            • zaleplon

              butalbital will decrease the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ziprasidone

              butalbital will decrease the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • zolpidem

              butalbital will decrease the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • zonisamide

              butalbital will decrease the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

              zonisamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism increase levels of hepatotoxic metabolites.

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            Adverse Effects

            Frequency Not Defined

            Butalbital

            • Dizziness, drowsiness, feeling of intoxication, lightheadedness, sedation
            • Abdominal pain, nausea, vomiting
            • Shortness of breath

            Acetaminophen

            • Angioedema, laryngeal edema
            • Pruritic maculopapular rash urticaria
            • Agranulocytosis, leukopenia, neutropenia, pancytopenia thrombocytopenia, thrombocytopenic purpura
            • Hepatotoxicity
            • Anaphylactoid reaction
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            Warnings

            Black Box Warnings

            Contains acetaminophen

            Hepatotoxicity may occur with acetaminophen doses that exceed 4 grams/day (ie, 4,000 mg/day)

            Acetaminophen associated with cases of acute liver failure, at times resulting in liver transplant and death

            Most cases of liver injury are associated with the use of acetaminophen at doses that exceed 4 grams/day, and often involve more than 1 acetaminophen-containing product

            New dosage limit allows no more than 325 mg/dosage unit for prescription medications that contain acetaminophen

            Healthcare professionals can direct patients to take 1 or 2 tablets, capsules or other dosage units of a prescription product containing 325 mg of acetaminophen up to 6 times a day (12 dosage units) and still not exceed the maximum daily dose of acetaminophen (ie, 4000 mg/day)

            Contraindications

            Hypersensitivity

            Hepatitis or severe hepatic/renal impairment

            Repeated administration in patients w/ anemia, cardiovascular, pulmonary, or renal disease

            Porphyria

            Cautions

            Acetaminophen associated with cases of acute liver failure, at times resulting in liver transplant and death; risk increases in individuals with underlying liver disease, alcohol ingestion, and/or use of more than 1 acetaminophen-containing product (see Black Box Warnings)

            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

            G6PD deficiency

            Avoid driving car or operating machinery

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            Pregnancy & Lactation

            Pregnancy category: C

            Lactation: excreted in breast milk; caution advised

            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.

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            Pharmacology

            Mechanism of Action

            Butalbital: Barbiturate; elicits generalized CNS depressant effects

            Acts on hypothalamus to produce antipyresis; may work peripherally to pain impulse generation; may also inhibit prostaglandin synthesis in CNS

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            Images

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            Patient Handout

            A Patient Handout is not currently available for this monograph.
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            Formulary

            FormularyPatient Discounts

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            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
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            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.