ABSTRACT

Post herpetic neuralgia is a most common complication of herpes zoster which is difficult to treat. Significant beneficial effects found when treated with antiviral, tricyclic antidepressant, anticonvulsive like gabapentine and pregabalin, opioid and non opioid analgesic etc. Primary prevention can also be done with vaccine. The aim of this randomized comparative study was to establish clinical efficacy with amitriptyline and pregabalin.

An open ended randomized clinical trial was conducted to compared clinical efficacy of amitriptyline (n=25) and pregabalin (n=25). Amitriptyline was given 25 mg once daily and pregabalin 75 mg twice daily. Total period of treatment were 6 month and patients were reviewed at the end of 2 months, 4 months and 6 months to evaluate the degree of improvement in pain perception and any adverse reaction.

Four types of patients were included in this study and among them thoracic type was the commonest (54%). It was followed by cervical (24%), trigeminal (16%) and lumbosacral types (6%). According to VAS score, satisfactory significant improvements in pain perception was observed at the end of 2 months (36%vs 8%, p<0.05) and 4 months (61.9%vs 27.8%, p<0.05) in pregabalin group than amitriptyline group. The chances of improvement more than 6 times and 4 times higher in patients with pregabalin group than those in amitriptyline group. There is no significant improvement difference was noticed at the end of 6months between groups. However, improvement was 89%(OR=1.89, 95% CI: 0.53-6.68) higher in pregabalin group than amitriptyline group. More importantly dizziness was the commonest side effect in pregabalin group while dryness of mouth was the commonest side affect in amitriptyline group.

In conclusion, therapy with pregabalin is better compare to amitriptyline in post herpetic neuralgia. However a similar study with larger augmentation is required to establish the findings.