Antidepressant drugs cause a variety of sexual side-effects. Painful ejaculation is a rarely reported side-effect of antidepressants, especially the newer drugs.

A 59-year-old man with recurrent depression had normal sexual function while euthymic and mild decrease in libido while depressed. Although his previous episode of depression responded well to fluoxetine he was not keen on trying it again because of fluoxetine-associated diarrhoea. During a depressive relapse he was treated with venlafaxine 75 mg daily which was later increased to 150 mg daily. The antidepressant response was good. Unfortunately, he developed painful ejaculation. It was sharp and burning in nature and located deep in the shaft of the penis. It would begin just before ejaculation and lasted until the penis became flaccid. This was so unpleasant that it not only interfered with the pleasure of intercourse, but also led him to avoid sexual intercourse. The pain persisted despite reducing the dose of venlafaxine to 75 mg. When venlafaxine was stopped the pain disappeared. Later, he made a good recovery on citalopram 40 mg daily. He denied experiencing pain or any other sexual side-effects and also denied having ever previously experienced painful ejaculation.

This is the first report of venlafaxine-induced painful ejaculation. Painful ejaculation/orgasm have been reported with various tricyclic antidepressants (Reference Kulik and WilburKulik & Wilbur, 1982; Reference Aizenberg, Zemishlany and HermeshAizenberg et al, 1991). Some of the people in question improved with dosage reduction or after changing to other tricyclics, but others improved only when they stopped the medication. Hsu & Shen (Reference Hsu and Shen1995) reported a case of fluoxetine-induced painful ejaculation that improved when the dosage was reduced from 20 mg daily to 20 mg on alternate days. Thus, painful ejaculation, when it occurs, could be a dose-dependent side-effect in some individuals. It has been suggested that partial blockade of peripheral sympathetic adrenergic receptors could interfere with coordinated contractions of smooth muscles involved in semen transport and thus induce painful spasms or retrograde ejaculation (Reference Kulik and WilburKulik & Wilbur, 1982). However, venlafaxine has little if any adrenoceptor-blocking action. Thus, the mechanism of antidepressant drug-induced painful ejaculation remains elusive.

Sexual side-effects of antidepressant drugs cause distress, strain relationships, impair quality of life and reduce compliance with treatment. Enquiring routinely about side-effects, especially sexual side-effects, of antidepressants would help to improve compliance with treatment.