doxepin hydrochloride: clinical use

Prescribing considerations

• Licensed for depressive illness in adults, especially where sedation is required; not licensed by the selected product solely as a hypnotic.
• Assess suicide and overdose risk and monitor mood closely after initiation and treatment changes.
• Review anticholinergic burden, falls risk, postural hypotension and confusion, particularly in older adults.
• Use caution with cardiovascular disease, recent myocardial infarction, conduction disorders, epilepsy, and renal or hepatic impairment.
• Review interacting medicines, alcohol use and planned anaesthesia or dental procedures.
• Avoid abrupt cessation because withdrawal symptoms can occur.

Contraindications and cautions

• Hypersensitivity to doxepin, another tricyclic antidepressant or a product excipient
• Mania
• Severe liver disease
• Glaucoma
• Tendency to urinary retention
• Breastfeeding

Monitoring

• Clinical response and suicidal thoughts or behaviour
• Sedation, cognition, anticholinergic effects, postural symptoms and falls risk
• Blood pressure, pulse and cardiac status where clinically indicated
• Seizure control in susceptible patients
• Hepatic and renal status where impairment is present
• Adherence, adverse effects and withdrawal symptoms during discontinuation

Clinical pharmacology

Doxepin is a non-selective monoamine reuptake inhibitor with prominent antihistaminic and antimuscarinic activity. Hepatic first-pass metabolism, including CYP2D6 metabolism, produces active desmethyldoxepin; both may persist and contribute to effects.

Formulation and product differences

• The selected product is a hard oral capsule containing lactose.
• The capsule must be swallowed whole and not crushed or chewed.
• Excipients, appearance, packaging and storage requirements may differ between manufacturers; check the supplied product information.

Capsule

Route: Oral

Strengths: 10 mg, 25 mg, 50 mg