Narcotic analgesics and other antianginal drugs

Abstract

The effect of metoprolol on chest pain has been assessed in terms of the duration and the use of narcotic analgesics, nitrates and calcium-channel blockers. Fewer metoprolol-treated patients in the MIAMI trial were given narcotic analgesics (49% of the placebo patients vs 44% of the metoprolol patients, p < 0.001), nitrates (55% vs 53%, p = 0.10) and calcium-channel blockers (12% vs 9%, p < 0.001). A total number of 6,697 dose equivalents of narcotic analgesics were given to the placebo group compared with 5,493 dose equivalents to the metoprolol group, a difference of 18% (p < 0.001). Mean dose equivalents were 2.3 and 1.9, respectively. The analysis of the total use of the 3 types of treatment for ischemic chest pain showed a significantly less frequent use of treatment for chest pain in the metoprolol group than in the placebo group (p < 0.004). The relative difference in the incidence of drug treatment tended to be more striking for patients with maximal therapy, i.e., receiving high doses of narcotic analgesics, nitrates and calcium-channel blockers. There were 22% fewer patients receiving 4 or more doses of narcotic analgesics in the metoprolol group than in the placebo group. A multivariate analysis disclosed that site of suspected infarction, delay time, entry systolic blood pressure and metoprolol treatment all had a significant effect on the use of narcotic analgesics. There was a nonsignificant tendency for heart rate to be of importance. In the placebo group the use of narcotic analgesics increased with decreasing delay time and increasing systolic blood pressure. The use was highest for patients with signs of anterior infarction on electrocardiogram (ECG) and lowest for patients with normal ECG at entry. The effect of metoprolol was independent of delay time and systolic blood pressure but varied with ECG classification. The highest effect was seen among patients with signs of anterior infarction.