QTc interval. Avoid or Use Alternate Drug.buprenorphine subdermal implantMonitor Closely (1)nortriptyline, buprenorphine subdermal implant. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.Serious - Use Alternative (2)buprenorphine subdermal implant and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug. buprenorphine subdermal implant and nortriptyline both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatebuprenorphine transdermalSerious - Use Alternative (2)buprenorphine transdermal and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug. buprenorphine transdermal and nortriptyline both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatebuprenorphine, long-acting injectionMonitor Closely (1)nortriptyline, buprenorphine, long-acting injection. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.Serious - Use Alternative (2)buprenorphine, long-acting injection and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug. buprenorphine, long-acting injection and nortriptyline both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatebupropionMonitor Closely (2)bupropion will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. nortriptyline increases toxicity of bupropion by unspecified interaction mechanism. Use Caution/Monitor. May lower seizure threshold; keep bupropion dose as low as possible.buspironeSerious - Use Alternative (1)nortriptyline and buspirone both increase serotonin levels. Avoid or Use Alternate Drug.butabarbitalMonitor Closely (1)butabarbital and nortriptyline both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, 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.butalbitalMonitor Closely (1)butalbital and nortriptyline both increase sedation. Use Caution/Monitor.Minor (1)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.butorphanolMonitor Closely (1)butorphanol and nortriptyline both increase sedation. Use Caution/Monitor.caffeineMonitor Closely (1)nortriptyline increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.calcium/magnesium/potassium/sodium oxybatesSerious - Use Alternative (1)nortriptyline, 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.carbacholMonitor Closely (1)carbachol increases and nortriptyline decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.carbamazepineMinor (1)carbamazepine decreases levels of nortriptyline by increasing metabolism. Minor/Significance Unknown.carbinoxamineMonitor Closely (1)carbinoxamine and nortriptyline both increase sedation. Use Caution/Monitor.carisoprodolMonitor Closely (1)carisoprodol and nortriptyline both increase sedation. Use Caution/Monitor.celecoxibMonitor Closely (1)celecoxib will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cenobamateMonitor Closely (1)cenobamate, nortriptyline. Either increases effects of the other by sedation. Use Caution/Monitor.ceritinibMonitor Closely (1)ceritinib and nortriptyline both increase QTc interval. Use Caution/Monitor.cevimelineMonitor Closely (1)cevimeline increases and nortriptyline decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.chloral hydrateMonitor Closely (1)chloral hydrate and nortriptyline both increase sedation. Use Caution/Monitor.chlordiazepoxideMonitor Closely (1)chlordiazepoxide and nortriptyline both increase sedation. Use Caution/Monitor.chloroquineMonitor Closely (2)chloroquine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. chloroquine increases toxicity of nortriptyline by QTc interval. Use Caution/Monitor.chlorpheniramineMonitor Closely (1)chlorpheniramine and nortriptyline both increase sedation. Use Caution/Monitor.chlorpromazineMonitor Closely (1)chlorpromazine and nortriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)nortriptyline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects. nortriptyline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.chlorpropamideMinor (1)nortriptyline increases effects of chlorpropamide by pharmacodynamic synergism. Minor/Significance Unknown.chlorzoxazoneMonitor Closely (1)chlorzoxazone and nortriptyline both increase sedation. Use Caution/Monitor.cimetidineMonitor Closely (1)cimetidine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cinnarizineMonitor Closely (1)cinnarizine and nortriptyline both increase sedation. Use Caution/Monitor.cisatracuriumMonitor Closely (1)cisatracurium and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.citalopramSerious - Use Alternative (2)citalopram and nortriptyline both increase serotonin levels. Avoid or Use Alternate Drug. Citalopram may increase TCA levels. Increased risk of serotonin syndrome or neuroleptic malignant syndrome. Potential risk for QT prolongation. ECG monitoring is recommended. citalopram and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug.clarithromycinSerious - Use Alternative (1)nortriptyline and clarithromycin both increase QTc interval. Avoid or Use Alternate Drug.clemastineMonitor Closely (1)clemastine and nortriptyline both increase sedation. Use Caution/Monitor.clobazamMonitor Closely (2)clobazam will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly. nortriptyline, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).clomipramineMonitor Closely (2)clomipramine and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor. clomipramine and nortriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (2)clomipramine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug. clomipramine and nortriptyline both increase serotonin levels. Avoid or Use Alternate Drug.clonazepamMonitor Closely (1)clonazepam and nortriptyline both increase sedation. Use Caution/Monitor.clonidineSerious - Use Alternative (1)nortriptyline decreases effects of clonidine by Other (see comment). Avoid or Use Alternate Drug. Comment: Inhibition of uptake by adrenergic neurons.clorazepateMonitor Closely (1)clorazepate and nortriptyline both increase sedation. Use Caution/Monitor.clozapineMonitor Closely (2)clozapine and nortriptyline both increase QTc interval. Use Caution/Monitor. clozapine and nortriptyline both increase sedation. Use Caution/Monitor.cobicistatMonitor Closely (1)cobicistat will increase the level or effect of nortriptyline by Other (see comment). Use Caution/Monitor. Carefully titrate dose of the antidepressant to the desired effect, including using the lowest feasible initial or maintenance dose, and monitor its response during coadministration with TCAs and cobicistat. cocaine topicalMonitor Closely (1)nortriptyline and cocaine topical both increase serotonin levels. Modify Therapy/Monitor Closely.codeineMonitor Closely (1)codeine and nortriptyline both increase sedation. Use Caution/Monitor.conjugated estrogensMinor (1)conjugated estrogens, nortriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.conjugated estrogens, vaginalMinor (1)conjugated estrogens, vaginal, nortriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.crizotinibMonitor Closely (1)crizotinib and nortriptyline both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.cyclizineMonitor Closely (2)cyclizine and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor. cyclizine and nortriptyline both increase sedation. Use Caution/Monitor.cyclobenzaprineMonitor Closely (2)cyclobenzaprine and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor. cyclobenzaprine and nortriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)nortriptyline and cyclobenzaprine both increase serotonin levels. Avoid or Use Alternate Drug.cyclosporineMonitor Closely (1)cyclosporine will increase the level or effect of nortriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.cyproheptadineMonitor Closely (1)cyproheptadine and nortriptyline both increase sedation. Use Caution/Monitor.dacomitinibSerious - Use Alternative (1)dacomitinib will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities. dantroleneMonitor Closely (1)dantrolene and nortriptyline both increase sedation. Use Caution/Monitor.daridorexantMonitor Closely (1)nortriptyline 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. darifenacinMonitor Closely (2)darifenacin will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. darifenacin and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.dasatinibMonitor Closely (1)nortriptyline and dasatinib both increase QTc interval. Modify Therapy/Monitor Closely.debrisoquineMonitor Closely (1)nortriptyline decreases effects of debrisoquine by Other (see comment). Use Caution/Monitor. Comment: Inhibition of uptake by adrenergic neurons.degarelixMonitor Closely (1)degarelix and nortriptyline both increase QTc interval. Use Caution/Monitor.desfluraneMonitor Closely (2)desflurane and nortriptyline both increase QTc interval. Use Caution/Monitor. desflurane and nortriptyline both increase sedation. Use Caution/Monitor.Minor (1)desflurane, nortriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Risk of arrhythmias or hypotension.desipramineMonitor Closely (2)desipramine and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor. desipramine and nortriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (2)desipramine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug. desipramine and nortriptyline both increase serotonin levels. Avoid or Use Alternate Drug.desvenlafaxineMonitor Closely (1)desvenlafaxine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mgSerious - Use Alternative (1)nortriptyline and desvenlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.deutetrabenazineMonitor Closely (2)nortriptyline and deutetrabenazine both increase sedation. Use Caution/Monitor. deutetrabenazine and nortriptyline both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).dexchlorpheniramineMonitor Closely (1)dexchlorpheniramine and nortriptyline both increase sedation. Use Caution/Monitor.dexfenfluramineMonitor Closely (2)nortriptyline and dexfenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely. nortriptyline increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)nortriptyline, dexfenfluramine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.dexmedetomidineMonitor Closely (1)dexmedetomidine and nortriptyline both increase sedation. Use Caution/Monitor.dexmethylphenidateMonitor Closely (1)nortriptyline increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)nortriptyline, dexmethylphenidate. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.Minor (1)dexmethylphenidate increases effects of nortriptyline by decreasing metabolism. Minor/Significance Unknown.dextroamphetamineMonitor Closely (3)nortriptyline increases effects of dextroamphetamine by unknown mechanism. Use Caution/Monitor. nortriptyline and dextroamphetamine both increase serotonin levels. Modify Therapy/Monitor Closely. nortriptyline increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)nortriptyline, dextroamphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.dextroamphetamine transdermalMonitor Closely (1)nortriptyline 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.dextromethorphanSerious - Use Alternative (1)nortriptyline and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.dextromoramideMonitor Closely (1)dextromoramide and nortriptyline both increase sedation. Use Caution/Monitor.diamorphineMonitor Closely (1)diamorphine and nortriptyline both increase sedation. Use Caution/Monitor.diazepamMonitor Closely (1)diazepam and nortriptyline both increase sedation. Use Caution/Monitor.diazepam intranasalMonitor Closely (1)diazepam intranasal, nortriptyline. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.dicyclomineMonitor Closely (1)dicyclomine and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.diethylpropionMonitor Closely (1)nortriptyline increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)nortriptyline, diethylpropion. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.difelikefalinMonitor Closely (1)difelikefalin and nortriptyline both increase sedation. Use Caution/Monitor.difenoxin hclMonitor Closely (1)difenoxin hcl and nortriptyline both increase sedation. Use Caution/Monitor.dihydroergotamineMonitor Closely (1)nortriptyline and dihydroergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.dihydroergotamine intranasalMonitor Closely (1)nortriptyline and dihydroergotamine intranasal both increase serotonin levels. Modify Therapy/Monitor Closely.dimenhydrinateMonitor Closely (1)dimenhydrinate and nortriptyline both increase sedation. Use Caution/Monitor.diphenhydramineMonitor Closely (3)diphenhydramine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. diphenhydramine and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.