PHARMACOEPIDEMIOLOGYAND PRESCRIPTION Intensive monitoring of duloxetine: results of a web-based intensive monitoring study

Purpose Duloxetine (Cymbalta) is a serotonin (5-HT) and norepinephrine (NE) re-uptake inhibitor indicated for the treatment of depression, diabetic peripheral neuropathic pain and general anxiety disorder. The aim of this study is to gain insight in the user and safety profile of duloxetine in daily practice, reported by patients via a web-based intensive monitoring system during their first 6 months of use. Methods First-time users of duloxetine were identified through the first dispensing signal in the pharmacy. Patient demographics and information about drug use and adverse drug reactions, ADRs, were collected through electronic questionnaires sent 2 and 6 weeks, 3 and 6 months after the start of duloxetine administration. ADRs were quantified and signal detection was performed on a case by case basis. Results Three hundred and ninety-eight patients registered for the study; 69.1 % were female. Depression was the main indication. Three hundred and three patients (76.1 %) filled in at least one questionnaire and 78.9 % of these reported an ADR. Serious ADRs were reported by 4 patients. Three new signals were identified, amenorrhea, shock-like paraesthesias and micturition problems. Conclusions Web-based intensive monitoring is an observational prospective cohort study mirroring the use and ADRs of duloxetine in daily practice. This study indicates that duloxetine is a relatively safe drug as used by patients for six months in daily practice, but the aforementioned signals need to be evaluated in more detail.