OBJECTIVES: Impact of pharmacovigilance (PV) actions such as marketing authorisation (MA) withdrawal on public health is not normally measured quantitatively. Removing medicines from market may reduce adverse drug reactions (ADRs) significantly affecting public health (PH), which should be measured quantitatively if possible. This study identified a method to quantify impact of MA withdrawal in terms of morbidity and mortality changes. Almitrine's MA withdrawal throughout France (2013) due to cases of peripheral nervous system (PNS) disturbance and severe weight loss, demonstrates the model.

METHODS: Patients exposed to almitrine were counted in quarterly periods for 12 months pre- and post-MA withdrawal, in IQVIA Medical Research Data (IMRD)-France electronic health record database; annual exposure was estimated. Reason for MA withdrawal (ADR of interest) was obtained from EMA records. Quantitative research addressing the ADR of interest was identified by systematic review, allowing an estimation of absolute risk in exposed patients. PH impact of PV action, expressed as crude annual prevention of ADRs, was estimated by modelling product usage figures and ADR risk.

RESULTS: At the time of almitrine's withdrawal, 7,456,368 patients were active in IMRD-France. Prevalence of almitrine exposure during the 12 months before withdrawal was 0.82 per 100,000 IMRD-France patients. Exposure to almitrine decreased by 51.9% in the population after its withdrawal, but some exposure remained after 12 months. Risk of PNS disturbance was 15.5% and severe weight loss was 7.8%, estimated from published studies. Based on risk and usage, withdrawal of almitrine from market could prevent up to 13 cases of PNS disturbance and 3 cases of severe weight loss annually amongst IMRD-France patients if exposure were eliminated.

CONCLUSIONS: This model quantifies PH impact of almitrine’s MA withdrawal in terms of serious morbidity, assuming exposure was eliminated. This method can be applied to other products in a range of settings.