increase serotonin levels. Use Caution/Monitor.dexmedetomidinedexmedetomidine and mirtazapine both increase sedation. Use Caution/Monitor.dexmethylphenidatemirtazapine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dextroamphetaminemirtazapine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dextroamphetamine and mirtazapine both increase serotonin levels. Use Caution/Monitor.dextroamphetamine transdermalmirtazapine, dextroamphetamine transdermal. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely. Initiate with lower doses and monitor for signs and symptoms of serotonin syndrome, particularly during initiation or dosage increase. If serotonin syndrome occurs, discontinue dextroamphetamine transdermal and concomitant serotonergic drug(s).dextromethorphandextromethorphan and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.dextromoramidedextromoramide and mirtazapine both increase sedation. Use Caution/Monitor.diamorphinediamorphine and mirtazapine both increase sedation. Use Caution/Monitor.diazepamdiazepam and mirtazapine both increase sedation. Use Caution/Monitor.diazepam intranasaldiazepam intranasal, mirtazapine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.diethylpropionmirtazapine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.difelikefalindifelikefalin and mirtazapine both increase sedation. Use Caution/Monitor.difenoxin hcldifenoxin hcl and mirtazapine both increase sedation. Use Caution/Monitor.dihydroergotaminedihydroergotamine and mirtazapine both increase serotonin levels. Use Caution/Monitor.dihydroergotamine intranasaldihydroergotamine intranasal and mirtazapine both increase serotonin levels. Use Caution/Monitor.dimenhydrinatedimenhydrinate and mirtazapine both increase sedation. Use Caution/Monitor.diphenhydraminediphenhydramine and mirtazapine both increase sedation. Use Caution/Monitor.diphenoxylate hcldiphenoxylate hcl and mirtazapine both increase sedation. Use Caution/Monitor.dipipanonedipipanone and mirtazapine both increase sedation. Use Caution/Monitor.dobutaminemirtazapine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dolasetrondolasetron and mirtazapine both increase QTc interval. Use Caution/Monitor.donepezildonepezil and mirtazapine both increase QTc interval. Use Caution/Monitor.dopaminemirtazapine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dopexaminemirtazapine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepindoxepin and mirtazapine both increase sedation. Use Caution/Monitor.doxepin and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.doxylaminedoxylamine and mirtazapine both increase sedation. Use Caution/Monitor.droperidoldroperidol and mirtazapine both increase sedation. Use Caution/Monitor.duloxetineduloxetine and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.duvelisibduvelisib will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.efavirenzefavirenz will decrease the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.efavirenz and mirtazapine both increase QTc interval. Use Caution/Monitor.elagolixelagolix decreases levels of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.eletriptaneletriptan and mirtazapine both increase serotonin levels. Use Caution/Monitor.eliglustateliglustat increases levels of mirtazapine 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.elvitegravir/cobicistat/emtricitabine/tenofovir DFelvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of mirtazapine 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.encorafenibencorafenib, mirtazapine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.enzalutamideenzalutamide will decrease the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ephedrinemirtazapine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.epinephrinemirtazapine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.epinephrine racemicmirtazapine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.ergotamineergotamine and mirtazapine both increase serotonin levels. Use Caution/Monitor.escitalopramescitalopram and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.estazolamestazolam and mirtazapine both increase sedation. Use Caution/Monitor.ethanolethanol and mirtazapine both increase sedation. Use Caution/Monitor.etomidateetomidate and mirtazapine both increase sedation. Use Caution/Monitor.etravirineetravirine will decrease the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fedratinibfedratinib will increase the level or effect of mirtazapine 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 mirtazapine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.fenfluraminemirtazapine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.fenfluramine, mirtazapine. 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.fexinidazolefexinidazole will increase the level or effect of mirtazapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.finerenonemirtazapine 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 weak CYP3A4 inhibitors. Adjust finererone dosage as needed.fingolimodfingolimod and mirtazapine both increase QTc interval. Use Caution/Monitor.flibanserinmirtazapine 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.fluoxetinefluoxetine and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.fluphenazinefluphenazine and mirtazapine both increase sedation. Use Caution/Monitor.flurazepamflurazepam and mirtazapine both increase sedation. Use Caution/Monitor.fluvoxaminefluvoxamine and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.formoterolmirtazapine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.fosamprenavirfosamprenavir increases levels of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .fosphenytoinfosphenytoin will decrease the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fostemsavirmirtazapine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. frovatriptanfrovatriptan and mirtazapine both increase serotonin levels. Use Caution/Monitor.gabapentingabapentin, mirtazapine. 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, mirtazapine. 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.ganaxolonemirtazapine and ganaxolone both increase sedation. Use Caution/Monitor.gemifloxacingemifloxacin and mirtazapine both increase QTc interval. Use Caution/Monitor.gemtuzumabmirtazapine and gemtuzumab both increase QTc interval. Use Caution/Monitor.gilteritinibgilteritinib and mirtazapine both increase QTc interval. Use Caution/Monitor.goserelinmirtazapine and goserelin both increase QTc interval. Use Caution/Monitor.granisetrongranisetron and mirtazapine both increase QTc interval. Use Caution/Monitor.haloperidolhaloperidol and mirtazapine both increase sedation. Use Caution/Monitor.mirtazapine and haloperidol both increase QTc interval. Use Caution/Monitor.histrelinmirtazapine and histrelin both increase QTc interval. Use Caution/Monitor.hydrocodonehydrocodone, mirtazapine. 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 mirtazapine both increase sedation. Use Caution/Monitor.hydroxyzinehydroxyzine and mirtazapine both increase sedation. Use Caution/Monitor.hydroxyzine and mirtazapine both increase QTc interval. Use Caution/Monitor.iloperidoneiloperidone and mirtazapine both increase sedation. Use Caution/Monitor.iloperidone increases levels of mirtazapine 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.imipramineimipramine and mirtazapine both increase sedation. Use Caution/Monitor.imipramine and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.indinavirindinavir will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.isavuconazonium sulfatemirtazapine will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.isoniazidisoniazid and mirtazapine both increase serotonin levels. Use Caution/Monitor.isoproterenolmirtazapine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.istradefyllineistradefylline will increase the level or effect of mirtazapine 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 will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.itraconazole and mirtazapine both increase QTc interval. Use Caution/Monitor.ketamineketamine and mirtazapine both increase sedation. Use Caution/Monitor.ketoconazoleketoconazole will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce mirtazapine dose if coadministration of strong CYP3A4 inhibitor is necessary. Once CYP3A4 inhibitor is discontinued, consider increasing mirtazapine dose.ketotifen, ophthalmicketotifen, ophthalmic and mirtazapine both increase sedation. Use Caution/Monitor.L-tryptophanL-tryptophan and mirtazapine both increase serotonin levels. Use Caution/Monitor.lapatinibmirtazapine and lapatinib both increase QTc interval. Use Caution/Monitor.lasmiditanlasmiditan, mirtazapine. 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.lemborexantmirtazapine 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.lemborexant, mirtazapine. 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.lenacapavirlenacapavir will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.letermovirletermovir increases levels of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.leuprolidemirtazapine and leuprolide both increase QTc interval. Use Caution/Monitor.levalbuterolmirtazapine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.levofloxacinmirtazapine and levofloxacin both increase QTc interval. Use Caution/Monitor.levoketoconazolelevoketoconazole will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce mirtazapine dose if coadministration of strong CYP3A4 inhibitor is necessary. Once CYP3A4 inhibitor is discontinued, consider increasing mirtazapine dose.levomilnacipranlevomilnacipran and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.levorphanollevorphanol and mirtazapine both increase sedation. Use Caution/Monitor.lisdexamfetaminemirtazapine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lithiumlithium and mirtazapine both increase serotonin levels. Use Caution/Monitor.lofepraminelofepramine and mirtazapine both increase sedation. Use Caution/Monitor.lofepramine and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.lofexidinelofexidine and mirtazapine both increase sedation. Use Caution/Monitor.mirtazapine and lofexidine both increase QTc interval. Use Caution/Monitor.lomitapidemirtazapine increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.loperamidemirtazapine and loperamide both increase QTc interval. Use Caution/Monitor.lopinavirlopinavir increases levels of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity.loprazolamloprazolam and mirtazapine both increase sedation. Use Caution/Monitor.lorazepamlorazepam and mirtazapine both increase sedation. Use Caution/Monitor.lorcaserinlorcaserin will increase the level or effect of mirtazapine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.lorlatiniblorlatinib will decrease the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.lormetazepamlormetazepam and mirtazapine both increase sedation. Use Caution/Monitor.loxapineloxapine and mirtazapine both increase sedation. Use Caution/Monitor.loxapine inhaledloxapine inhaled and mirtazapine both increase sedation. Use Caution/Monitor.lsdlsd and mirtazapine both increase serotonin levels. Use Caution/Monitor.lurasidonelurasidone increases effects of mirtazapine by Other (see comment). Use Caution/Monitor. Comment: Potential for additive CNS effects .maprotilinemaprotiline and mirtazapine both increase sedation. Use Caution/Monitor.maprotiline and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.maravirocmaraviroc, mirtazapine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of orthostatic hypotension.marijuanamarijuana and mirtazapine both increase sedation. Use Caution/Monitor.melatoninmelatonin and mirtazapine both increase sedation. Use Caution/Monitor.meperidinemeperidine and mirtazapine both increase sedation. Use Caution/Monitor.meperidine and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.meprobamatemeprobamate and mirtazapine both increase sedation. Use Caution/Monitor.metaproterenolmirtazapine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.metaxalonemetaxalone and mirtazapine both increase sedation. Use Caution/Monitor.methadonemethadone and mirtazapine both increase sedation. Use Caution/Monitor.methamphetaminemirtazapine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methocarbamolmethocarbamol and mirtazapine both increase sedation. Use Caution/Monitor.methylenedioxymethamphetaminemirtazapine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.midazolammidazolam and mirtazapine both increase sedation. Use Caution/Monitor.midazolam intranasalmirtazapine will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal