Non‐antiepileptic drugs for trigeminal neuralgia
Abstract
Background
Non‐antiepileptic drugs have been used in the management of trigeminal neuralgia since the 1970s.
Objectives
The objective was to systematically review the efficacy and tolerability of non‐antiepileptic drugs for trigeminal neuralgia.
Search methods
For this updated review we searched the Cochrane Neuromuscular Disease Group Specialized Register (30 April 2010). We also searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 2), MEDLINE (January 1966 to April 2010), EMBASE (January 1980 to April 2010), LILACS (January 1982 to April 2010) and the Chinese Biomedical Retrieval System (1978 to April 2010). We handsearched 10 Chinese journals.
Selection criteria
We searched for double‐blind randomized or quasi‐randomized controlled trials in which the active drug was used for at least two weeks.
Data collection and analysis
Two authors decided which trials fitted the inclusion criteria and independently graded risk of bias.
Main results
Four trials involving 139 participants were included. The primary outcome measure in each was pain relief. Three trials with an unclear risk of bias compared one of the non‐antiepileptic drugs tizanidine, tocainide or pimozide with carbamazepine. In a trial of tizanidine involving 12 participants (one dropped out due to unrelated disease) one of five treated with tizanidine and four of six treated with carbamazepine improved, risk ratio 0.30 (95% CI 0.05 to 1.89). Few side effects were noted with tizanidine. In a study involving 12 participants there was an improvement in mean pain scores with tocainide similar to that with carbamazepine, but significant side effects limited its use. In the pimozide study more participants improved on pimozide (48/48) than with carbamazepine (27/48) (risk ratio 1.76, 95% CI 1.37 to 2.26). Up to 83% of participants reported adverse effects but these did not lead to withdrawal from the study. A trial with low risk of bias involving 47 participants compared 0.5% proparacaine hydrochloride eyedrops with placebo but did not show any significant benefits or side effects.
Authors' conclusions
Of the four studies identified, one had low and three an unclear risk of bias. There is insufficient evidence from randomized controlled trials to show significant benefit from non‐antiepileptic drugs in trigeminal neuralgia. More research is needed.
PICOs
Plain language summary
Drugs other than those used for epilepsy for treating trigeminal neuralgia
Trigeminal neuralgia is a condition that affects the trigeminal nerve, the nerve which provides the sensory innervation of the skin on the face. The condition causes a sudden, severe, stabbing facial pain near the nose, lips, cheek, eye or ear. The incidence of trigeminal neuralgia is three to five new cases per 100,000 people each year. Non‐antiepileptic drugs, such as baclofen and tocainide, have been used to treat trigeminal neuralgia since the 1970s.
Three randomized controlled trials, each with an unclear risk of bias, compared the three different non‐antiepileptic drugs tizanidine, tocainide and pimozide with carbamazepine, which is the standard drug treatment. Tizanidine and tocainide did not produce significantly more benefit than with carbamazepine. Tocainide had severe side effects. Pimozode produced significantly more improvement than carbamazepine but side effects were very common. In a fourth trial with a low risk of bias proparacaine hydrochloride eye drops did not show any significant benefit.
Further well designed randomized controlled trials are needed to establish whether non‐antiepileptic drugs are beneficial in trigeminal neuralgia.
