Characterising older adults' risk of harm from blood-pressure lowering medications: a sub-analysis from the PRIME study

Introduction Hypertension is a major risk factor for cardiovascular disease and death. Randomised trials in older adults with relatively few co-morbidities recommend treatment of their hypertension [1]. However, blood-pressure lowering medications increase the risk of medication-related harm (MRH) from adverse drug reactions (ADRs), non-adherence, medication errors and drug–drug interactions. We aimed to identify characteristics associated with MRH in older people on blood-pressure lowering medications. Method The PRIME (prospective study to develop a model to stratify the risk of MRH in hospitalized elderly patients in the UK) study investigating the incidence and cost of MRH in 1280 older people in Southern England [2]. Adults =65 years were recruited from five teaching hospitals at hospital discharge and followed up for 8-weeks. Telephone interviews with study participants, review of primary care records and hospital readmissions were undertaken to identify MRH. PRIME study participants taking blood-pressure lowering medications, as defined by National Institute for Health and Care Excellence hypertension guidelines [3], were included in this analysis. Results Sixty-six percent of the PRIME cohort (n?=?841) were taking blood-pressure lowering medications. Patients on four blood-pressure lowering medications were five times more likely to experience MRH compared to those taking just one medication (OR 4.96; 95%CI 1.63-15.13;p?=?0.01). Most harm events were serious (80%,n?=?123), requiring dose change or treatment cessation. Most MRH cases were potentially preventable (49%,n?=?75). Conclusion MRH from blood-pressure lowering medication in older people is common, serious, and potentially preventable. Decisions around maximising cardiovascular risk reduction must be carefully considered in the context of MRH from blood-pressure lowering medications.