This is a centrally acting anti-hypertensive drug. Indications: moderate to severe hypertension in conjunction with a diuretic; pregnancy-induced hypertension.

Cautions: positive direct Coomb's test in 20% of patients; interference with laboratory tests; reduce initial dose in renal impairment; blood counts and liver function tests advised.

Contra-indications: history of depression; liver disease, phaeochromocytoma, porphyria.

Side Effects: gastrointestinal disturbances; dry mouth; stomatitis, sialdenitis, bradycardia, exacerbation of angina, postural hypotension, edema, sedation, depression, dizziness, myalgia, nightmares, abnormal liver function tests, hepatitis, jaundice, pancreatitis, haemolytic anemia, leucopenia, thrombocytopenia, eosinophilia, nasal congestion, sexual dysfunction, amenorrhea, hyperprolactinemia.

Dose: by mouth, 250 mg 3 times daily gradually increased; max. dose 3 g daily; In elderly, 125 mg 2 times daily increased to max. of 2 gm daily.