Combining commonly prescribed antibiotics with a widely used heart medication appears to more than double the risk of sudden death in seniors, finds a new study published in the Canadian Medical Association Journal. Spironolactone (Aldactone) is a common diuretic widely used in the treatment of heart failure. However, investigators have found that when trimethoprim-sulfamethoxazole (Septra, Bactrim) is prescribed to someone on Spironolactone, it can cause blood potassium to rise to potentially life-threatening levels. Over a 17-year period, almost 12,000 people died suddenly after taking this combination of medicines and most of the patients who died were over the age of 85. The authors conclude that pharmacists and physicians must be made aware of this interaction, as it does not appear widely known at present time.
Canadian Medical Association Journal, February 2015