From the Guidelines
Neuropathic pain in varicella zoster, also known as postherpetic neuralgia (PHN), is best treated with a multimodal approach, prioritizing early antiviral therapy and first-line medications such as gabapentinoids, tricyclic antidepressants, or serotonin-norepinephrine reuptake inhibitors. The varicella zoster virus can reactivate, causing herpes zoster and potentially leading to PHN, a complication characterized by persistent pain weeks to months after resolution of the rash 1.
Treatment Approach
The treatment approach for PHN typically involves a combination of medications, including:
- Gabapentinoids (gabapentin 300-1200 mg three times daily or pregabalin 150-300 mg twice daily)
- Tricyclic antidepressants (amitriptyline 10-75 mg at bedtime)
- Serotonin-norepinephrine reuptake inhibitors (duloxetine 30-60 mg daily or venlafaxine 75-225 mg daily) Topical treatments like lidocaine 5% patches or capsaicin 8% patches can provide localized relief 1.
Antiviral Therapy
Early antiviral therapy during acute herpes zoster can reduce the risk of developing PHN, with options including acyclovir 800 mg five times daily, valacyclovir 1000 mg three times daily, or famciclovir 500 mg three times daily for 7 days 1. High-dose IV acyclovir is recommended for immunocompromised hosts, while oral acyclovir, famciclovir, and valacyclovir can be used for mild cases in otherwise healthy hosts 1.
Prevention
Prevention of varicella and herpes zoster through vaccination is also crucial, especially for adults and immunocompromised individuals 1. The most effective strategy to prevent varicella, HZ, and its related complications is by vaccination, which can reduce the risk of developing PHN and other complications 1.
Key Considerations
Key considerations in the management of PHN include:
- Early recognition and treatment of herpes zoster to reduce the risk of PHN
- Multimodal treatment approach, including medications and topical treatments
- Prevention of varicella and herpes zoster through vaccination
- Individualized treatment plans, taking into account the patient's medical history, comorbidities, and potential interactions with other medications.
From the FDA Drug Label
The efficacy of pregabalin for the management of postherpetic neuralgia was established in three double-blind, placebo-controlled, multicenter studies These studies enrolled patients with neuralgia persisting for at least 3 months following healing of herpes zoster rash and a minimum baseline score of greater than or equal to 4 on an 11-point numerical pain rating scale ranging from 0 (no pain) to 10 (worst possible pain).
Neuropathic pain in varicella zoster can be managed with pregabalin, as the drug has been shown to be effective in treating postherpetic neuralgia, a condition that occurs after the healing of herpes zoster rash. The studies demonstrated that pregabalin statistically significantly improved the endpoint mean pain score and increased the proportion of patients with at least a 50% reduction in pain score from baseline 2.
From the Research
Neuropathic Pain in Varicella Zoster
- Neuropathic pain is a common complication of varicella zoster, also known as shingles, which is caused by the reactivation of the varicella-zoster virus 3.
- Postherpetic neuralgia (PHN) is a chronic neuropathic pain condition that persists 3 months or more following an outbreak of shingles 4.
- PHN is associated with persistent and often refractory neuropathic pain, and patients may experience multiple types of pain, including constant deep, aching, or burning pain, paroxysmal, lancinating pain, hyperalgesia, and allodynia 4.
Treatment Options
- The pharmacological treatment of PHN may include a variety of medications, such as alpha-2 delta ligands (gabapentin and pregabalin), other anticonvulsants (carbamazepine), tricyclic antidepressants (amitriptyline, nortriptyline, doxepin), topical analgesics (5% lidocaine patch, capsaicin), tramadol, or other opioids 4.
- Gabapentin has been shown to be effective in reducing pain, improving sleep, and improving some parameters on the Short Form-McGill Pain Questionnaire in patients with PHN 5.
- Antiviral therapy, started early in the course of disease, can significantly reduce the risk and the duration of postherpetic neuralgia in elderly patients 6.
- The combination of antiviral therapy and adequate pain management should be given to all elderly patients as soon as herpes zoster is diagnosed 6.
Prevention
- The best approach to managing PHN is to prevent the complication from occurring in the first place by preventing HZ with the HZ vaccine 7.
- The HZ vaccine has been shown to decrease the burden of illness caused by VZ and the incidence of HZ, but the uptake for the HZ vaccine is very low, and more patients over the age of 50 years should be encouraged to receive the vaccine 7.