Background: Azithromycin has been associated with an increased risk of cardiovascular death. Patients with baseline cardiovascular disease have been reported to have higher rates of cardiovascular death with azithromycin. However, the risk of cardiovascular death among younger persons prescribed 1 or 2 grams of azithromycin has not been reported.
Methods: We analyzed data in the 2011 MarketScan administrative claims database to estimate rates of cardiovascular death among persons aged 15-44 years who were prescribed 250-500 milligrams of azithromycin, 1-2 grams of azithromycin, or 100 milligrams of doxycycline. We identified cardiovascular deaths using MarketScan codes for discharge status and ICD9 codes for cardiovascular diagnoses. We required that each course of treatment be separated by at least 30 days, and estimated the number of deaths occurring within 5, 10, and 30 days of the prescription date.
Results: Our preliminary findings among 3.0 million persons aged 15-44 years who were prescribed azithromycin or doxycycline were that 14,681 prescriptions (0.5%) were for 1-2 grams azithromycin; 2,359,460 (79.3%) for 250-500 milligrams azithromycin; and 602,205 (19. 6%) for doxycycline. Persons who were prescribed 1-2 grams azithromycin were younger (mean of 27 years) than those prescribed 250-500 milligrams azithromycin (30 years) or doxycycline (29 years) (p<0.001). About 63% of prescriptions were for women. No deaths were identified among persons prescribed 1-2 grams azithromycin. Among persons prescribed 250-500 milligrams azithromycin, one person (0.00004%) died within 5 days, 2 (0.00009%) within 10 days, and 5 (0.0002%) within 30 days of the prescription. Among those prescribed doxycycline, there were no deaths within 5 days or 10 days, and 3 deaths (0.0005%) within 30 days.
Conclusions: 1-2 grams of azithromycin were not associated with cardiovascular death in persons aged 15-44 years. These results might provide some reassurance for providers who prescribe 1-2 gram azithromycin, such as for patients diagnosed with STDs.