Patients with multiple medical conditions typically take multiple medicines, which is known as polypharmacy. In the UK, up to 11 per cent of unplanned hospital admissions are attributable to medication-related adverse events. Of these, 70 per cent occur in elderly patients on multiple medicines, 50 per cent of which are deemed preventable.  

In most European countries, people can now expect to live beyond the age of 80, but evidence shows that the average healthy life years (HLY) for EU citizens is 61, meaning that many people are living for around 20 years in sub-optimal health. Each condition a patient suffers from is treated individually, which inevitably leads to the use of multiple medications, the risks and benefits of which are largely unproven and often unpredictable.

It is important to note that polypharmacy is not inappropriate per se and is often beneficial. For example, effective secondary prevention of myocardial infarction (heart attack) requires the use of at least four different classes of drugs: antiplatelets, statins, angiotensin-converting enzyme (ACE) inhibitors and beta-blockers. However, polypharmacy becomes inappropriate when the risks of multiple medications begin to outweigh their potential benefits for an individual patient. ‘Deprescribing’ has become a buzzword in the NHS and this module will put it in context and help set out what it means for patients and pharmacy professionals.

Appropriate polypharmacy should be considered at every point of initiation of a new treatment for the patient, and when the patient moves across different healthcare settings. The pharmacy team might be the only ones who see the full picture, enabling them to identify potentially inappropriate polypharmacy in terms of possible adverse drug reactions (ADRs) and whether a patient adheres to treatment.

The risk of harm is generally higher in older people with multimorbidity than in younger patients. This is due to older people’s reduced ability to clear drugs (e.g. due to renal and/or hepatic impairment) and increased vulnerability to medication burden and drugs’ adverse effects – due to general frailty and drug-drug and drug-disease interactions. However, the increased risk of harm is not always offset by increased benefits, and for many preventive medicines, such benefits may never be realised due to a shortened life expectancy.