Indications 

• Long-term treatment of circulatory disorders affecting the coronary arteries (ischaemic heart disease)
• Prevention of attacks of angina (heart pain)
• Follow-up treatment of heart attack when symptoms of angina persist 
• High blood pressure in the lung circulation (pulmonary hypertention)
• Treatment of severe weakness of heart muscle (cronic cardiac failure), in combination with cardiac glycosides and/or diuretics. 

Dosage
Unless otherwise prescribed, 40 mg once daily, or 20 mg twice daily. In exceptional cases, the dose may be increased to 40 mg twice daily. In order to obtain the full effect of the drug, when a daily dose of 40 mg twice daily is taken, the second tablet should not be taken any more than 8 hours after the first.