Pain control in trigeminal neuralgia (TN) is achieved using anticonvulsivants, mainly carbamazepine. When this drug cannot be used, other drugs like gabapentin (GBP) have been used to provide adequate pain control. To improve the therapeutic effect of GBP, we evaluated the clinical efficacy of associating GBP with ropivacain (ROP) analgesic block of facial trigger points in TN patients.
Thirty-six TN patients were randomly assigned during 4 weeks to 1 of the following protocols: Protocol I-daily oral GBP administered in a titrated dose; Protocol II-ROP applied as analgesic block to TN trigger points once a week; Protocol III-daily oral GBP plus ROP once a week. Protocol II had to be discontinued in 7/12 patients owing to insufficient pain control. Pain intensity was evaluated by the Visual Analog Scale (VAS) and disability was assessed by Sickness Impact Profile.
When compared with Protocol I, Protocol III (GBP+ROP) patients showed (1) a reduction of VAS score after 7 and 28 days of treatment, an effect that was still present 6 and 12 months later; (2) a faster reduction of VAS score using a significantly lower dose of GBP; (3) a smaller total and daily GBP dose at the end of the treatment, which resulted in a total absence of adverse side effects; and (4) an improvement of the functional well-being measured by the Sickness Impact Profile. The number needed to treat (NNT) (GBP+ROP vs. GBP protocols) to obtain 1 GBP+ROP-treated patient with at least 50% pain relief was 1.71 (day 7) and 2.40 (day 28).
The association of GBP and ROP is safe, without side effects and results in an important clinical benefit associated to an improvement of the functional health status of TN patients when compared with GBP alone. This may constitute a therapeutic alternative for pain control in TN patients who cannot be treated with carbamazepine.