Background. Postherpetic neuralgia (PHN) is a difficult to treat pain syndorme affecting 10–15% patients with varicella zoster infection. The aim of the study was to determine the efficacy of PHN treatment with gabapentine and tramadol.
Material and methods. Fourteen patients with PHN aged 54.1 years (SD = 7.6) were included into the study. The mean time from regression of skin lesions was 25.8 months (SD = 16.0). All patients suffered form neurophatic pain located in 2–5 thorax dermatoms (average 3.4, SD = 0.7), the mean pain intensity was 7 points in Visual Analogue Scale (VAS). All patients were previously treated with carbamazepine. After 2 weeks of wash-out period, treatment with tramadol (200 mg/d) and gabapentine (100 mg/d) was initiated. Dosage of gabapentine was increased by 100 mg every day until effective dose was reached. The effectiveness of treatment was determined by assessment of VAS in 2, 3, 4 and 5 week of treatment.
Results. Daily effective dose of gabapentine was 900–2400 mg, mean 1475 mg (SD = 413). The mean intensity of pain during last examination was 2.58 in VAS (SD = 51) and the difference form the initial evaluation of pain intensity was - 4.42 points (SD = 0,9) and was statistically significant (p < 0.05). The dosage of gabapetnine correlated with the number of affected skin dermatomes (χ² = 32.0, p < 0.001). The treated group was small so the unexpectedly good results should undergo further investigation.
Conclusion. The use of gabapentine with tramadol in treatment of PHN gave good results. The effective dose of gabapentine may depend on the number of skin dermatoms affected with neuropatic pain.