What is polypharmacy?
While polypharmacy is often clinically appropriate, each additional medicine increases the risk of ADRs, drug–drug interactions, and patient harm. Polypharmacy also contributes to antimicrobial resistance, increases the complexity of administration schedules, and may negatively impact adherence.
Appropriate and problematic polypharmacy
Appropriate polypharmacy
Appropriate polypharmacy supports better health outcomes in people with complex needs. This occurs when:
- Each medicine is prescribed for a clear, evidence-based indication
- Benefits outweigh the potential risks
- Therapy aligns with the patient’s goals of care
- Prescribing is subject to regular structured medication review in line with national policy.
Problematic polypharmacy
Problematic or inappropriate polypharmacy arises when medicines:
- Are prescribed without ongoing indication or clear clinical need
- Pose unacceptable risks of ADRs or interactions
- Are used to treat side effects of other medicines (a “prescribing cascade”)
- Duplicate therapeutic classes unnecessarily
- Are continued indefinitely without review.
Problematic polypharmacy can lead to avoidable harm, hospital admissions, poorer quality of life, and increased health and social care costs. Identifying it requires collaboration across the multidisciplinary team, including prescribers, pharmacists, nurses, and patients. Research has found ADRs in 18.4% of hospital admissions.
In 16.5% of admissions, it was the primary cause or a contributing cause, suggesting ADRs have a significant burden on hospital admissions. This is more than double the 6.5% found in another study which consisted of broadly the same geographical area. Most implicated medicines included diuretics, steroid-based inhalers, anticoagulants, proton pump inhibitors (PPIs), antiplatelets, chemotherapy agents, antihypertensives, opiates and antidepressants/antipsychotics.
What are the risks of polypharmacy?
Common risks and harms include:
- Adverse drug reactions (such as gastrointestinal bleeding with NSAIDs, hypoglycaemia with insulin, delirium with anticholinergics)
- Falls, dizziness, or orthostatic hypotension, particularly in frail or older adults
- Cognitive impairment or delirium
- Acute kidney injury, especially with nephrotoxic agents or polypharmacy in chronic kidney disease
- Hospitalisation, often due to preventable medication-related harm.
These risks are amplified in patients with reduced physiological reserve, polypharmacy involving high-risk medicines (such as opioids, anticoagulants, psychotropics), and those with limited social support.
Symptoms and signs suggesting problematic polypharmacy
Clinical indicators may include:
- Fatigue, sedation or drowsiness
- Loss of appetite or weight loss
- Confusion or worsening cognitive function
- Dizziness, postural instability, and increased falls risk
- Skin reactions suggestive of ADR
- Gastrointestinal disturbance (such as diarrhoea, constipation, nausea)
- Mood changes, anxiety, or depression secondary to medication effects.
These should trigger clinical review and structured medicines optimisation.
Who is most at risk from polypharmacy?
Groups at higher risk of problematic polypharmacy include:
- Older adults (≥65 years)
- Individuals living with frailty or multimorbidity
- People with cognitive impairment or reduced renal/hepatic function
- Residents in care homes
- Patients with frequent unplanned hospital admissions or multiple prescribers
- Socio-deprived communities.
For these patients, proactive monitoring and medicines review are crucial to reduce harm.
How to prevent problematic polypharmacy
- Structured medication reviews: Undertake regular, holistic medication reviews to assess ongoing clinical need, indication, effectiveness, and safety. Each medicine should be linked to a diagnosis or therapeutic goal.
- Multidisciplinary working: Ensure shared decision-making between GPs, pharmacists, specialists, nurses, and patients. Consistent communication is essential to avoid duplication and inappropriate prescribing.
- Shared decision-making and patient education: Empowering patients to understand their medicines, including expected benefits and side effects, supports adherence and early reporting of issues.
- Deprescribing where appropriate: Identify medicines that no longer provide benefit or pose unacceptable risk. Withdraw these systematically, in line with clinical guidance, to minimise harm.
- Consideration of non-pharmacological options: Lifestyle measures, self-management support, and targeted interventions may reduce the need for multiple medicines.
How to manage deprescribing
Deprescribing should be:
- Clinically led, with multidisciplinary input
- Patient-centred, involving discussion about goals of care and potential withdrawal effects
- Evidence-informed, drawing on NICE guidelines and local formulary recommendations
- Monitored, with appropriate follow-up and safety-netting.
Examples include reducing benzodiazepines, stopping long-term proton pump inhibitors where no longer indicated, and rationalising cardiovascular therapies in patients nearing end-of-life.
The 7 steps to appropriate polypharmacy
Developed by Scotland’s Right Decision Service, the 7 steps to medication review is a structured approach to reviewing patients.
- Aim: What matters most to the patient?
- Need: Which medicines are essential to meet clinical goals?
- Review: Which medicines may no longer be needed?
- Effectiveness: Are medicines achieving therapeutic outcomes?
- Safety: Are there risks of ADRs or interactions?
- Sustainability: Is the regimen cost-effective and practical for the NHS and the patient?
- Adherence: Is the patient able and willing to take medicines as prescribed?
Further resources and best practice for polypharmacy
- Health Innovation Network national polypharmacy programme
- National Institute for Health and Care Excellence guidance on multimorbidity and polypharmacy
- NHS England medicines optimisation programmes
- Medicines and Healthcare products Regulatory Agency safety alerts
- NHS Scotland 7 steps medication review
Join UKCPA to stay on top of polypharmacy best practice
Become a UKCPA member for £119 per year to keep up with best practice guidance, share knowledge with fellow pharmacists, and connect with your peers across the UK and beyond. Membership provides you with:
- Access to an extensive library of pharmacy resources
- Ongoing training and education, led by experts
- An opportunity to join communities dedicated to different pharmacy specialisms
- A chance to contribute and learn from forum discussions on specific aspects of pharmacy practice
- A calendar of in-person and virtual networking events, where you can connect with fellow pharmacy professionals
