- 医療薬学 (ISSN:1346342X)
- vol.40, no.5, pp.310-316, 2014-05-10 (Released:2015-05-10)
A retrospective survey of a database containing patient backgrounds and prescribed drugs was conducted to elucidate the detailed characteristics and risk factors of adverse effects caused by topical dermatological formulations of diclofenac. A total of 145,478 patients who had been dispensed topical dermatological formulations of diclofenac at 466 community pharmacies belonging to Nihon Chouzai were included in the study. Of these, 580 patients had adverse effects. The incidence of adverse effects was significantly higher in the elderly (more than 65 years old) and in female patients. A variety of systemic adverse effects were evident in 19 patients. Approximately half of these adverse effects were related to the respiratory system, eg, asthma, but the other adverse effects (eg, edema, decreases in urinary volume, tremor and others) were not described in the drug package inserts. Data from patients with systemic adverse effects, and an age- and gender-matched control group of patients underwent multivariate logistic regression analysis. Asthma (odds ratio: 13.3, 95% confidence interval: 2.40 - 95.5, P = 0.004) and the number of co-administered drugs (odds ratio: 1.25, 95% confidence interval: 1.02 - 1.55, P = 0.035) were identified as risk factors for systemic adverse effects of topical dermatological formulations of diclofenac. Moreover, many of the co-administered drugs affected P450 enzymes other than P450 2C9, the main metabolizer of diclofenac. Therefore, to manage the risk of adverse events, it was concluded that various characteristics of concomitant medications and patient's medical history should be evaluated properly before topical dermatological formulations of diclofenac are prescribed.