What are the treatment options for postherpetic neuralgia (PHN)?

From the Guidelines

Postherpetic neuralgia is best treated with a combination of medications and non-pharmacological approaches, prioritizing gabapentin or pregabalin as first-line treatments due to their efficacy and safety profiles, as evidenced by a 2017 systematic review 1. The treatment approach should be individualized, considering the patient's medical history, comorbidities, and potential side effects.

• Oral gabapentin, typically starting at 300 mg three times daily, can be gradually increased to a maximum of 3600 mg daily divided into three doses.
• Alternatively, pregabalin can be used, starting at 75 mg twice daily and increasing to a maximum of 300 mg twice daily.
• For additional pain relief, topical lidocaine 5% patch can be applied to the affected area for up to 12 hours daily.
• If pain persists, consider adding a tricyclic antidepressant such as nortriptyline, which has been shown to have a superior side effect profile compared to amitriptyline 1, starting at 10-25 mg at bedtime and gradually increasing to 25-100 mg at bedtime as tolerated.
• Opioids like tramadol or oxycodone may be considered for severe, refractory pain but should be used cautiously due to the risk of dependence.
• Non-pharmacological treatments, such as transcutaneous electrical nerve stimulation (TENS) and capsaicin cream or patches, can also be considered. The goal of treatment is to reduce pain and improve quality of life, with regular follow-up essential to assess efficacy and adjust treatment as needed, as supported by the 2017 guideline for the management of chronic pain in patients living with HIV 1.

From the FDA Drug Label

The efficacy of gabapentin for the management of postherpetic neuralgia (PHN) was established in two randomized, double-blind, placebo-controlled, multicenter studies. The efficacy of pregabalin for the management of postherpetic neuralgia was established in three double-blind, placebo-controlled, multicenter studies In adults with postherpetic neuralgia, gabapentin may be initiated on Day 1 as a single 300 mg dose, on Day 2 as 600 mg/day (300 mg two times a day), and on Day 3 as 900 mg/day (300 mg three times a day).

Treatment options for postherpetic neuralgia (PHN) include:

• Gabapentin, which can be initiated at a dose of 300 mg on Day 1 and titrated up to 1800 mg/day 2
• Pregabalin, which has been shown to be effective in three double-blind, placebo-controlled, multicenter studies 3 Key considerations:
• Gabapentin dosing may need to be adjusted based on renal function 2
• Pregabalin dosing may also need to be adjusted based on renal function 3

From the Research

Treatment Options for Postherpetic Neuralgia (PHN)

• Medication therapies:
  • Tricyclic antidepressants 4
  • Pregabalin 4
  • Gabapentin, including immediate-release and extended-release formulations 5, 4, 6, 7, 8
  • Lidocaine patches 4
  • Tramadol and capsaicin creams and patches 4
• Interventional therapies:
  • Transcutaneous electrical nerve stimulation 4
  • Local botulinum toxin A, cobalamin, and triamcinolone injection 4
  • Intrathecal methylprednisolone and midazolam injection 4
  • Stellate ganglion block 4
  • Dorsal root ganglion destruction 4
  • Pulsed radiofrequency therapy 4
  • Peripheral nerve stimulation 4
  • Paravertebral block 4
  • Spinal cord stimulation 4

Gabapentin Formulations

• Immediate-release gabapentin (gabapentin three-times daily) 5, 6, 7, 8
• Once-daily gastroretentive gabapentin 5, 6, 8
• Extended-release gabapentin (gabapentin ER) 7
• Gabapentin enacarbil (GEn) 7

Efficacy and Safety of Gabapentin Formulations

• Gabapentin formulations have been shown to be effective in reducing pain associated with PHN 5, 6, 7, 8
• The once-daily gastroretentive formulation of gabapentin may have a better tolerability profile compared to the immediate-release formulation 5, 8
• Increasing the dose of gabapentin may not provide additional pain relief, but may increase the risk of adverse events 7