Prophylaxis of hypotension during anaesthesia
Adult: 10-15 mg shortly before or with spinal anaesthesia. Up to 20 mg may be required at high levels of anaesthesia. About 15 min should elapse before repeating a dose.
Adult: As hydrochloride: Moderate hypotension: 5-10 mg.
Adult: As hydrochloride: Emergency: 3-5 mg by slow inj. May be supplemented by IM inj for a more prolonged effect. About 15 min should elapse before repeating a dose.
Paroxysmal supraventricular tachycardia
Adult: As hydrochloride: 10 mg by slow inj over 3-5 min.