Side Effects of Aldactone with Septra, Bactrim May Increase Risk of Death for Elderly: Study

Canadian researchers warn that elderly patients may face a higher fatality risk if they combine the medication Aldactone with certain antibiotics, such as Septra or Bactrim. 

In a study published in the Canadian Medical Association Journal on February 2, researchers looked at the risk of combining the antibiotic trimethoprim-sulfamethoxazole, sold under the brand names Septra and Bactrim, with the diuretic Aldactone (spironolactone).

The study was conducted because it is already known that Aldactone, Septra, and Bactrim separately increase the risk of high potassium levels, known as hyperkalemia, which can cause heart rhythm problems. Researchers wanted to determine if this risk translated into an actual increased risk of death for some patients.

Researchers looked at data on nearly 12,000 patients who died suddenly while taking Aldactone. They found 328 cases which occurred within 14 days of the patients taking an antibiotic, most of whom were over the age of 65.

According to the findings, the rate of death among patients on Aldactone who were given Septra or Bactrim after just two weeks was twice that of patients given other antibiotics. While they also found a possible association between the use of Cipro and nitrofurantoin, the link between those antibiotics and sudden death in Aldactone patients was less certain.

The consumer watchdog group Public Citizen warned of hyperkalemia risks linked to the combination of Aldactone and Septra in late 2011, indicating that patients should let their physician know they are on Aldactone if they are being treated for a urinary tract infection and to make sure their health care provider is aware of the potential risks of combining the two drugs. They also warned patients in their “Worst Pills, Best Pills” Newsletter to be aware of the potential symptoms if they are on the two drugs or any drugs that increase potassium blood levels, and to seek immediate medical attention if the symptoms occur.

Aldactone (spironolactone) was approved by the FDA in 1985 as a diuretic. Originally manufactured by Pfizer, it is available as a generic.

Septra (sulfamethoxazole and trimethoprim; also known as cotrimoxazole) was approved as an antibiotic by the FDA in 1973 and is widely available as a generic. The brand name versions, Septra and Septra DS, are distrubited by Monarch Pharmaceuticals, a division of King Pharmaceuticals. Bactrim is available as a generic.

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