The study was conducted in Arnhem, a city in the East of the Netherlands with nearly 148 000 inhabitants. Seven GPs, belonging to the same pharmacotherapy audit meeting group, participated in the study. Five pharmacists who worked in close collaboration with this group selected the patients in their pharmacy computer system. Patients aged ≥70 years in the care of the participating GPs were eligible if they were on GP-prescribed maintenance therapy of blood-glucose-lowering or cardiovascular drugs (for example, digoxin, diuretics, or inhibitors of the renin–angiotensin system [RAS], including angiotensin-converting enzyme [ACE] inhibitors and angiotensin II receptor blockers [ARBs]). Patients also used at least one ‘target drug’ on the inclusion date of 4 January 2010. ‘Target drugs’ were defined as drugs requiring therapeutic advice in patients with decreased renal function considering the Dutch dosing guideline for impaired renal function.17 Patients with an estimated glomerular filtration rate (eGFR) <10 ml/min/1.73 m2 were excluded (Figure 1).
How this fits in
Patients who use drugs that interact with impaired renal function require monitoring of renal function to avoid medication errors. In daily practice, the adjustment of medication in relation to renal function does not always get the attention that it deserves. The use of a pharmacy medication alert system based on renal function may be of additional value. In this study, the use of such a system resulted in therapeutic advice concerning 11% of the drugs that interact with renal function, and the GP agreed with half of the therapeutic advice.
The GPs already used a computerised medication monitoring system. This system generated an alert when the GP prescribed a target drug in patients labelled as having CKD, but it could not consider the eGFR level.
The use of drug dispensing data and laboratory test results in this study complied with Dutch privacy regulations.
