[Long-term treatment with oral ketamine. Case report of a female patient with therapy-resistant post-herpetic neuralgia].

Postherpetic neuralgia can lead to therapy-resistant neuropathic pain. We report the case of a 74-year-old woman with postherpetic perineal neuralgia resistant to opioids and antiepileptic drugs who has been successfully treated with oral ketamine for 28 months. Pain scores were reduced by more than 50%, despite dose reduction of other analgetic drugs. Significant side effects have not yet been reported. Despite "off-label" use, ketamine is an important third line option in cases of therapy-resistant neuropathic pain.