the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).dexchlorpheniraminedexchlorpheniramine and amitriptyline both increase sedation. Use Caution/Monitor.dexfenfluramineamitriptyline increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.amitriptyline and dexfenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.dexmedetomidinedexmedetomidine and amitriptyline both increase sedation. Use Caution/Monitor.dexmethylphenidateamitriptyline increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dextroamphetamineamitriptyline increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.amitriptyline and dextroamphetamine both increase serotonin levels. Modify Therapy/Monitor Closely.amitriptyline increases effects of dextroamphetamine by unknown mechanism. Use Caution/Monitor.dextroamphetamine transdermalamitriptyline will increase the level or effect of dextroamphetamine transdermal by pharmacodynamic synergism. Modify Therapy/Monitor Closely. May enhance the activity of tricyclic or sympathomimetic agents causing striking and sustained increases in dextroamphetamine levels in brain; May be potentiate cardiovascular effects. Monitor frequently and adjust or use an alternant based on clinical response.dextromoramidedextromoramide and amitriptyline both increase sedation. Use Caution/Monitor.diamorphinediamorphine and amitriptyline both increase sedation. Use Caution/Monitor.diazepamdiazepam and amitriptyline both increase sedation. Use Caution/Monitor.diazepam intranasaldiazepam intranasal, amitriptyline. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.dicyclominedicyclomine and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.diethylpropionamitriptyline increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.difelikefalindifelikefalin and amitriptyline both increase sedation. Use Caution/Monitor.difenoxin hcldifenoxin hcl and amitriptyline both increase sedation. Use Caution/Monitor.dihydroergotamineamitriptyline and dihydroergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.dihydroergotamine intranasalamitriptyline and dihydroergotamine intranasal both increase serotonin levels. Modify Therapy/Monitor Closely.diltiazemdiltiazem will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Concomitant use with amitriptyline may alter blood pressure control.dimenhydrinatedimenhydrinate and amitriptyline both increase sedation. Use Caution/Monitor.diphenhydraminediphenhydramine and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.diphenhydramine and amitriptyline both increase sedation. Use Caution/Monitor.diphenoxylate hcldiphenoxylate hcl and amitriptyline both increase sedation. Use Caution/Monitor.dipipanonedipipanone and amitriptyline both increase sedation. Use Caution/Monitor.dobutamineamitriptyline increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dofetilidedofetilide increases toxicity of amitriptyline by QTc interval. Use Caution/Monitor.dolasetronamitriptyline and dolasetron both increase QTc interval. Modify Therapy/Monitor Closely.donepezildonepezil increases and amitriptyline decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.donepezil and amitriptyline both increase QTc interval. Use Caution/Monitor.dopamineamitriptyline increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dopexamineamitriptyline increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dosulepinamitriptyline and dosulepin both decrease cholinergic effects/transmission. Use Caution/Monitor.amitriptyline and dosulepin both increase sedation. Use Caution/Monitor.doxepinamitriptyline and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.amitriptyline and doxepin both increase sedation. Use Caution/Monitor.doxylaminedoxylamine and amitriptyline both increase sedation. Use Caution/Monitor.droperidoldroperidol and amitriptyline both increase sedation. Use Caution/Monitor.echothiophate iodideechothiophate iodide increases and amitriptyline decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.efavirenzefavirenz will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.efavirenz will decrease the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.efavirenz and amitriptyline both increase QTc interval. Use Caution/Monitor.elagolixelagolix will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.eletriptaneletriptan and amitriptyline both increase serotonin levels. Modify Therapy/Monitor Closely.eliglustateliglustat increases levels of amitriptyline by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.eliglustat increases levels of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.eliglustat and amitriptyline both increase QTc interval. Use Caution/Monitor.elvitegravir/cobicistat/emtricitabine/tenofovir DFelvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of amitriptyline by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.entrectinibentrectinib and amitriptyline both increase QTc interval. Use Caution/Monitor.ephedrineamitriptyline increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.amitriptyline increases effects of ephedrine by unknown mechanism. Use Caution/Monitor.epinephrineamitriptyline increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.amitriptyline increases effects of epinephrine by unknown mechanism. Use Caution/Monitor.epinephrine inhaledamitriptyline and epinephrine inhaled both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Tricyclic antidepressants may potentiate epinephrine effect on cardiovascular system.epinephrine racemicamitriptyline increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.amitriptyline increases effects of epinephrine racemic by unknown mechanism. Use Caution/Monitor.ergotamineamitriptyline and ergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.eribulineribulin and amitriptyline both increase QTc interval. Use Caution/Monitor.esketamine intranasalesketamine intranasal, amitriptyline. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.eslicarbazepine acetateeslicarbazepine acetate will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.esomeprazoleesomeprazole will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.estazolamestazolam and amitriptyline both increase sedation. Use Caution/Monitor.ethanolamitriptyline and ethanol both increase sedation. Use Caution/Monitor.etomidateetomidate and amitriptyline both increase sedation. Use Caution/Monitor.etravirineetravirine will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.ezogabineezogabine, amitriptyline. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.fedratinibfedratinib will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.felbamatefelbamate will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.felodipinefelodipine will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.fenfluramineamitriptyline increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.amitriptyline and fenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.fenfluramine, amitriptyline. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration with drugs that increase serotoninergic effects may increase the risk of serotonin syndrome.fesoterodinefesoterodine and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.fingolimodfingolimod and amitriptyline both increase QTc interval. Use Caution/Monitor.flavoxateflavoxate and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.flecainideamitriptyline and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.fluconazolefluconazole will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.fluconazole will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fluoxetineamitriptyline and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.fluphenazinefluphenazine and amitriptyline both increase sedation. Use Caution/Monitor.flurazepamflurazepam and amitriptyline both increase sedation. Use Caution/Monitor.fluvoxaminefluvoxamine and amitriptyline both increase QTc interval. Modify Therapy/Monitor Closely.formoterolamitriptyline increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.fosamprenavirfosamprenavir will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fosaprepitantfosaprepitant will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.foscarnetamitriptyline and foscarnet both increase QTc interval. Modify Therapy/Monitor Closely.fosphenytoinfosphenytoin will decrease the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fosphenytoin will decrease the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.fostemsaviramitriptyline and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. frovatriptanfrovatriptan and amitriptyline both increase serotonin levels. Modify Therapy/Monitor Closely.gabapentingabapentin, amitriptyline. 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 enacarbilgabapentin enacarbil, amitriptyline. 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.galantaminegalantamine increases and amitriptyline decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.ganaxoloneamitriptyline and ganaxolone both increase sedation. Use Caution/Monitor.gemifloxacingemifloxacin and amitriptyline both increase QTc interval. Use Caution/Monitor.gilteritinibgilteritinib and amitriptyline both increase QTc interval. Use Caution/Monitor.glecaprevir/pibrentasvirglecaprevir/pibrentasvir will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely.glycopyrrolateglycopyrrolate and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.amitriptyline increases levels of glycopyrrolate by unknown mechanism. Use Caution/Monitor.glycopyrrolate inhaledglycopyrrolate inhaled and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.amitriptyline increases levels of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.glycopyrronium tosylate topicalglycopyrronium tosylate topical, amitriptyline. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.grapefruitgrapefruit will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.haloperidolhaloperidol and amitriptyline both increase sedation. Use Caution/Monitor.henbanehenbane and amitriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.homatropinehomatropine and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.huperzine Ahuperzine A increases and amitriptyline decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.hydrocodonehydrocodone, amitriptyline. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.hydromorphonehydromorphone and amitriptyline both increase sedation. Use Caution/Monitor.hydroxyzinehydroxyzine and amitriptyline both increase sedation. Use Caution/Monitor.hydroxyzine and amitriptyline both increase QTc interval. Use Caution/Monitor.hyoscyaminehyoscyamine and amitriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.hyoscyamine sprayhyoscyamine spray and amitriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.iloperidoneamitriptyline and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely.iloperidone and amitriptyline both increase sedation. Use Caution/Monitor.imipramineamitriptyline and imipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.amitriptyline and imipramine both increase sedation. Use Caution/Monitor.indacaterol, inhaledindacaterol, inhaled, amitriptyline. QTc interval. Use Caution/Monitor. Indacaterol should be administered with extreme caution to patients treated with TCAs. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.indinavirindinavir will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.ipratropiumipratropium and amitriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor. Due to the poor systemic absorption of ipratropium, interaction unlikely at regularly recommended dosages.isofluraneisoflurane and amitriptyline both increase QTc interval. Use Caution/Monitor.isoniazidisoniazid will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.amitriptyline and isoniazid both increase serotonin levels. Modify Therapy/Monitor Closely.isoproterenolamitriptyline increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.istradefyllineistradefylline will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.itraconazoleitraconazole will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.itraconazole and amitriptyline both increase QTc interval. Use Caution/Monitor.ivacaftorivacaftor increases levels of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.ketamineketamine and amitriptyline both increase sedation. Use Caution/Monitor.ketoconazoleketoconazole will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ketoconazole will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.ketotifen, ophthalmicamitriptyline and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.L-tryptophanamitriptyline and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.lapatinibamitriptyline and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.lasmiditanlasmiditan, amitriptyline. 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.amitriptyline increases effects of lasmiditan by serotonin levels. Use Caution/Monitor. Coadministration may increase risk of serotonin syndrome.lemborexantlemborexant, amitriptyline. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.letermovirletermovir increases levels of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.levalbuterolamitriptyline increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.levofloxacinamitriptyline and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.levoketoconazolelevoketoconazole will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.levoketoconazole will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.levorphanollevorphanol and amitriptyline both increase sedation. Use Caution/Monitor.levothyroxinelevothyroxine increases effects of amitriptyline by