BMA Concise Guide to Medicine & Drugs

Dosulepin (Dothiepin)

Brand name Prothiaden

Used in the following combined preparations None


Drug group Tricyclic antidepressant drug

Overdose danger rating High

Dependence rating Low

Prescription needed Yes

Available as generic Yes


Dosulepin belongs to the tricyclic class of antidepressant drugs, and is used in the long-term treatment of depression. The drug is particularly useful when the depression is accompanied by anxiety and insomnia. Dosulepin elevates mood, increases physical activity, improves appetite, and restores interest in everyday activities. Taken at night, dosulepin encourages sleep and helps eliminate the need for additional sleeping drugs.

Dosulepin takes several weeks to achieve its full antidepressant effect. It has adverse effects common to all tricyclics, including a risk of dangerous heart rhythms, seizures, and coma, if taken in overdose. The drug should not be taken by anyone with a serious heart condition.


Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, capsules.

Frequency and timing of doses 2–3 x daily or once at night.

Adult dosage range 75–150mg daily (a maximum dose of up to 225mg may be given in some circumstances).

Onset of effect Full antidepressant effect may not be felt for 2–6 weeks, but adverse effects may be noticed within a day or two.

Duration of action Several days.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug Do not stop taking the drug without consulting your doctor, who may supervise a gradual reduction in dosage. Abrupt cessation of the drug may cause withdrawal symptoms and a recurrence of the original problem.


Seek immediate medical advice in all cases. Take emergency action if palpitations or loss of consciousness occur.


The adverse effects of dosulepin are mainly the result of its anticholinergic action. They include drowsiness, dry mouth, sweating, and blurred vision and are more common in the early days of treatment. The drug can also affect normal heart rhythm. If dizziness or fainting occur, consult your doctor. If you have difficulty in passing urine or palpitations, you should stop taking the drug and consult your doctor urgently.


Antiarrhythmic drugs Dosulepin should be avoided in patients on amiodarone, sotalol, and other medications that can affect heart rhythms.

Monoamine oxidase inhibitors (MAOIs) In the rare cases where these drugs are given with dosulepin, serious interactions may occur.

Sedatives All drugs that have a sedative effect on the central nervous system increase the sedative properties of dosulepin.

Antiepileptic drugs Dosulepin may reduce the effectiveness of these drugs.


Be sure to tell your doctor if:

· You have heart problems.

· You have had epileptic seizures.

· You have long-term liver or kidney problems.

· You have glaucoma.

· You have had mania or a psychotic illness.

· You are taking other medicines.

Pregnancy Safety in pregnancy not established. Discuss with your doctor.

Breast-feeding The drug passes into the breast milk, but effects on the baby are unlikely. Discuss with your doctor.

Infants and children Not recommended.

Over 60 Greater risk of adverse effects. Reduced dose necessary.

Driving and hazardous work Avoid such activities until you have learned how dosulepin affects you because the drug can reduce alertness and may cause blurred vision, dizziness, and drowsiness.

Alcohol Avoid. Alcohol may increase the sedative effects of this drug.

Surgery and general anaesthetics Treatment with dosulepin may need to be stopped before you have a general anaesthetic. Discuss this with your doctor or dentist before any operation.


No problems expected.