of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor for signs of urinary retention or reduced gastric motility if oliceridine is coadministered with anticholinergics.olodaterol inhaleddoxepin and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmiasonabotulinumtoxinAonabotulinumtoxinA and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.ondansetrondoxepin and ondansetron both increase QTc interval. Use Caution/Monitor.opium tinctureopium tincture and doxepin both increase sedation. Use Caution/Monitor.orphenadrinedoxepin and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.orphenadrine and doxepin both increase sedation. Use Caution/Monitor.osilodrostatosilodrostat and doxepin both increase QTc interval. Use Caution/Monitor.oxaliplatindoxepin and oxaliplatin both increase QTc interval. Use Caution/Monitor.oxazepamoxazepam and doxepin both increase sedation. Use Caution/Monitor.oxybutyninoxybutynin and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.oxybutynin topicaloxybutynin topical and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.oxybutynin transdermaloxybutynin transdermal and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.oxycodoneoxycodone and doxepin both increase sedation. Use Caution/Monitor.oxymetazoline intranasaldoxepin increases effects of oxymetazoline intranasal by pharmacodynamic synergism. Use Caution/Monitor. TCAs inhibit norepinephrine uptake in adrenergic neurons, thereby increasing synaptic norepinephrine levels. Coadministration with alpha1 agonists may cause increased adrenergic receptor stimulation. When oxymetazoline is combined with intranasal tetracaine for dental anesthesia, avoid or use alternant anesthetic in patients taking TCAs.oxymorphoneoxymorphone and doxepin both increase sedation. Use Caution/Monitor.paliperidonedoxepin and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely.paliperidone and doxepin both increase sedation. Use Caution/Monitor.pancuroniumpancuronium and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.papaveretumpapaveretum and doxepin both increase sedation. Use Caution/Monitor.papaverinedoxepin and papaverine both increase sedation. Use Caution/Monitor.paroxetinedoxepin and paroxetine both increase QTc interval. Modify Therapy/Monitor Closely.pasireotidedoxepin and pasireotide both increase QTc interval. Use Caution/Monitor.pazopanibdoxepin and pazopanib both increase QTc interval. Use Caution/Monitor.peginterferon alfa 2bpeginterferon alfa 2b, doxepin. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.pentazocinepentazocine and doxepin both increase sedation. Use Caution/Monitor.doxepin and pentazocine both increase serotonin levels. Modify Therapy/Monitor Closely.pentobarbitalpentobarbital and doxepin both increase sedation. Use Caution/Monitor.perphenazineperphenazine and doxepin both increase sedation. Use Caution/Monitor.phendimetrazinedoxepin increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenobarbitalphenobarbital and doxepin both increase sedation. Use Caution/Monitor.phenterminedoxepin increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenylephrinedoxepin increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenylephrine ophthalmicdoxepin, phenylephrine ophthalmic. 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.phenylephrine POdoxepin increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .pholcodinedoxepin and pholcodine both increase sedation. Use Caution/Monitor.physostigminephysostigmine increases and doxepin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.pilocarpinepilocarpine increases and doxepin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.pimavanserindoxepin and pimavanserin both increase QTc interval. Use Caution/Monitor.pimozidepimozide and doxepin both increase sedation. Use Caution/Monitor.pirbuteroldoxepin increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.posaconazoledoxepin and posaconazole both increase QTc interval. Modify Therapy/Monitor Closely.pralidoximepralidoxime and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.pregabalinpregabalin, 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.primidoneprimidone and doxepin both increase sedation. Use Caution/Monitor.prochlorperazineprochlorperazine and doxepin both increase QTc interval. Use Caution/Monitor.prochlorperazine and doxepin both increase sedation. Use Caution/Monitor.promethazinepromethazine and doxepin both increase QTc interval. Use Caution/Monitor.promethazine and doxepin both increase sedation. Use Caution/Monitor.propafenonepropafenone will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.doxepin and propafenone both increase QTc interval. Use Caution/Monitor.propanthelinepropantheline and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.propofolpropofol and doxepin both increase sedation. Use Caution/Monitor.propylhexedrinedoxepin increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.protriptylinedoxepin and protriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin and protriptyline both increase sedation. Use Caution/Monitor.pyridostigminepyridostigmine increases and doxepin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.quazepamquazepam and doxepin both increase sedation. Use Caution/Monitor.quetiapinequetiapine and doxepin both increase sedation. Use Caution/Monitor.doxepin and quetiapine both increase QTc interval. Use Caution/Monitor.ramelteondoxepin and ramelteon both increase sedation. Use Caution/Monitor.doxepin will increase the level or effect of ramelteon by unspecified interaction mechanism. Use Caution/Monitor. AUC and Cmax increased by 66% and 69% respectively.ranolazinedoxepin and ranolazine both increase QTc interval. Modify Therapy/Monitor Closely.rapacuroniumrapacuronium and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.remifentanildoxepin, remifentanil. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. May also increase risk of serotonin syndrome.remimazolamremimazolam, doxepin. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.rifabutinrifabutin decreases levels of doxepin by increasing metabolism. Use Caution/Monitor.rilpivirinedoxepin and rilpivirine both increase QTc interval. Use Caution/Monitor.risperidonedoxepin and risperidone both increase QTc interval. Modify Therapy/Monitor Closely.risperidone and doxepin both increase sedation. Use Caution/Monitor.ritonavirritonavir will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.rivastigminerivastigmine increases and doxepin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.rizatriptanrizatriptan and doxepin both increase serotonin levels. Modify Therapy/Monitor Closely.rocuroniumrocuronium and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.rolapitantrolapitant will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.romidepsindoxepin and romidepsin both increase QTc interval. Modify Therapy/Monitor Closely.salmeteroldoxepin increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.doxepin and salmeterol both increase QTc interval. Use Caution/Monitor.SAMedoxepin and SAMe both increase serotonin levels. Modify Therapy/Monitor Closely.saquinavirdoxepin and saquinavir both increase QTc interval. Use Caution/Monitor.scopolaminescopolamine and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.scullcapdoxepin and scullcap both increase sedation. Use Caution/Monitor.secobarbitalsecobarbital and doxepin both increase sedation. Use Caution/Monitor.selpercatinibdoxepin and selpercatinib both increase QTc interval. Use Caution/Monitor.sevofluranesevoflurane and doxepin both increase sedation. Use Caution/Monitor.doxepin and sevoflurane both increase QTc interval. Use Caution/Monitor.shepherd's pursedoxepin and shepherd's purse both increase sedation. Use Caution/Monitor.siponimoddoxepin and siponimod both increase QTc interval. Use Caution/Monitor.sodium sulfate/?magnesium sulfate/potassium chloridesodium sulfate/?magnesium sulfate/potassium chloride increases effects of doxepin by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of seizures when using higher dose of magnesium sulfate together with drugs that lower the seizure threshold.sodium sulfate/potassium chloride/magnesium sulfate/polyethylene glycoldoxepin, sodium sulfate/potassium chloride/magnesium sulfate/polyethylene glycol. Other (see comment). Use Caution/Monitor. Comment: Caution when bowel preps are used with drugs that cause SIADH or NSAIDs; increased risk for water retention or electrolyte imbalance.sodium sulfate/potassium sulfate/magnesium sulfatesodium sulfate/potassium sulfate/magnesium sulfate increases effects of doxepin by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of seizures when using higher dose of magnesium sulfate together with drugs that lower the seizure threshold.solifenacinsolifenacin and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin and solifenacin both increase QTc interval. Use Caution/Monitor.sorafenibdoxepin and sorafenib both increase QTc interval. Use Caution/Monitor.stiripentolstiripentol, doxepin. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.stiripentol, doxepin. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.succinylcholinesuccinylcholine increases and doxepin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.sufentanilsufentanil and doxepin both increase sedation. Use Caution/Monitor.sufentanil SLsufentanil SL, 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.sulfamethoxazoledoxepin and sulfamethoxazole both increase QTc interval. Modify Therapy/Monitor Closely.sumatriptansumatriptan and doxepin both increase serotonin levels. Modify Therapy/Monitor Closely.sumatriptan intranasalsumatriptan intranasal and doxepin both increase serotonin levels. Modify Therapy/Monitor Closely.sunitinibdoxepin and sunitinib both increase QTc interval. Use Caution/Monitor.suvorexantsuvorexant and doxepin both increase sedation. Modify Therapy/Monitor Closely. Dosage adjustments of suvorexant and concomitant CNS depressants may be necessarytacrolimusdoxepin and tacrolimus both increase QTc interval. Use Caution/Monitor.tapentadoltapentadol and doxepin both increase sedation. Use Caution/Monitor.doxepin and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.telavancindoxepin and telavancin both increase QTc interval. Modify Therapy/Monitor Closely.temazepamtemazepam and doxepin both increase sedation. Use Caution/Monitor.terbinafineterbinafine will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.terbutalinedoxepin increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.teriflunomideteriflunomide decreases levels of doxepin by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.tetrabenazinetetrabenazine and doxepin both increase QTc interval. Use Caution/Monitor.thioridazinethioridazine and doxepin both increase sedation. Use Caution/Monitor.thiothixenethiothixene and doxepin both increase sedation. Use Caution/Monitor.doxepin and thiothixene both increase QTc interval. Use Caution/Monitor.thyroid desiccatedthyroid desiccated increases effects of doxepin by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.tiotropiumtiotropium and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.tolterodinetolterodine and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.topiramatedoxepin and topiramate both increase sedation. Modify Therapy/Monitor Closely.tramadoltramadol and doxepin both increase sedation. Use Caution/Monitor.doxepin and tramadol both increase serotonin levels. Modify Therapy/Monitor Closely.trazodonedoxepin and trazodone both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin and trazodone both increase sedation. Use Caution/Monitor.triazolamtriazolam and doxepin both increase sedation. Use Caution/Monitor.triclabendazoledoxepin and triclabendazole both increase QTc interval. Use Caution/Monitor.triclofostriclofos and doxepin both increase sedation. Use Caution/Monitor.trifluoperazinetrifluoperazine and doxepin both increase sedation. Use Caution/Monitor.trihexyphenidyltrihexyphenidyl and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor. Potential for additive anticholinergic effects.trimethoprimdoxepin and trimethoprim both increase QTc interval. Modify Therapy/Monitor Closely.trimipraminedoxepin and trimipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepin and trimipramine both increase sedation. Use Caution/Monitor.triprolidinetriprolidine and doxepin both increase sedation. Use Caution/Monitor.triptorelindoxepin and triptorelin both increase QTc interval. Use Caution/Monitor.tropisetrondoxepin and tropisetron both increase QTc interval. Modify Therapy/Monitor Closely.trospium chloridetrospium chloride and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.umeclidinium bromide/vilanterol inhaleddoxepin and umeclidinium bromide/vilanterol inhaled both decrease QTc interval. Use Caution/Monitor.valbenazinevalbenazine and doxepin both increase QTc interval. Use Caution/Monitor.valerianvalerian and doxepin both increase sedation. Use Caution/Monitor.vardenafildoxepin and vardenafil both increase QTc interval. Use Caution/Monitor.vecuroniumvecuronium and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.vemurafenibdoxepin and vemurafenib both increase QTc interval. Use Caution/Monitor.venlafaxinedoxepin and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.voclosporindoxepin and voclosporin both increase QTc interval. Use Caution/Monitor.voriconazoledoxepin and voriconazole both increase QTc interval. Modify Therapy/Monitor Closely.vorinostatdoxepin and vorinostat both increase QTc interval. Use Caution/Monitor.xylometazolinedoxepin increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.yohimbinedoxepin increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.ziconotidedoxepin and ziconotide both increase sedation. Use Caution/Monitor.ziprasidoneziprasidone and doxepin both increase sedation. Use Caution/Monitor.zolmitriptanzolmitriptan and doxepin both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (81)acarbosedoxepin increases effects of acarbose by pharmacodynamic synergism. Minor/Significance Unknown.amobarbitalamobarbital, doxepin. 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.atropinedoxepin increases levels of atropine by unknown mechanism. Minor/Significance Unknown.atropine IV/IMdoxepin increases levels of atropine IV/IM by unknown mechanism. Minor/Significance Unknown.bazedoxifene/conjugated estrogensbazedoxifene/conjugated estrogens, doxepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.brimonidinedoxepin decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.butabarbitalbutabarbital, doxepin. 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.butalbitalbutalbital, doxepin. 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.carbamazepinecarbamazepine decreases levels of doxepin by increasing metabolism. Minor/Significance Unknown.chlorpromazinedoxepin, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.doxepin, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.chlorpropamidedoxepin increases effects of chlorpropamide by pharmacodynamic synergism. Minor/Significance Unknown.conjugated estrogensconjugated estrogens, doxepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing