Frequency of falls and quality of life in elderly nursing home patients receiving phenytoin

Background: Phenytoin is the most frequently prescribed anti-epileptic drug in nursing homes even though newer AEDs have a better safety profile. We sought to evaluate differences in baseline characteristics, frequency of falls and differences in quality of life of patients using phenytoin compared to other AEDs.

Methods: Residents from six nursing homes in Minneapolis/ St. Paul taking an AED, ≥60 years, and not residing in a rehabilitative care unit were included. Patients were classified as using phenytoin only or another AED (levetiracetam, lamotrigine, or gabapentin). Demographic information and co-morbidities were recorded at a baseline visit; number of falls and quality of life (EQ5D) were determined for 3 additional visits (4-6 weeks apart). Co-morbidities were used to derive a baseline Charlson score for each patient. Health state utilities were computed from EQ5D scores using US weights. Results were compared between groups using the Mann-Whitney U test. Results: There were 7 patients in the phenytoin group and 46 in the other AED group. Patients in the other AED group had higher Charlson scores (2.39 vs. 0.28, P-value<0.01) but no differences in other demographic characteristics at baseline. The phenytoin group had a higher number of falls compared to the other AED group (1.85 vs.0.73 falls, p-value<0.05). Utility scores over the follow-up visits were not significantly different. Conclusion: Exposure to an older AED can have an impact on the frequency of falls and the quality of life of nursing home patients. This has clinical and economic implications for the choice of AED therapy.