Pregabalin and transcutaneous electrical nerve stimulation for postherpetic neuralgia treatment

OBJECTIVE: Postherpetic neuralgia (PHN) is responsible for one of the most common types of neuropathic pain, described as a burning pain that shakes, hits, and tightens and includes allodynia and paresthesia. AIM OF THE STUDY: To evaluate the efficacy of Pregabalin when used during transcutaneous electric nerve stimulation (TENS) in patients with PHN and to analyze any changes in physical activity and sleep quality. METHODS: Patients aged 50 to 80 years were included in this randomized study. We enrolled 15 male (average age 65+/-8.6 y) and 15 female patients (average age 64+/-8.2 y). The male patients had a history of neuropathic pain lasting 15.6+/-8.8 months whereas the female patients had a history of neuropathic pain lasting about 14.9+/-8.6 months. We began with 1 week of patient screening followed by a week of Pregabalin titration. Then, we established the dose of Pregabalin for each patient to obtain visual analog scale (VAS) of less than 60 mm. The eligible patients were randomly divided into 2 groups receiving Pregabalin + TENS or Pregabalin+TENS placebo for the following 4 weeks. Patients underwent 8 outpatient visits during which they completed VAS, SF-McGill Pain Questionnaire, and sleep interference questionnaire. RESULTS: The resulting data showed that Pregabalin administration associated with TENS reduced pain in patients with PHN. At the end of the treatment, all the observed groups presented a reduction of mean VAS. The group treated with Pregabalin 300 (P300)+TENS had a reduction of pain of 30% and the group treated with Pregabalin 600 (P600)+TENS had a reduction of pain of 40%. The comparison between group P300+TENS versus group P300+TENS placebo showed a statistically significant reduction of VAS (P300+TENS 25+/-0.67 vs. P300+TENS placebo 39+/-1.19 P<0.02). Moreover, the comparison between group P600+TENS versus group P600+TENS placebo has shown a statistically significant reduction of VAS (P600+TENS 23+/-0.78 vs. P600+TENS placebo 32+/-0.81 P<0.02). At the end of the study, all groups showed a statistically significant difference in terms of sleep interference, Short-Form McGill Pain Questionnaire total score, and Short-Form McGill Pain Questionnaire Present Pain Intensity. CONCLUSIONS: These data support the conclusion that Pregabalin gives better results when combined with TENS therapy, which is an analgesic nonpharmacologic procedure. Therefore, a multidisciplinary treatment should be considered for this kind of pain.