The Role of Clinical Pharmacists in Preventing Medication-Related Harm in Older Adults: A Systematic Review

Abstract

Background: Older adults carry a disproportionate share of medication-related harm because of multimorbidity, polypharmacy and age-related changes in drug handling. Clinical pharmacists are increasingly placed on wards, in clinics and in care homes to prevent this harm, yet trials report inconsistent results. In Saudi Arabia, where more than half of older outpatients receive at least one potentially inappropriate medication, controlled evidence from local practice is scarce.

Objective: To synthesise controlled-trial evidence on the effect of clinical pharmacist interventions on medication-related harm and its precursors in adults aged 65 years and older, and to set this evidence against the Saudi and Gulf context.

Methods: PubMed was searched for randomised and cluster-randomised trials published from January 2015 to 4 November 2026, following PRISMA 2020. Eligible trials tested a pharmacist-led or pharmacist-delivered intervention in older adults and reported prescribing appropriateness, drug-related problems (DRPs), adverse drug events (ADEs) or medication-related health-care use. Supplementary searches targeted Saudi Arabia and the Gulf Cooperation Council (GCC) countries. Results were synthesised narratively by outcome domain and care setting.

Results: Of 51 unique records, 18 trials (12,450 participants; 15 countries) met the criteria; one was conducted in the Middle East and North Africa (Jordan) and none in Saudi Arabia or the GCC. Twelve trials reported a statistically significant benefit on their primary harm-related outcome, two reported mixed results and four were null. Benefits were most consistent for prescribing appropriateness (6 of 8 trials) and for transitions of care, where pharmacist follow-up reduced repeat emergency visits and readmissions. Large pragmatic trials of discharge services showed little overall effect but signalled benefit in patients with low adherence or literacy. Physicians accepted a median of 84.0% of pharmacist recommendations (range 42.4%–94.8%).

Conclusions: Clinical pharmacist interventions reliably reduce inappropriate prescribing and DRPs in older adults and can lower medication-related hospital use when they bridge care transitions. Saudi and Gulf hospitals have high baseline rates of inappropriate prescribing but no controlled trials; locally conducted trials with clinical end points are needed.