The prevalence of potentially inappropriate medication prescribing in elderly patients with chronic kidney disease

Introduction Potentially inappropriate medication (PIM) prescribing is a global problem. Limited data are available on the prevalence of PIMs in elderly patients with chronic kidney disease (CKD). We examined the PIM prevalence in elderly patients with CKD, the most common drugs implicated and the levels of polypharmacy in this group. Methods A retrospective case record analysis of patients with CKD above the age of 70 years was carried out on 100 consecutive inpatients between January 2008 and June 2008 at a University Teaching Hospital. PIMs were defined using the modified Beers' criteria and latest British National Formulary (BNF) guidance for prescribing in patients with renal impairment using creatinine clearance calculated by the Cockroft-Gault formula. Results The mean age of the cohort was 80 years with a female predominance (62%). The mean estimated glomerular filtration rate (eGFR) was 17.2 ml/min/1.73 m(2). 56 patients had one or more PIMs prescribed during the acute admission period. 81 out of the 622 medications prescribed were 'inappropriate'; therefore, the prevalence of PIMs prescribed was 13%. Antibiotics and antihypertensives accounted for the majority of PIMs. Each patient received an average of six drugs. Conclusions The prevalence of PIMs in elderly inpatients with CKD is high. Inclusion of drugs prescribed acutely and use of the BNF to identify PIMs as well as the Beers' criteria may account for this. Use of screening tools may lead to better identification of PIMs in this high risk group. Routine calculation and documentation of eGFR on the medication chart on admission may help reduce PIMs.