Doxepin: Brands, Price & Uses in Bangladesh

Doxepin is a tricyclic antidepressant (TCA) of the dibenzoxepine class with established and evidence-based uses that differ by dose and formulation:

Established/FDA-approved uses

• Major depressive disorder (oral, standard/higher doses) — approved for treatment of depression in adults.
• Anxiety disorders (oral, standard doses) — approved for treatment of anxiety in adults, including anxiety associated with depression, alcohol use disorder, and certain psychophysiologic conditions.
• Insomnia characterized by difficulty with sleep maintenance — a very-low-dose oral formulation of Doxepin (3 mg/6 mg) is specifically FDA-approved for this indication in adults.
• Pruritus associated with atopic dermatitis or lichen simplex chronicus — a topical 5% cream formulation of Doxepin is FDA-approved for short-term relief of itching.

Off-label / adjunctive uses (commonly used, not FDA-approved indications)

• Chronic idiopathic urticaria (as an add-on when antihistamines alone are insufficient) — off-label, based on its potent H1/H2 antihistaminic activity.
• Chronic pain syndromes and neuropathic pain — off-label, extrapolated from TCA class evidence; requires individualized specialist assessment.

The specific indication and dose form must be determined by a physician; the low-dose insomnia formulation and higher-dose antidepressant formulation of Doxepin are not interchangeable.

Dosing of Doxepin is highly dependent on the indication and must be individualized by the prescribing physician. It should be taken exactly as prescribed; do not increase, decrease, stop, or share Doxepin without medical advice.

Depression and Anxiety (oral, standard-dose formulation)

Insomnia — sleep maintenance (low-dose formulation, e.g. 3 mg/6 mg)

• Adults: 6 mg once daily, within 30 minutes of bedtime.
• Elderly (65 years and older): 3 mg once daily to start.
• Should not be taken within 3 hours of a meal, as food can delay onset of effect. A full night (7–8 hours) should remain available for sleep after dosing.

Pruritus (topical 5% cream)

• Apply a thin film to the affected area four times daily, at approximately 3–4 hour intervals, for up to 8 days of continuous use.
• Not recommended for use over large body surface areas due to potential for systemic absorption and sedation.

Renal/Hepatic Impairment

Doxepin is metabolized by the liver; patients with hepatic impairment may require lower doses and slower titration, with clinical monitoring. No well-established formal dose-adjustment schedule exists for renal impairment, but caution and conservative dosing are advised.

Side effects of Doxepin vary with dose and formulation.

Common (more likely at standard/higher antidepressant doses)

• Drowsiness/sedation
• Dry mouth
• Constipation
• Blurred vision
• Dizziness, orthostatic (postural) hypotension
• Weight gain
• Urinary hesitancy

Less common but serious

• Cardiac conduction changes/arrhythmia (risk increases with higher doses, pre-existing cardiac disease, or overdose)
• Confusion, especially in the elderly
• Seizures (rare)
• Worsening of depression or emergence of suicidal thoughts (see Boxed Warning; see Precautions)

Low-dose (insomnia) formulation

At the 3 mg/6 mg insomnia dose, Doxepin is generally well tolerated, with somnolence/sedation and nausea being the most commonly reported effects; anticholinergic and cardiovascular effects are minimal at this dose.

Topical formulation

Local application-site burning, stinging, and drowsiness (from systemic absorption) are the most commonly reported effects with the topical cream form of Doxepin.