~-BLOCKERS IN MYOCARDIAL INFARCTION

Oral pindolol seemed to do no harm, but did it do any good? There is no consensus as to the role of ~·blockers in acute myocardial infarction. While there is good reason to believe that they may be of value, fear of side effects has restricted their use in early infarction. There were no serious side effects, however, in 30 patients given oral pindolol (5mg 8-hourly) starting 5-19 hours after onset of acute myocardial infarction and continued for at least 48 hours. There was only I hospital death and 2 late deaths (2 weeks and 5 months after discharge). Pindolol did not precipitate cardiac failure or conduction disturbances and was associated with only 3 minor episodes of hypotension and I of bradycardia. Absorption of pindolol from the gastrointestinal tract was unpredictable in patients with acute infarction (possibly at least partly due to use of narcotic analgesics) and IV use is recommended, atleast during the first 12 hours. 'While pindolol did not appear to do harm, it is impossible to say that it did any good.' O·Rourke. M.F. et aI.: Australian and New Zealand Journal of Medicine 9: 408 (Aug 1979)

IV alprenolol reduces the mortality rate in patients younger than 65 years In a double-blind study in 482 patients with defiI'ite or suspected myocardial infarction, alpreno!ol significantly reduced mort.ality rate (20 % mortality in the placebo group vs 9 % with alprenoloO and had no adverse effects on patients without definite infarction. There was a significant reduction in mortality rate of patients with definite infarction - 28 % (placebo) vs 15% (alprenolo)). Mortality was not reduced in patients over 6 5 years of age. Treatment was started as soon as possible after admission with 5 mg alprenolol / placebo IV and a second injection I 0 minutes later if BP or heart rate had not dropped by 10% or more. Three hours after injection the patient was started on oral treatment with 200mg bid of a sustained release preparation, 'Aptin Durules', or placebo. Because of a trend towards higher mortality in patients > 65 years of age on alprenolol, routine usetof ~-blockers in elderly patients with acute myocardial infarction is not recommended.

'In patients aged 65 or less with chest pain and su.spected acute myocardial infarc­tion routine treatment with alprenolol can be advocated. This treatment should be started as soon as possible on admission.'

Andersen. M.P. etal.: Lancet 2: 865 (27 Oct 1979)

And oral atenolol improves recovery of ECG signs 22 patients aged 46-70 with definite evidence of a recent anterior transmural myocardial infarct were randomised to treatment . with I OOmg atenolol or placebo daily. The most notable changes in 35·1ead precordial ECGs in the first 6-12 months after infarction were reduced Q wave amplitude and significantly increased R wave amplitude. Patients given atenolol show.ed a significantly greater recovery in R wave amplitude and reduction in Q waves than patients on placebo. Yusuf. S. et aI.: Lancet 2: 868 (27 Oct 1979)

10 INPHARMA 10 Nov 1979 0156-2703/79/1110-0010 $0 .50/0 ~ ADIS Press