Non-antiepileptic drugs for trigeminal neuralgia.

BACKGROUND: Non-antiepileptic drugs have been used in trigeminal neuralgia management since the 1970s.

OBJECTIVES: The objective was to review systematically the efficacy of non-antiepileptic drugs for trigeminal neuralgia.

SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Register, MEDLINE, EMBASE, and LILACS (all to August 2005) and the Chinese Biomedical Retrieval System, the database of the Chinese Cochrane Center (The Cochrane Library, Issue 1 2005), conference paper databases and checked bibliographies. We handsearched ten Chinese journals.

SELECTION CRITERIA: We searched for randomized or quasi-randomized controlled trials.

DATA COLLECTION AND ANALYSIS: Two authors decided which trials fitted the inclusion criteria and graded methodological quality independently.

MAIN RESULTS: Nine trials of different non-antiepileptic drugs involving 223 participants were included. Each trial investigated one non-antiepileptic drug. Two trials tested baclofen. In one, more people gained 50% reduction from baseline than with placebo (relative risk 15.00, 95% CI 0.97 to 231.84, P value = 0.05). In the other, slightly more participants on baclofen had a 75% reduction in attacks on the 10th day compared with carbamazepine (relative risk 2.38, 95% CI 0.83 to 6.85, P value = 0.11). One trial showed no significant difference in reduction in average daily frequency of attacks with L-Baclofen compared with racemic baclofen. Tizanidine was investigated in two trials. In one, the proportion of people with reduction in the average number of paroxysms per day increased with tizanidine compared with placebo (relative risk 8.00, 95% CI 1.21 to 52.69, P value = 0.03). In the other, one of five participants improved in visual analog scale score with tizanidine and four of six with carbamazepine (relative risk 0.30, 95% CI 0.05 to 1.89, P value = 0.20). One study showed that the improvement in mean values of pain scores with tocainide was similar to that of carbamazepine. In one study more participants improved during the pimozide than the carbamazepine period (relative risk 1.78, 95% CI 1.39 to 2.28). In one study, proparacaine hydrochloride 0.5% instillation into the eyes was not significantly different from placebo (relative risk 1.06, 95% CI 0.37 to 2.99, P value = 0.92). In another, there was moderate or marked improvement in seven of nine participants treated with clomipramine and three of nine with amitriptyline after a 12-week treatment (RR 2.33, 95% CI 0.87 to 6.27).

AUTHORS' CONCLUSIONS: There is insufficient evidence from randomized controlled trials to show significant benefit from non-antiepileptic drugs in trigeminal neuralgia. More research is needed.