Study on polypharmacy and potential drug â?? drug interactions in drug therapy of elderly patients at a tertiary care teaching hospital

Binay Gupta1,*, Jitty Jose1, Arun Roy1, Divya Jyothi1, Rajeswari Ramasamy2, TV Venkatadri3, Shashidhar G3

The administration of many drugs at the same time or the administration of an excessive number of drugs can cause the potentially serious drug-drug interactions and adverse drug events. Adverse drug events and serious harms occurs at all ages, although they are more commoner in older people, who are more vulnerable to drug toxicity because of age related physiologic changes and increased risk of disease associated with aging and because of polypharmacy. The objective of this study was to identify the degree of polypharmacy and the frequency of potential drug- drug interactions in the medication regimen of elderly patients. This is a cross – sectional observational study conducted in the general medicine department of a tertiary care teaching hospital over a period of 6 months. Sample size of 150 cases of elderly patients was collected from general medicine ward and was reviewed for polypharmacy and potential drug-drug interactions. From among the 150 cases collected, 65(43%) cases were identified with polypharmacy out of which 23(35%) were male and 42(65%) were female. The average number of drug prescribed per patient was 6.05. Among 150 cases, 71(47%) cases were identified with 152 potential drug-drug interactions out of which 8 cases (11%) were with clinically observed adverse drug reaction due to drug interactions. Majority of the potential drug-drug interactions were pharmacodynamic in nature (67%). It was observed that out of 152 pDDIs identified,17(11%) were major, 110(72%) were moderate and 25(16%) were minor in severity.