Patient's lack of understanding producing insulin drug-interactions in Southeast Brazilian primary care clinics.

Unlabelled: Detrimental drug-drug interactions (DDIs) in Diabetic patients could be from the simultaneous use of multiple drugs, polypharmacy. Brazilian public health studies evaluating the practical knowledge about drug interactions are scarce. This study's objective is to identify drug interactions and prevalence of detrimental DDIs in diabetic patients attending Brazilian basic health system clinics.

Methods: Patients using insulin between the age of 18-90 years were selected to complete the MedTake questionnaire, to evaluate the indication, dosage, regimen and drug interaction. The MedTake test was employed. For each medicine, the test was scored as the percentage of correct actions and compared with printed instructions one single researcher downloaded all the data was from the municipality's computerized system.

Results: The median age of recruits was 60.2 ± 14.3 and MedTake test scores were low 60.3 ± 20. One hundred patients missed the correct dose question, 40 missed why they were prescribed the drug, indication and 65 missed the therapeutic regimen. These diabetes patients did not know the DDIs between insulin combined with other medicines. Drugs that had more interaction with insulin were: acetylsalicylic acid (40%), enalapril (18%), losartan (32%) and hydrochlorothiazide (23%).

Conclusions: Diabetes patients without practical knowledge about insulin interacting with other pharmaceutical drugs that can produce DDIs with other medicines illustrates a need to develop education programs for diabetics.