Reviewed by Shameer Deen, ST5 Urology Registrar
Polypharmacy — commonly defined as the concurrent use of five or more medications — affects up to 40% of older adults [1]. While each individual prescription may be appropriate, the cumulative burden of multiple drugs introduces risks that grow non-linearly with every additional agent [2]. Here are five evidence-based principles for safer prescribing in polypharmacy.
1. Apply the Prescribing Pyramid
Before adding any new medication, work through a structured assessment: Is there a clear indication? Could a non-pharmacological intervention work? Is the patient already on a drug that could be optimised instead? The goal is to avoid "prescribing cascades" where a new drug is added to treat the side effects of an existing one [2].
2. Review the Full Medication List Regularly
At every clinical encounter, take the opportunity to review all current medications. Use a structured approach such as the STOPP/START criteria or the Beers Criteria to identify potentially inappropriate medications in older adults [3]. Many drugs initiated during an acute hospital admission are no longer needed once the patient has stabilised.
MedNext Formulary makes this straightforward — you can quickly look up each drug, check its indications, and cross-reference interactions across the entire regimen in real time.
3. Prioritise High-Risk Combinations
Not all drug interactions carry equal weight. Focus your attention on combinations known to cause serious harm [2]:
- Anticoagulants + NSAIDs — increased bleeding risk
- ACE inhibitors + potassium-sparing diuretics — hyperkalaemia
- Methotrexate + trimethoprim — bone marrow suppression
- SSRIs + tramadol or triptans — serotonin syndrome
- Multiple QT-prolonging agents — cardiac arrhythmia
4. Adjust for Renal and Hepatic Function
Organ function declines with age, and many commonly prescribed drugs require dose adjustment in renal or hepatic impairment [3]. Always check the estimated GFR before prescribing renally-cleared drugs, and use the dosing calculators in MedNext Formulary for weight-based and renal-adjusted dosing to avoid accumulation toxicity.
5. Communicate Clearly Across Care Settings
Medication errors are most common at transitions of care — hospital admission, discharge, and handover between teams [3]. Ensure accurate medication reconciliation at every transition. A complete, up-to-date drug list is the single most effective safeguard against prescribing errors in polypharmacy.
The Bottom Line
Polypharmacy is often unavoidable in older patients with multiple comorbidities, but the risks can be managed through systematic review, awareness of high-risk combinations, and appropriate use of clinical decision support tools. MedNext Formulary puts the data you need at your fingertips, so you can prescribe with confidence even in the most complex clinical scenarios.
References
- Masnoon N, Shakib S, Kalisch-Ellett L, Caughey GE. What is polypharmacy? A systematic review of definitions. BMC Geriatrics. 2017;17:230.
- Scott IA, Hilmer SN, Reeve E, et al. Reducing inappropriate polypharmacy. JAMA Intern Med. 2015;175(5):827-834.
- World Health Organization. Medication Safety in Polypharmacy. Technical Report. WHO, 2019.