Drug reference

Doxepin

TCA · Antidepressant

Also known as Doxepin hydrochloride

TCAAntidepressant

CDSCO approved

EXCRETION

—

not curated

INTERACTIONS

12 major

incl. contraindicated

PREGNANCY

—

not curated

Top interactionssee all 12 →

MoclobemideContraindicatedTextbookG&G 14e
AdrenalineSevereTextbookKDT 7e · p365
ArtemisininsSevereTextbookKDT 7e · p816-835
Meglumine AntimoniateSevereTextbookHarrison 22e · p1740

Mechanism

Doxepin, a tricyclic antidepressant, functions by blocking the re-uptake of both serotonin and noradrenaline in the brain, though to varying degrees. This action increases the concentration of these neurotransmitters in the synaptic cleft, enhancing mood. Doxepin also possesses significant sedative properties, making it particularly useful for agitated and anxious patients.

Indications

Depressive illness (particularly where sedation is required)depressionpsychotic depression (with first-generation antipsychotics)insomnia (low doses)pain conditionsSleep maintenance difficultiesInsomniapruritus control in Atopic Dermatitisimprove sleep in AD patients due to sedation

Dosing

Adult: BY MOUTH: Initially 75 mg daily in divided doses, alternatively 75 mg once daily, adjusted according to response, dose to taken at bedtime; maintenance 25–300 mg daily, doses above 100 mg given in 3 divided doses
Geriatric: Start with lower doses and adjust according to response. Elderly patients are particularly susceptible to many of the side-effects of tricyclic antidepressants; low initial doses should be used, with close monitoring, particularly for psychiatric and cardiac side-effects.
Max dose: 300 mg daily

Pharmacokinetics

Half-life

18 hours (parent), 30 hours (active metabolite)

Metabolism

hepatic (CYP2D6, CYP2C19, CYP3A3/4, CYP1A2)

Contraindications

Acute porphyrias
during manic phase of bipolar disorder

Side effects

Common

AgitationAlopeciaAppetite decreasedAstheniaAsthma exacerbatedBreast enlargementGynaecomastiaHyperhidrosisHypertensionHypotensionIncreased risk of fractureLeucopeniaMood alteredMovement disordersNauseaNervousnessPhotosensitivity reactionSexual dysfunctionSkin reactionsSpeech disorderTesticular hypertrophyTremorUrinary hesitationVomitingWeight changesWithdrawal syndromesedationcognitive dullingblurred visiondry mouthtachycardiaconstipationdifficulty urinatingorthostatic hypotensionweight gainAbnormal thinking and behaviorWorsens suicidal ideation and depressionsedation (can become bothersome)

Serious