Shingles (herpes zoster) can lead to postherpetic neuralgia, a chronic neuropathic pain condition characterized by burning, stabbing, or electric pain. This ongoing nerve pain can interfere with sleep, mood, and daily activities, especially when first-line treatments such as gabapentin, antidepressants, or topical therapies are ineffective.

Ketamine infusion therapy is used in select patients with severe, treatment-resistant postherpetic neuralgia to address central pain sensitization and abnormal nerve signaling.