Gabapentin and pregabalin are used in certain epilepsies and for pain in neurological diseases. Pregabalin is also used to treat anxiety disorders.

According to a review of French pharmacovigilance data published in 2013, between 1995 and 2009, 2415 adverse effects linked to gabapentin or pregabalin were recorded in the French pharmacovigilance database.

The most frequently reported adverse effects both for gabapentin and pregabalin were neuropsychological disorders including drowsiness, giddiness, agitation and aggressive behaviour towards others, confusion and hallucinations.

A total of 13 deaths were associated with these drugs: 8 patients exposed to gabapentin and 5 exposed to pregabalin. In 9 cases, exposure in utero was followed by the death of the newborn or the fetus.

The most frequently reported severe adverse effects were hepatic, with gabapentin (including fulminant hepatitis), and blood disorders with pregabalin (decrease in the number of white blood cells, blood platelets, etc.).

Other adverse effects were reported, including skin and immuno-allergic disorders, especially with gabapentin; cardiorespiratory disorders with gabapentin and pregabalin; oedema, gastrointestinal and renal disorders.

It is advisable to avoid exposing patients to these risks other than in situations where gabapentin or pregabalin have proved highly effective. It is preferable to inform patients to ensure that they report any adverse effects linked to the treatment.

©Prescrire 1 November 2014

"Gabapentin and pregabalin: sometimes serious hepatic and haematological toxicity" Prescrire Int 2014; 23 (154): 267. (Pdf, subscribers only).