Prazosin

Prazosin hydrochloride was not teratogenic in rats and rabbits.

Although no teratogenic effects were seen in animal testing, the safety of prazosin during pregnancy has not yet been established. The use of prazosin and a beta-blocker for the control of severe hypertension in 44 pregnant women revealed no drug-related foetal abnormalities or adverse effects. Therapy with prazosin was continued for as long as 14 weeks. No foetal or neonatal abnormalities have been reported with the use of prazosin hydrochloride.

Prazosin has also been used alone or in combination with other hypotensive agents in severe hypertension of pregnancy.

Prazosin should be used only when, in the opinion of the physician, potential benefit outweighs potential risk.

Prazosin has been shown to be excreted in small amounts in human milk. Caution should be exercised when prazosin is administered to nursing mothers.

Fertility

A decrease in fertility in male and female rats treated with prazosin hydrochloride was observed at high non-clinically relevant doses (225 times the usual maximum recommended human dose). However no adverse effects were observed at doses up to 75 times the usual maximum recommended human dose.

When instituting therapy with any effective antihypertensive agent, the patient should be advised on how to avoid symptoms resulting from postural hypotension and what measures to take should they develop. The patient should be cautioned to avoid situations where injury could result should dizziness or weakness occur during the initiation of prazosin therapy (i.e. driving or operating machinery).