Antipsychotic drug use associated with urinary tract infections in older women

Abstract

OBJECTIVES: Antipsychotic drugs are frequently prescribed to elderly patients, but they are associated with serious adverse effects. The objective of the current study was to investigate the association between use of antipsychotics by elderly women and the risk of urinary tract infections (UTIs). COHORT STUDY SETTING: Dispensing data were obtained from the PHARMO Database Network for the period 1998-2008. PARTICIPANTS: Ambulatory Dutch women (≥65 years) with current and past use of antipsychotics. MEASUREMENTS: Incidence rates of UTIs, as defined by use of nitrofurantoin, was calculated within and outside the period of exposure to antipsychotic drugs. Cox proportional hazard regression analysis with Andersen-Gill extension for recurrent events was used to calculate crude and adjusted hazard ratios (HRs). RESULTS: During the study period, 18,541 women with a first prescription of an antipsychotic were identified. Current use of antipsychotics was associated with an increased risk of UTI compared to past use: HR, adjusted for age and history of UTIs, 1.33, 95% CI 1.27-1.39. A strong temporal relationship was found: the risk of being treated for a UTI was higher in the first week after the start of the treatment (adjusted HR 3.03, 95% CI 2.63-3.50) and decreased after 3 months (adjusted HR 1.22, 95% CI 1.17-1.28). Cumulative exposure was not associated with an increased risk of UTIs. There was no difference in effect between conventional and atypical antipsychotics. CONCLUSION: Our results show an increased risk of uncomplicated UTIs during antipsychotic use in older female patients, especially in the first week of treatment.