~-BLOCKERS ARE VALUABLE IN ACUTE MYOCARDIAL INFARCTION (AMI)

Metoprolol reduces mortality in AMI by 36% In a double-blind study, 1395 patients with definite or suspected AMI were randomised either to oral metoprolol I OOmg bid (after a 15mg IV bolus) or placebo shortly after their arrival to hospital. Therapy was continued for 90 days. 43.6 % of all patients were started on treatment within 6 hours of the onset of chest pain, 69 % within 12 hours, and 90.7% within 24 hours. Only 32 patients in the metoprolol group, compared with 55 in the placebo group, needed lignocaine (lidocaine) to control ventricular tachycardia and fibrillation. Significantly fewer deaths occurred in the metoprolol patients (5 .7 % ) than in placebo patients (8.9%). This represents a 36% reduction in death due to AMI. Hjalmarson. A. et aI. : Lancet 2: 823 (17 Oct 198 I)

And the use of timolol to prevent re-infarction is now OK'd in UK During the first year after an AMI, there is an estimated 30-fold increase in death rate. The value of metoprolo\ in reducing the mortality due to AMI, as seen in the above study, has also been paralleled by timolol. The Committee on Safety of Medicines has now approved timolol maleate for use in the prevention of re-infarction and cardiac death in AMI patients. This new indication for timolol has been approved because a recent study showed significant reductions over 12 months in mortality (by 40 %) and re­infarction (by 30 %) in patients given timolol between 7-28 days after an AMI. Unlike with metoprolol in the above study, timolol was not started during the acute phase of infarction. While metoprolol is relatively cardioselective, timolol is not. The mechanism of the cardioprotective effect of ~-blockers is not known. The manufacturers of timolol recommend that timolol be given to postinfarction patients at a dose of 5mg bid for 2 days, increasing to 1 Omg bid thereafter. 'Many more studies with other beta-blockers are in progress, but the timolol and metoprolol results, taken together, would seem to present an increasingly strong case for the use of prophylactic beta-blockade.' Pharmaceutical Journal 227: 499 (24 Oct 1981)

0156-2703/81/1107.0011 $00.50/0 ©ADISPress INPHARMA 7 Nov 1981 11