Tricyclic antidepressant

Dosulepin hydrochloride

Brand names: Prothiaden

Adult dose

Dose: 75mg OD nocte; up to 150mg/day in divided doses

Route: Oral

Frequency: OD–TDS

Clinical pearls

NICE NG222 depression: NOT recommended for initiation due to high fatality in overdose vs benefit; legacy patients only
MHRA Drug Safety Update: prescribing only by specialist if other antidepressants unsuitable, lowest effective dose, smallest pack size
DVLA: warn about driving impairment

Contraindications

Recent MI
Heart block / arrhythmias
Mania
Severe liver disease
Concurrent or recent MAOI
Hypersensitivity

Side effects

Anticholinergic effects (dry mouth, constipation, urinary retention, blurred vision)
Sedation
Postural hypotension
Cardiac toxicity (QT prolongation, arrhythmia in overdose — high fatality)
Weight gain
Sexual dysfunction

Interactions

MAOIs (serotonin syndrome — washout 14 days)
SSRIs/SNRIs
Antipsychotics
Anticholinergics
CYP2D6 inhibitors
QT-prolonging drugs

Monitoring

Mental state
Suicidality
ECG (cardiac risk)
Weight
BP

Reference: BNF; NICE NG222; MHRA Drug Safety Update; https://bnf.nice.org.uk/drugs/dosulepin-hydrochloride/. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

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Pathways