Past use of erythromycin, tetracycline, or doxycycline is not associated with risk of first myocardial infarction

A population-based case-control study of patients enrolled at Group Health Cooperative of Puget Sound was conducted to evaluate whether past use of an tibiotics active against Chlamydia pneumoniae is associated with a decrease in the risk of first myocardial infarction (MI). Cases with incident fatal and nonfatal MI from mid-1986 through 1995 (n = 1796) were compared with r andomly sampled controls frequency-matched to cases for age, sex, and year (n = 4882). Use of erythromycin, tetracycline, or doxycycline during the pr evious 5 years was not associated with an alteration in the risk of first M I. In an adjusted logistic regression model, the odds ratios and 95% confid ence intervals for categories of cumulative duration of therapy with any of the three agents combined for 0, 1-14, 15-28, and greater than or equal to 29 days were 1.0 (reference), 0.93 (0.81-1.07), 0.99 (0.81-1.20), and 1.03 (0.84-1.26), respectively. These results suggest little or no association between past use of erythromycin or tetracycline antibiotics and the risk o f first MI among this population.