Double-blind, placebo-controlled clinical trial of a mixture of gangliosides ('Cronassial') in post-herpetic neuralgia.

A double-blind, parallel-group clinical trial was carried out in 25 patients with post-herpetic neuralgia to determine the efficacy and tolerability of a mixture of gangliosides ('Cronassial') compared with placebo. Patients were allocated at random to receive treatment with either 'Cronassial' (100 mg in 2 ml buffered solution) or placebo given by 11 subcutaneous injections over a period of 27 days, and their symptoms assessed on entry and after 2, 4 and 8 weeks. The four aspects of pain considered (overall pain, hyperaesthesia, stabbing pain and constant ache) all showed maintained reductions in severity with 'Cronassial' treatment, but not with placebo. In the case of hyperaesthesia, this difference between treatments was statistically significant (both during and after the course of injections), even with the relatively small number of patients in this study. Sleep patterns showed significant sustained improvements with 'Cronassial', but not with placebo treatment. Other psychological assessments (general psychological state, appetite and mood) showed little difference between 'Cronassial' and placebo treatment. Although 'Cronassial' was well tolerated systemically, 1 of the 12 patients was withdrawn because of general malaise, and 5 patients had local pain at the injection sites. Two of these 5 patients were withdrawn from the study. There were no withdrawals in the placebo group. It is suggested that further studies employing greater numbers of patients should be carried out to confirm the efficacy of gangliosides in improving symptoms of patients with post-herpetic neuralgia.