Drug Prescribing for Patients with Chronic Kidney Disease in General Practice: a Cross-Sectional Study

Background Many drugs require dose adjustment or are contraindicated in patients with chronic kidney disease (CKD) to avoid adverse events. The aims of this study were to assess if medication was appropriately dose adjusted in patients with CKD in primary care, to identify medications that were frequently prescribed inappropriately and to identify factors predicting mal-prescription. Methods We conducted a cross-sectional observational study in 34 general practioners' offices, assessing the medication of patients with CKD stage 3 according to the corresponding pharmaceutical product information. Additional information was extracted from recommendations of scientific societies and regulatory authorities. Contraindicated and overdosed medications were identified. Predictive factors for inadequate prescribing were analyzed with multiple logistic regression. Results 589 patients (O 78 years, 63% female) with CKD stage 3 were included. A total of 5102 medications were extracted from the medication sheets (94,6% regular, 5,4% as needed). 4,2% were judged as being inadequate according to pharmaceutical information (2,1% contraindicated, 2,1% overdosed). 173 patients (29%) had 1 inadequate prescription. The proportion of inadequate prescriptions fell to 3,5% after adjustment for the most recent recommendations of scientific societies and regulatory authorities. Most frequent inappropriate prescriptions were ACE-inhibitors, diuretics, oral antidiabetic drugs, methotrexate and potassium supplements. Most important predictors for inadequate prescriptions were CKD stage 3b and number of medications. Conclusion A quarter of all patients had a least one inadequate prescription. The overall proportion of inadequately prescribed drugs was low. Adjustment for recommendations by scientific societies and regulatory authorities further reduced the number of inadequate prescriptions. Valid data on the clinical relevance of inadequate prescriptions is scarce and further research is required. Because of the time and effort needed to assess all medications, future quality improvement projects should focus on CKD stage 3b, patients with polypharmacy and crucial medication.