Quinidine Interactions

Itraconazole increases quinidine concentrations, potentially causing QT prolongation and Torsade de Pointes. Contraindicated during and 2 weeks after itraconazole treatment.

Source: NLP:itraconazole

Ketoconazole increases quinidine plasma concentrations, potentially causing QT prolongation and life-threatening ventricular tachyarrhythmias including torsades de pointes.

Source: NLP:ketoconazole

Concomitant use is contraindicated due to increased risk of QT prolongation and torsades de pointes.

Source: NLP:levoketoconazole

Mifepristone increases quinidine exposure; concomitant use is contraindicated due to narrow therapeutic range.

Source: NLP:mifepristone

Co-administration contraindicated due to potential for cardiac arrhythmias.

Source: NLP:nirmatrelvir and ritonavir

Completely inhibits CYP2D6 hydroxylation, increasing propafenone concentrations more than 2-fold; concomitant use should be avoided.

Source: NLP:propafenone hydrochloride

Class Ia antiarrhythmic; potential to prolong refractoriness. Discontinue for at least three half-lives prior to sotalol dosing.

Source: NLP:sotalol hydrochloride

CYP2D6 inhibitor that increases codeine plasma concentration but decreases morphine concentration, potentially causing reduced analgesic efficacy or opioid withdrawal symptoms. Discontinuation may cause increased morphine levels and potentially fatal respiratory depression.

Source: NLP:acetaminophen and codeine phosphate

Patients receiving quinidine should be observed carefully for development of cardiac arrhythmias.

Source: NLP:adrenalin (epinephrine)

Class I antiarrhythmic. Amiodarone inhibits quinidine metabolism. Reserve concomitant use; initiate at lower than usual dose and reduce previous dose by 30-50%.

Source: NLP:amiodarone hydrochloride

Quinidine inhibits cytochrome P450 2D6, potentially causing toxic amitriptyline levels in normal metabolizers; may require lower amitriptyline doses.

Source: NLP:amitriptyline hydrochloride

CYP2D6 inhibitor that increases amphetamine exposure and serotonin syndrome risk.

Source: NLP:amphetamine sulfate

CYP2D6 inhibitor that increases atomoxetine steady-state plasma concentrations in extensive metabolizers.

Source: NLP:atomoxetine

CYP2D6 inhibitor that increases atomoxetine steady-state plasma concentrations in extensive metabolizers.

Source: NLP:atomoxetine hydrochloride

CYP2D6 inhibitor may potentiate systemic beta-blockade with decreased heart rate and depression.

Source: NLP:brimonidine tartrate and timolol maleate

May prolong neuromuscular blockade action of cisatracurium besylate. Use peripheral nerve stimulator and monitor clinical signs.

Source: NLP:cisatracurium besylate

Postmarketing reports of torsades de pointes occurring with concurrent use of clarithromycin and quinidine. CYP3A-based interaction increases serum concentrations.

Source: NLP:clarithromycin

Inhibits P450 2D6 and may increase clomipramine plasma levels, potentially causing toxicity.

Source: NLP:clomipramine hydrochloride

Inhibits cytochrome P450 2D6, may increase desipramine plasma concentrations and risk of toxicity; dose adjustment may be necessary.

Source: NLP:desipramine hydrochloride

CYP2D6 inhibitor that increases amphetamine exposure and risk of serotonin syndrome. Initiate with lower doses and monitor for serotonin syndrome.

Source: NLP:dextroamphetamine saccharate, amphetamine aspartate, dextroamphetamine sulfate and amphetamine sulfate

CYP2D6 inhibitor that increases dextroamphetamine exposure and risk of serotonin syndrome. Initiate with lower doses and monitor for serotonin syndrome symptoms.

Source: NLP:dextroamphetamine sulfate

Digoxin serum concentrations increased 54-83%. Reduce digoxin dose by 30-50% and monitor serum concentrations.

Source: NLP:digoxin

Potent CYP2D6 inhibitor; expected to increase duloxetine concentrations.

Source: NLP:duloxetine

Potent CYP2D6 inhibitor expected to increase duloxetine concentrations.

Source: NLP:duloxetine hydrochloride

Potentiates arrhythmogenic effects of epinephrine.

Source: NLP:epinephrine

Increases the arrhythmogenic potential of epinephrine; patients should be observed carefully for cardiac arrhythmias.

Source: NLP:epinephrine in sodium chloride

Class Ia anti-arrhythmic drug that may increase risk of QT prolongation and Torsades de Pointes due to additive effects on heart rate and QT interval.

Source: NLP:etrasimod

Should be avoided due to risk of QT prolongation and torsades de pointes.

Source: NLP:foscarnet sodium

Inhibits cytochrome P450 2D6, reducing imipramine metabolism and increasing plasma concentrations. May cause abrupt toxicity in patients stable on imipramine doses.

Source: NLP:imipramine hydrochloride

Cardiac effects may be additive or antagonistic and toxic effects may be additive when administered with lidocaine.

Source: NLP:lidocaine hydrochloride

P-glycoprotein inhibitor increases loperamide plasma concentrations 2- to 3-fold with potential for enhanced CNS adverse reactions.

Source: NLP:loperamide hydrochloride

Strong CYP2D6 inhibitor that increases metoclopramide plasma concentrations and risk of extrapyramidal symptoms exacerbation. Dosage reduction recommended.

Source: NLP:metoclopramide

Strong CYP2D6 inhibitor increasing metoclopramide plasma concentrations with risk of exacerbation of extrapyramidal symptoms; dosage reduction recommended.

Source: NLP:metoclopramide hydrochloride

Strong CYP2D6 inhibitor that doubles metoprolol concentrations, decreasing cardioselectivity. Close monitoring required.

Source: NLP:metoprolol

Strong CYP2D6 inhibitor that doubles metoprolol concentrations, decreasing cardioselectivity and requiring close monitoring.

Source: NLP:metoprolol succinate

Strong CYP2D6 inhibitor that doubles metoprolol plasma concentrations, decreasing cardioselectivity. Close monitoring required.

Source: NLP:metoprolol succinate er tablets

Strong CYP2D6 inhibitor that doubles metoprolol concentrations, decreasing cardioselectivity. Close monitoring required.

Source: NLP:metoprolol tartrate

Inhibits cytochrome P450 2D6, which may cause abrupt toxicity in patients stable on nortriptyline by increasing plasma concentrations.

Source: NLP:nortriptyline hydrochloride

Concomitant administration of posaconazole with quinidine may increase quinidine concentrations, requiring dosage adjustment and monitoring for adverse effects.

Source: NLP:posaconazole

CYP2D6 inhibitor that reduces metabolism of propranolol, leading to 2-3 fold increased blood concentration and greater beta-blockade.

Source: NLP:propranolol hydrochloride

May enhance rocuronium bromide activity and neuromuscular blockade.

Source: NLP:rocuronium bromide

May enhance the neuromuscular blocking action of succinylcholine.

Source: NLP:succinylcholine chloride

Strong CYP2D6 inhibitor that markedly increases exposure to tetrabenazine metabolites. Dose reduction necessary; maximum daily dose 50 mg, maximum single dose 25 mg.

Source: NLP:tetrabenazine

CYP2D6 inhibitor that potentiates systemic beta-blockade, resulting in decreased heart rate.

Source: NLP:timolol hemihydrate

Potentiated systemic beta-blockade (decreased heart rate, depression) has been reported during combined treatment with this CYP2D6 inhibitor and timolol.

Source: NLP:timolol maleate

Potentiated systemic beta-blockade including decreased heart rate and depression has been reported during combined treatment.

Source: NLP:timolol maleate ophthalmic gel forming solution

CYP2D6 inhibitor may increase tramadol plasma concentration and decrease M1 concentration, resulting in increased risk of seizures, serotonin syndrome, and opioid withdrawal or toxicity.

Source: NLP:tramadol hydrochloride

CYP2D6 inhibitor that increases tramadol plasma concentration and decreases M1 concentration, risking seizures, serotonin syndrome, opioid withdrawal, and respiratory depression.

Source: NLP:tramadol hydrochloride and acetaminophen

CYP2D6 inhibitor may increase tramadol plasma concentration and decrease M1 concentration, resulting in increased risk of seizures, serotonin syndrome, and opioid withdrawal or toxicity.

Source: NLP:tramadol/apap

Quinidine administration during recovery from vecuronium may cause recurrent paralysis.

Source: NLP:vecuronium bromide

Acetazolamide reduces urinary excretion of quinidine and may enhance its effect.

Source: NLP:acetazolamide

Acetazolamide reduces urinary excretion of quinidine and may enhance its effect.

Source: NLP:acetazolamide extended-release

Reduces renal clearance of amantadine by approximately 30%.

Source: NLP:amantadine

Reduces renal clearance of amantadine hydrochloride by approximately 30%.

Source: NLP:amantadine hydrochloride

Strong CYP2D6 inhibitor increases aripiprazole exposure. Reduce aripiprazole dosage when used concomitantly.

Source: NLP:aripiprazole

Strong CYP2D6 inhibitor increases aripiprazole exposure. Dose reduction recommended with concomitant use for more than 2 weeks.

Source: NLP:aripiprazole lauroxil

May enhance the neuromuscular blocking action of atracurium.

Source: NLP:atracurium besylate

CYP2D6 inhibitor expected to increase blood levels of carvedilol R(+) enantiomer, potentially increasing vasodilating effects and dizziness.

Source: NLP:carvedilol

Potent CYP2D6 inhibitor expected to increase carvedilol R(+) enantiomer blood levels, potentially causing dizziness and vasodilation.

Source: NLP:carvedilol phosphate

CYP2D6 or CYP3A4 inhibitor that can increase clozapine levels and lead to adverse reactions. Close monitoring and dose reduction may be necessary.

Source: NLP:clozapine

Deferasirox may induce CYP3A4 resulting in decreased quinidine concentration. Monitor for reduced effectiveness.

Source: NLP:deferasirox

CYP2C19 inhibitor that decreases diazepam elimination, potentially increasing adverse reactions.

Source: NLP:diazepam

Class I antiarrhythmic agent may increase certain actions or side effects of dicyclomine hydrochloride.

Source: NLP:dicyclomine hydrochloride

Increased exposure of quinidine due to CYP3A4 inhibition; may require dose adjustment.

Source: NLP:diltiazem hydrochloride

Concurrent use may cause excessive QRS widening and/or Q-T prolongation. Slight increase in disopyramide levels and decrease in quinidine levels observed.

Source: NLP:disopyramide phosphate

CYP2D6 inhibitor may potentiate systemic beta-blockade, causing decreased heart rate and depression.

Source: NLP:dorzolamide hydrochloride and timolol maleate

Inhibits cytochrome P450 2D6, which may increase doxepin plasma concentrations. Concomitant use may require lower doses and monitoring of TCA plasma levels.

Source: NLP:doxepin hydrochloride

Potent CYP2D6 inhibitor expected to increase duloxetine concentrations.

Source: NLP:duloxetine d/r

Antagonizes pressor effect of ephedrine. Carefully monitor blood pressure.

Source: NLP:ephedrine sulfate

Quinidine, a cytochrome P450IID6 inhibitor, might increase plasma flecainide concentrations, especially in extensive metabolizers on chronic therapy.

Source: NLP:flecainide acetate

Glycerol phenylbutyrate may decrease systemic exposure. Monitor for decreased efficacy of this narrow therapeutic index drug.

Source: NLP:glycerol phenylbutyrate

Class 1A antiarrhythmic known to prolong QTc interval; caution advised when used with haloperidol decanoate due to risk of QT prolongation.

Source: NLP:haloperidol decanoate

Class 1A antiarrhythmic that prolongs QTc interval and inhibits CYP2D6; caution advised due to risk of QT prolongation and increased haloperidol levels.

Source: NLP:haloperidol lactate

Lanreotide may decrease metabolic clearance of quinidine; avoid concomitant use or consider dose reduction.

Source: NLP:lanreotide acetate

Cationic drug eliminated by renal tubular secretion with potential for interaction with metformin by competing for common renal tubular transport systems.

Source: NLP:metformin hcl

Strong CYP2D6 inhibitor that doubles metoprolol concentrations and decreases cardioselectivity. Monitor patients closely when combination cannot be avoided.

Source: NLP:metoprolol tartrate and hydrochlorothiazide

CYP3A4 substrate whose plasma levels may increase with concomitant metronidazole use. Monitor plasma concentrations.

Source: NLP:metronidazole

P-glycoprotein inhibitor increasing plasma naldemedine concentrations; monitor for adverse reactions.

Source: NLP:naldemedine

CYP2D6 inhibitor that may increase nebivolol levels; use caution when co-administered.

Source: NLP:nebivolol

CYP2D6 inhibitor may increase nebivolol levels. Use caution when co-administered.

Source: NLP:nebivolol hydrochloride

Amiodarone inhibits metabolism of quinidine; reduce dose and monitor carefully.

Source: NLP:nexterone (amiodarone hci)

CYP3A substrate and inhibitor that increases nifedipine C max and AUC by 2.30 and 1.37 fold respectively, with increased heart rate up to 17.9 beats/minute. Heart rate monitoring and nifedipine dose adjustment recommended.

Source: NLP:nifedipine

Octreotide may decrease metabolic clearance of quinidine through CYP3A4 suppression; use with caution due to low therapeutic index.

Source: NLP:octreotide acetate

CYP2D6 inhibitor that increases oliceridine plasma concentration, resulting in increased or prolonged opioid effects. May require less frequent dosing and close monitoring for respiratory depression.

Source: NLP:oliceridine

Patiromer binds quinidine, potentially reducing systemic exposure and clinical efficacy. Separate dosing by at least 3 hours.

Source: NLP:patiromer

Potent P-gp inhibitor that may increase rimegepant exposure. Avoid another dose within 48 hours when co-administered.

Source: NLP:rimegepant sulfate

Stiripentol is an inhibitor and inducer of CYP3A4; consider dose adjustment of quinidine when administered concomitantly with DIACOMIT.

Source: NLP:stiripentol

Sucralfate reduces the bioavailability of quinidine. Separate dosing administration is recommended.

Source: NLP:sucralfate oral

Quinidine inhibits cytochrome P450 2D6, reducing trimipramine maleate metabolism and increasing plasma concentrations. Patient may become abruptly toxic.

Source: NLP:trimipramine maleate

Strong CYP2D6 inhibitor increases plasma concentrations of vortioxetine. Reduce TRINTELLIX dose by half when coadministered.

Source: NLP:vortioxetine

P-gp inhibitor that does not require dosage adjustment of dabigatran etexilate.

Source: NLP:dabigatran etexilate

CYP2D6 inhibitor. No dosing adjustments recommended for darifenacin.

Source: NLP:darifenacin

CYP2D6 inhibitor; no dosing adjustments recommended.

Source: NLP:darifenacin hydrobromide

Administered without adverse drug interaction in limited clinical experience.

Source: NLP:prazosin hydrochloride

Quinidine inhibits CYP2D6, which inhibits donepezil metabolism in vitro; clinical effect is unknown.

Source: NLP:memantine hydrochloride and donepezil hydrochloride

Antiarrhythmic that has been used concurrently with mexiletine, sometimes with improved ventricular ectopy control.

Source: NLP:mexiletine hydrochloride

Potential for drug-drug interaction due to possible competition for active tubular secretion via base-secreting system.

Source: NLP:midodrine hydrochloride