Development and Application of the GheOP3S-Tool Addendum on Potentially Inappropriate Prescribing (PIP) of Renally Excreted Active Drugs (READs) in Older Adults with Polypharmacy

Abdul Aziz Al Wazzan, Eline Tommelein, Katrien Foubert, Stefano Bonassi, Graziano Onder, Annemie Somers, Mirko Petrovic, Koen Boussery

Renal function progressively worsens with age. Potentially inappropriate prescribing (PIP) of renally excreted active drugs (READs) is common in older adults, leading to an increased rate of iatrogenic illness. The Ghent Older People's Prescription community Pharmacy Screening (GheOP3S-) tool is an effective, explicit instrument that was developed for community pharmacists (CPs) to detect PIP. So far, this tool does not assess PIP of the frequently used READs in older patients with renal impairment. This study aimed to expand the GheOP3S-tool with the first addendum to screen for PIP of frequently used READs, and to perform a cross-sectional analysis using the addendum and the medication history of a group of older adults with polypharmacy. The addendum was developed in three steps: (1) collection of individual and combined READs, (2) collection of dose-adjustment recommendations, and (3) expert panel evaluation. Consequently, the addendum was applied retrospectively on the medication list of 60 older adults with polypharmacy and with four renal function-estimating equations. The addendum includes 61 READs recommendations for dose/drug-adjustment alternatives, laboratory test follow-ups, and patients' referral to specialists' care. In the cross-sectional analysis, 35-78% of patients were diagnosed with renal impairment, depending on the equations used for renal function estimation. Among patients with renal impairment, 21-46% of the prescribed READs were deemed potentially inappropriate by the GheOP3S-tool addendum. The GheOP3S-tool was expanded with an addendum on PIP of READs in renal impairment for older patients. The cross-sectional analysis using the addendum suggests that PIP of READs is common in older patients with polypharmacy and renal impairment. Using this addendum, CPs might contribute to diminishing PIP of READs.