Dosulepin (INN), formerly known as dothiepin (BAN), is a tricyclic antidepressant (TCA). It is sold under the brand names Prothiaden, Dothep, Thaden and Dopress. Dosulepin blocks the reuptake of serotonin and norepinephrine in the brain, thereby increasing their levels. It is believed that this action is responsible for its mood-elevating effects.

Dosulepin is relatively mild and is used for low-level anxiety, depression and similar disorders, as well as the treatment of chronic and ongoing pain disorders, particularly where insomnia and/or loss of appetite are present. It can take between two and four weeks of regular usage to become effective; it is often started at a low level and the dosage increased if this is ineffective. The drug causes drowsiness as a side-effect, and this may be used as part of the treatment, since anxiety-depressive patients may have difficulty sleeping. The drug is also an effective preventative for migraine.

Adults: Initially 75 mg/day in divided doses or as a single dose at night, increasing to 150 mg/day. In certain circumstances, e.g. in hospital use or unresponsive patients, dosages up to 300 mg daily have been used.