Potential interactions of antihypertensive drugs in a year of study of patients with hypertension treated in hospitals in 11 municipalities in the Department of Risaralda, Colombia

In diseases such as hypertension, commonly treatments with two or more drugs should be used, then their incorrect use can lead to drug interactions. In the context of the hypertension in Latin America, there are few studies assessing the magnitude of this problem. Current, observational, cross-sectional and census study was made in order to establish the potential occurrence of drug interactions in patients with hypertension from hospitals of 11 municipalities of Risaralda, Colombia, august 2009 to august 2010, using an algorithm designed to identify possible drug interactions. A total of 65 535 antihypertensive prescription records from 3 813 hypertension patients, 28.46.% corresponding to hydrochlorothiazide and 20.07 % to enalapril, among others, were obtained. From the total of patients 17.60 % (95 %CI 16.34 %-18.82 %) presented potential drug interactions, being highest at the municipality Dosquebradas (21.09 %; 95 %CI 18.79 %-23.36 %). Most frequent interaction was enalapril-hydrochlorothiazide (45.58 % of patients) and that of higher risk and frequency was enalapril-spironolactone (2.41 %). These results, reflected in part, the lack of adherence to hypertension treatment guidelines, as well few implementation of evidenced based treatment conducts, and possibly too difficulties in the university formation, lack of continue medical education programs, lack of interest and time to access to the alerts and reports of new conditions of drugs use and few instruction and teaching of evidence based medicine, aspects that needs to be integrally intervened with different approaches.