Introduction:

The increased risk of sudden death and hospitalization due to hyperkalemia in patients consuming potassium-sparing drugs and trimethoprim has been described. Therefore, the frequency of the potential interaction between spironolactone and trimethoprim-sulfamethoxazole in patients older than 60 years of Colombia was sought.

Methods:

observational study. From a database of 3.6 million people, patients older than 60 years who received spironolactone on an outpatient basis for at least three consecutive months and patients with a prescription for trimethoprim-sulfamethoxazole between 08/01/2014 and 07/31/2015 were selected. Subsequently, those with joint prescription during the same month were identified. Sociodemographic variables, concomitant use of renin angiotensin system inhibitors, diuretics and inotropes were included.

Results:

During the year of study, 8941 patients older than 60 years with continuous spironolactone prescription, and 8028 patients with trimethoprim-sulfamethoxazole, were found. Its co-prescription was detected in 77 patients (0.8% of patients with spironolactone), with a cumulative incidence of 0.86 cases per 100 patients-spironolactone / year. The mean age of these patients was 79.1 ± 14 years, 57.1% were men, and the city with the most cases was Cali (13% of the total). 68.8% of the cases also had concomitant medication with losartan and 62.3% with furosemide.

Conclusions:

The interaction between spironolactone and trimethoprim-sulfamethoxazole in a Colombian population is relatively infrequent; however, due to the risks to which the elderly patient is exposed, it is relevant because of its morbidity and mortality implications, requiring to be known and monitored by the prescribing physician. (Acta Med Colomb 2017; 42:189-192).