CIBA-GEIGY's LOPRESSOR MYOCARDIAL INFARCTION INDICATION

CIBA-GEIGY's LOPRESSOR MYOCARDIAL INFARCTION INDICATION was approved by FDA March 30. Labeling for the new indication states that Lopressor ampules and tabs are "indicated in the treatment of hemodynamically stable patients with definite or suspected acute myocardial infarction to reduce cardiovascular mortality." Lopressor (metoprolol) is the third beta blocker to receive approval for the prevention of cardiovascular death, following Merck's Blocadren and Ayerst's Inderal, and the only I.V. approval. Labeling notes that "during the early phase of a definite or suspected acute myocardial infarction treatment with Lopressor can be initiated as soon as possible after the patient's arrival in the hospital. Such treatment should be initiated in a coronary care or similar unit immediately after the patient's hemodynamic condition has stabilized." Alternatively, the labeling adds, "treatment can begin within 3 to 10 days of the acute event." Lopressor's labeling differs from that of the other two beta blockers, which are indicated for definite post-myocardial infarction. Inderal is "indicated to reduce cardiovascular mortality in patients who have survived the acute phase of myocardial infarction and are clinically stable." Blocadren labeling points specifically to reduced risk of reinfarction and says treatment should be initiated "within one to four weeks after infarction." Like Blocadren and Inderal, Lopressor has a b.i.d. maintenance regimen. The initial dose of Lopressor for patients receiving early treatment consists of three bolus injections of 5 mg each given at approximately two minute intervals. In patients who tolerate the full I.V. dose, "Lopressor tabs, 50 mg every six hours, should be initiated 15 minutes after the last I.V. dose and continued for 48 hours," the labeling states. "Thereafter patients should receive a maintenance dose of 100 mg daily." The labeling adds that "although the efficacy of Lopressor beyond three months has not been conclusively established, data from studies with other beta blockers suggest that treatment should be continued for one-to-three years." In a press release announcing approval of the drug, Ciba-Geigy cited a double-blind placebo-controlled study involving 1,395 patients conducted by Ake Hjalmarson at the University of Goteborg in Sweden. The study found Lopressor reduced the chance of mortality by 36% during the first three months after a heart attack. FDA's Cardio-Renal Advisory Cmte. gave preliminary clearance to the supplemental indication for Lopressor in June 1982. At that time, however, FDA did not ask for a recommendation on approval since data was incomplete.