Background Deviation from the desired beneficial effects of medicines causes drug related problems (DRP). DRP are the cause of morbidity and mortality associated with medicines, and strategies are required to carry out an appropriate approach to this problem.

Purpose To analyse the pharmacotherapy of elderly patients with polypharmacy in order to detect and resolve DRP, classified according to the Third Consensus of Granada in our primary health centres.

Material and methods A descriptive, observational study in patients over 65 years and polymedicated (more than 6 drugs for at least 6 months). Period of study: June 2014–February 2015. Sample of patients obtained by simple random selection. Variables: age, sex, drug number per patient, and number and type of DRP per patient. Data source: electronic health record and electronic prescription recipe information system from the health service. Procedure: analysis of drug prescriptions, DRP detection and pharmaceutical interventions (PI) to the doctor if necessary.

Results The study population included 586 patients (61% females) with an average age of 79 years (66–103). Prescribed drugs: total 5686, average 9.7 (7–19) per patient. 49% of patients had at least one DRP (47% males vs 50% females).

The most prevalent DRP was ‘inappropriate dosing, regimen and/or treatment duration’ (39%), followed by ‘drug interactions’ (26%), ‘therapeutic duplication’ (17%), ‘probability of adverse reactions’ (8%) and others (10%). 80% of DRP were susceptible to PI. The number of PI increased to 468, the most prevalent were: ‘drug monitoring required’, ‘patient education about adherence and polypharmacy’, and ‘need for therapy revision’ (modification of dosing regimen followed by discontinue medication and substituting one drug for another). The PI achieved a prescriber acceptance of 41% and solved the DRP in 51% of patients.

The most prevalent diseases were: hypertension, osteoarthritis, dyslipidaemia, diabetes, cognitive impairment and chronic obstructive lung disease. There was a relationship between number of diseases and number of drugs prescribed.

Conclusion The medication review by pharmacists allowed identification of DRP in the elderly population, and it might be used as an important tool for optimising drug therapy. Integration of the pharmacist in the multidisciplinary team can help reduce DRP, improving the quality of drug prescriptions and patient safety.

No conflict of interest.