Combination therapy of Gabapentin and Pregabalin for Postherpetic Neuralgia in 15 Patients

Abstract

PHN, a common sequela of herpes zoster, is a significant health concern, especially among the elderly. It is estimated that approximately 65% of patients above 60 years old develop PHN, and up to 75% of individuals with herpes zoster over 70 years old may develop PHN. While several drugs have been found effective, the numbers needed to treat for these drugs is over 6. Many patients still experience inadequate pain relief. Combination therapy is often considered when adequate pain relief is not achieved. Gabapentin is sometimes combined with pregabalin for PHN treatment and this therapy is not recommended by relevant treatment guidelines. We conducted a retrospective analysis of medical records of PHN patients who received combination therapy with gabapentin and pregabalin at our hospital. Data collected included numeric rating scale (NRS) pain scores before and after combination therapy, as well as the duration of each therapy. Statistical analysis was performed using SPSS software. A total of 15 patients were included in this study. The mean NRS score before combination therapy was 4.40±1.35, which decreased significantly to 2.20±1.30 post-treatment (p=0.001). The duration of combination therapy was comparable to that of monotherapy. One patient reported adverse reactions following the switch to combination therapy. For PHN patients who do not respond adequately to monotherapy, combining gabapentin and pregabalin is a viable option. However, larger studies with randomized controlled trials are needed to further validate the finding.