Slow-release formula reduces side effects

Changing to slow-release carbamazepine could be a ‘worthwhile strategy’ in patients with acceptable seizure control on immediate-release carbamazepine but with unacceptable adverse events, a review finds. “When carbamazepine is absorbed into the body quickly, peaks in blood levels may cause side effects such as dizziness, drowsiness and lack of coordination,” the study authors wrote. Of ten trials analysed in the Cochrane Review, they found a favourable trend for fewer adverse events when patients used a slow-release formulation (CR CBZ) of the drug. Eight trials focused on adverse events from both medications, of which four found a significantly reduced incidence of adverse events in patients taking CR CBZ compared to immediate-release carbamazepine formulation (IR CBZ). A further two trials reported a lower incidence of side effects with CR CBZ that did not reach statistical significance, and one other trial found no difference. Of eight trials that measured seizure frequency patients, there was no difference between formulations. “This narrative analysis suggests a reduced incidence of adverse events and therefore superiority of CR CBZ compared to IR CBZ when considering adverse events,” the authors wrote. “However, for trials involving epilepsy patients already prescribed IR CBZ, no conclusions can be drawn concerning superiority with respect to seizure frequency.” They noted that the results do not provide “robust evidence” due to the heterogeneous methods and risk of bias in many of trials included in the review. “Nevertheless, in patients currently prescribed IR CBZ and experiencing unacceptable dose-related adverse events, changing to CR CBZ may be worthwhile and should be considered by the clinician when faced with this scenario,” they concluded. Cochrane Database of Systematic Review 2010, Issue 1. CD007124...