Adverse Drug Reactions to Gabapentin and Pregabalin A Review of the French Pharmacovigilance Database

Background Gabapentin and pregabalin are widely used as antineuropathic pain drugs. Their use is also associated with the development of adverse drug reactions (ADRs), mainly neuropsychiatric. Objective The aim of this work was to study 'serious' and/or 'unexpected' adverse reactions associated with pregabalin and gabapentin. Study Design We studied ADRs reported to the French Pharmacovigilance System occurring between 1995 and 2009. Main Outcome Measure For each ADR associated with gabapentin or pregabalin, we noted year, patient age and sex, type of adverse reaction, as well as the imputability score. Reporting rate of serious ADRs for gabapentin and pregabalin was estimated with regard to data of use (obtained from the French National Health Insurance Fund) using the defined daily dose. A global and descriptive analysis of the adverse reactions for each drug is presented. Secondly, details of deaths and ADRs with an imputability score of at least 'probable' or 'likely' were presented. Results Overall, 1333 cases were recorded (725 related to gabapentin, 608 related to pregabalin), mainly neuropsychiatric ADRs. Among the 22 deaths recorded, 8 were related to gabapentin in obstetrical situations. Other less well-documented ADRs were identified, such as hepatitis associated with gabapentin and haematological ADRs associated with pregabalin. Conclusion This study confirmed the prevalence of neuropsychiatric ADRs associated with gabapentin or pregabalin. A high rate of death occurred with gabapentin in an obstetrical context. New adverse reactions have been noted, such as haematological or hepatic adverse reactions associated with pregabalin and gabapentin, respectively.