Caution/Monitor.eletriptaneletriptan and doxepin both increase serotonin levels. Modify Therapy/Monitor Closely.eliglustateliglustat increases levels of doxepin 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.doxepin and eliglustat both increase QTc interval. Use Caution/Monitor.elvitegravir/cobicistat/emtricitabine/tenofovir DFelvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of doxepin 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.entrectinibdoxepin and entrectinib both increase QTc interval. Use Caution/Monitor.ephedrinedoxepin increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepin increases effects of ephedrine by unknown mechanism. Use Caution/Monitor.epinephrinedoxepin increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepin increases effects of epinephrine by unknown mechanism. Use Caution/Monitor.epinephrine inhaleddoxepin 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 racemicdoxepin increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepin increases effects of epinephrine racemic by unknown mechanism. Use Caution/Monitor.ergotaminedoxepin and ergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.eribulindoxepin and eribulin both increase QTc interval. Use Caution/Monitor.esketamine intranasalesketamine intranasal, doxepin. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.estazolamestazolam and doxepin both increase sedation. Use Caution/Monitor.ethanoldoxepin and ethanol both increase sedation. Use Caution/Monitor.etomidateetomidate and doxepin both increase sedation. Use Caution/Monitor.fedratinibfedratinib will increase the level or effect of doxepin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.fedratinib will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.fenfluraminedoxepin increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepin and fenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.fenfluramine, doxepin. 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 doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.fingolimodfingolimod and doxepin both increase QTc interval. Use Caution/Monitor.flavoxateflavoxate and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.flecainidedoxepin and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.fluoxetinedoxepin and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.fluphenazinefluphenazine and doxepin both increase sedation. Use Caution/Monitor.flurazepamflurazepam and doxepin both increase sedation. Use Caution/Monitor.formoteroldoxepin increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.foscarnetdoxepin and foscarnet both increase QTc interval. Modify Therapy/Monitor Closely.fostemsavirdoxepin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. frovatriptanfrovatriptan and doxepin both increase serotonin levels. Modify Therapy/Monitor Closely.gabapentingabapentin, doxepin. 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, doxepin. 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.gadobenategadobenate and doxepin both increase QTc interval. Use Caution/Monitor.galantaminegalantamine increases and doxepin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.ganaxolonedoxepin and ganaxolone both increase sedation. Use Caution/Monitor.gemifloxacindoxepin and gemifloxacin both increase QTc interval. Use Caution/Monitor.gemtuzumabdoxepin and gemtuzumab both increase QTc interval. Use Caution/Monitor.gilteritinibdoxepin and gilteritinib both increase QTc interval. Use Caution/Monitor.glycopyrrolateglycopyrrolate and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin increases levels of glycopyrrolate by unknown mechanism. Use Caution/Monitor.glycopyrrolate inhaledglycopyrrolate inhaled and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin increases levels of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.glycopyrronium tosylate topicalglycopyrronium tosylate topical, doxepin. 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.goserelindoxepin and goserelin both increase QTc interval. Use Caution/Monitor.granisetrondoxepin and granisetron both increase QTc interval. Use Caution/Monitor.haloperidolhaloperidol and doxepin both increase sedation. Use Caution/Monitor.henbanehenbane and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.histrelindoxepin and histrelin both increase QTc interval. Use Caution/Monitor.homatropinehomatropine and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.huperzine Ahuperzine A increases and doxepin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.hydrocodonehydrocodone, doxepin. 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 doxepin both increase sedation. Use Caution/Monitor.hydroxyzinehydroxyzine and doxepin both increase sedation. Use Caution/Monitor.doxepin and hydroxyzine both increase QTc interval. Use Caution/Monitor.hyoscyaminehyoscyamine and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.hyoscyamine sprayhyoscyamine spray and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.iloperidonedoxepin and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely.iloperidone and doxepin both increase sedation. Use Caution/Monitor.iloperidone increases levels of doxepin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.imatinibimatinib will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.imipraminedoxepin and imipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin and imipramine both increase sedation. Use Caution/Monitor.indacaterol, inhaledindacaterol, inhaled, doxepin. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.ipratropiumipratropium and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor. Due to the poor systemic absorption of ipratropium, interaction unlikely at regularly recommended dosages.isofluranedoxepin and isoflurane both increase QTc interval. Use Caution/Monitor.isoniaziddoxepin and isoniazid both increase serotonin levels. Modify Therapy/Monitor Closely.isoproterenoldoxepin increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.istradefyllineistradefylline will increase the level or effect of doxepin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.itraconazoleitraconazole and doxepin both increase QTc interval. Use Caution/Monitor.ketamineketamine and doxepin both increase sedation. Use Caution/Monitor.ketotifen, ophthalmicdoxepin and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.L-tryptophandoxepin and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.lapatinibdoxepin and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.lasmiditanlasmiditan, doxepin. 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.doxepin increases effects of lasmiditan by serotonin levels. Use Caution/Monitor. Coadministration may increase risk of serotonin syndrome.lefamulindoxepin and lefamulin both increase QTc interval. Use Caution/Monitor.lemborexantlemborexant, doxepin. 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.leuprolidedoxepin and leuprolide both increase QTc interval. Use Caution/Monitor.levalbuteroldoxepin increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepin and levalbuterol both increase QTc interval. Use Caution/Monitor.levofloxacindoxepin and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.levorphanollevorphanol and doxepin both increase sedation. Use Caution/Monitor.levothyroxinelevothyroxine increases effects of doxepin by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.liothyronineliothyronine increases effects of doxepin by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.liotrixliotrix increases effects of doxepin by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.lisdexamfetaminedoxepin increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepin, lisdexamfetamine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Initiate with lower doses and monitor for signs and symptoms of serotonin syndrome, particularly during initiation or dosage increase. If serotonin syndrome occurs, discontinue along with concomitant serotonergic drug(s).lithiumdoxepin and lithium both increase serotonin levels. Modify Therapy/Monitor Closely.doxepin and lithium both increase QTc interval. Use Caution/Monitor.lofepraminedoxepin and lofepramine both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin and lofepramine both increase sedation. Use Caution/Monitor.lofexidinedoxepin and lofexidine both increase sedation. Use Caution/Monitor.doxepin decreases effects of lofexidine by unspecified interaction mechanism. Use Caution/Monitor.doxepin and lofexidine both increase QTc interval. Use Caution/Monitor.loperamidedoxepin and loperamide both increase QTc interval. Use Caution/Monitor.loprazolamloprazolam and doxepin both increase sedation. Use Caution/Monitor.lorazepamlorazepam and doxepin both increase sedation. Use Caution/Monitor.lorcaserinlorcaserin will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.lormetazepamlormetazepam and doxepin both increase sedation. Use Caution/Monitor.loxapineloxapine and doxepin both increase sedation. Use Caution/Monitor.loxapine inhaledloxapine inhaled and doxepin both increase sedation. Use Caution/Monitor.lsddoxepin and lsd both increase serotonin levels. Modify Therapy/Monitor Closely.lurasidonelurasidone increases effects of doxepin by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed.maprotilinedoxepin and maprotiline both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin and maprotiline both increase sedation. Use Caution/Monitor.marijuanadoxepin and marijuana both increase sedation. Use Caution/Monitor.meclizinemeclizine and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.melatonindoxepin and melatonin both increase sedation. Use Caution/Monitor.meperidinemeperidine and doxepin both increase sedation. Use Caution/Monitor.meprobamatedoxepin and meprobamate both increase sedation. Use Caution/Monitor.metaproterenoldoxepin increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.metaxalonemetaxalone and doxepin both increase sedation. Use Caution/Monitor.methadonedoxepin and methadone both increase QTc interval. Modify Therapy/Monitor Closely.methadone and doxepin both increase sedation. Use Caution/Monitor.methamphetaminedoxepin increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methocarbamolmethocarbamol and doxepin both increase sedation. Use Caution/Monitor.methscopolaminemethscopolamine and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.methylenedioxymethamphetaminedoxepin increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methylphenidatedoxepin, methylphenidate. Other (see comment). Use Caution/Monitor. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.methylphenidate transdermalmethylphenidate transdermal will increase the level or effect of doxepin by decreasing elimination. Modify Therapy/Monitor Closely. Consider decreasing the dose of these drugs when given coadministered with methylphenidate. Monitor for drug toxiticities when initiating or discontinuing methylphenidate. midazolammidazolam and doxepin both increase sedation. Use Caution/Monitor.midazolam intranasalmidazolam intranasal, doxepin. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.midodrinedoxepin increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.mifepristonedoxepin and mifepristone both increase QTc interval. Use Caution/Monitor.mirabegronmirabegron will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.mirtazapinedoxepin and mirtazapine both increase sedation. Use Caution/Monitor.doxepin and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.mitotanemitotane decreases levels of doxepin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.mobocertinibdoxepin and mobocertinib both increase QTc interval. Use Caution/Monitor.modafinildoxepin increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.morphinemorphine and doxepin both increase sedation. Use Caution/Monitor.doxepin and morphine both increase serotonin levels. Modify Therapy/Monitor Closely.motherwortdoxepin and motherwort both increase sedation. Use Caution/Monitor.moxonidinedoxepin and moxonidine both increase sedation. Use Caution/Monitor.nabilonedoxepin and nabilone both increase sedation. Use Caution/Monitor.nalbuphinenalbuphine and doxepin both increase sedation. Use Caution/Monitor.naratriptannaratriptan and doxepin both increase serotonin levels. Modify Therapy/Monitor Closely.nefopamnefopam, doxepin. Mechanism: unspecified interaction mechanism. Use Caution/Monitor. Use combination with caution.neostigmineneostigmine increases and doxepin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.nilotinibnilotinib will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.norepinephrinedoxepin increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepin increases effects of norepinephrine by unknown mechanism. Use Caution/Monitor.nortriptylinedoxepin and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin and nortriptyline both increase sedation. Use Caution/Monitor.ofloxacindoxepin and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.olanzapineolanzapine and doxepin both increase sedation. Use Caution/Monitor.doxepin and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instancesoliceridinedoxepin, oliceridine. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely.doxepin increases toxicity of oliceridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Anticholinergic drugs may increase risk