Pregabalin can be chosen as the 1st line treatment for postherpetic neuralgia

Postherpetic Neuralgia

Postherpetic neuralgia is a subset of neuropathic pain. Due to the reactivation of the varicella zoster virus in the spinal ganglia or cranial nerve ganglia, a characteristic rash appears in the corresponding dermatome, accompanied by localized pain. If the pain persists for more than 3 months after the rash disappears, it is referred to as postherpetic neuralgia. Its management often requires combination therapy. First-line drugs currently include tricyclic antidepressants, antiepileptics gabapentin and pregabalin, and lidocaine patches. In case of insufficient efficacy, the treatment is supplemented with second-line drugs (opioids and capsaicin patches), or third-line drugs (other antiepileptics, opioids, NMDA antagonists). 

Efficacy of Pregabalin

Pregabalin blocks the release of excitatory neurotransmitters by binding to the subunit of the voltage-gated calcium channel. It is used to treat neuropathic pain, epilepsy, and generalized anxiety disorder. Its efficacy in patients with postherpetic neuralgia has been demonstrated in 4 multicenter randomized double-blind placebo-controlled studies lasting 4−13 weeks.

Pregabalin, administered in a dosage range of 150–600 mg per day, divided into 2−3 doses, significantly better affected pain compared to placebo, and this effect was dose-dependent. Positive results were shown not only in the degree of pain reduction but also in the duration of use that led to pain relief. The effect in the pregabalin-treated study groups occurred within 1.5–3.5 days, whereas in the placebo groups it took more than 4 weeks. The proportion of patients experiencing a 30% or 50% reduction in pain was also significantly higher with pregabalin compared to placebo. Pregabalin also limited the negative impact of pain on sleep.

Tolerability and Adverse Effects

In studies predominantly involving older patients (mean age 67–73 years), pregabalin was well tolerated. The most common adverse events were a sense of instability, drowsiness, peripheral edema, headaches, dry mouth, weight gain, and ataxia. Treatment discontinuation due to drug intolerance was dose-dependent in most studies, with more pronounced differences between lower and higher doses observed with a 3× daily dosing regimen compared to a 2× daily regimen.

Conclusion

The results of the studies demonstrate the efficacy of pregabalin in the treatment of postherpetic neuralgia and support its inclusion in the first line of treatment for this condition.

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Source: McKeage K., Keam S. J. Pregabalin. Drugs Aging 2009; 26 (10): 883–892, doi: 10.2165/11203750-000000000-00000.