200-300 mg divided into 1 or 2 intakes (100 mg in the morning & 100 mg or 200 mg at bedtime). Threatened abortion
200-400 mg daily until 12th wk of pregnancy. Menace of preterm delivery
400 mg 6-8 hrly during the acute phase depending on the clinical response, then 200 mg tds as maintenance treatment until 36th wk of pregnancy. Hormone replacement therapy in post-menopausal women receiving estrogen therapy
Continuously or sequentially for at least 12 days/mth.