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

Aim Cardiovascular disease (CVD) is common amongst frail older people. The evidence base for CVD commonly excludes older adults with multimorbidity or chronic conditions. Most cardiovascular drugs have the potential to lower blood pressure (BP) and therefore cause medication-related harm (MRH). We aimed to identify key clinical and sociodemographic characteristics associated with MRH in older people taking BP-lowering drugs for whatever indication they were prescribed. Methods The PRIME (prospective study to develop a model to stratify the risk of MRH in hospitalised elderly patients in the UK) study investigating the incidence and cost of MRH in older people across Southern England. 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 BP-lowering drugs (as defined by National Institute for Health and Care Excellence hypertension guidelines) were included in this analysis. Results One hundred and four (12%) study patients experienced a total of 153 MRH events associated with BP-lowering drugs. Patients on four BP-lowering drugs were five times more likely to experience MRH compared to those taking one medication (OR 4.96; 95%CI 1.63–15.13; P = 0.01). Most MRH events were classified ‘serious’ (80%, n = 123), requiring dose change or treatment cessation. Almost half of MRH were potentially preventable (49%, n = 75). Conclusion Polypharmacy from BP-lowering drugs in older people is associated with preventable harm. Decisions around cardiovascular risk reduction should be carefully considered in view of MRH arising from BP-lowering drugs.