Appropriateness and surveillance of medication in a cohort of diabetic patients on polypharmacy

Abstract

It is assumed that with increasing polypharmacy, medication surveillance by the General Practitioner (GP) and adherence to the therapy regimen by the patient will both decline. We evaluated clinical and medication records taken from GP documentations in a cohort of 102 diabetic patients (48 f, 54 m, median age 70, range 39 - 81) with 3 or more chronic prescriptions. Patients were asked about their current medication and its tolerability by means of a structured telephone interview. 45% of the patients received up to 6 medications, 36% 7 - 9 and 19% > 10. The main comorbidity was hypertension (93%) and symptomatic CAD (39%). The use of established medications (beta-blockers and ACE inhibitors) for these comorbidities was appropriate. Although 76% were eligible for a statin therapy, only 51% actually took a statin, and 28% had a dose lower than the defined daily dose. 68% of the patients had no prescriptions other than those recorded in the GP documentation, but 8% of the total number of medicines taken by the patients were not recorded in the GP's database. 62% of patients took all the medication prescribed by the GP, while 7% of all medicines recorded in the GP's database were not taken by the patients. In 10% of cases, an incompatible medication (defined in accordance with a consented list) was taken by the patient. 81% of patients regularly (twice per year) had their HbA1c checked, but only 62% had their potassium levels checked, despite the use of ACI and diuretics. Most patients knew the reason for taking at least one medication, but 18% knew this for less than half of their (multiple) medications. 70% of the patients said they had been informed about the possible risks of their medication by the GP, and 7% knew the risks for only one medication. In this cohort of patients on polypharmacy and with a high risk profile for adverse drug reactions, we found a mismatch between GPs' documentation of prescriptions and the medication taken by the patient. Patients had no detailed knowledge about indications and almost no knowledge about risks. Although the overall performance of therapy (appropriateness) was deemed sufficient, there would appear to be room for improvement in order to fill information gaps and strive for stricter surveillance.