1. An antiviral can hasten the resolution of the rash by several days. Relief of acute pain occurs two to three days after an antiviral is initiated. The duration of pain is reduced by about half. Antiviral therapy is more likely to be of benefit if initiated within 24 hours of rash onset.
2. Acyclovir (Zovirax)
a. 800 mg q4h while awake (5 times a day) for 7 days. [400, 800 mg tab].
c. IV acyclovir is reserved for the severely immunosuppressed (bone marrow transplant patients), disseminated infection, or ophthalmic zoster.
d. The IV dose for zoster is 10 mg/kg, administered over a one-hour, q8h. Nephrotoxicity can usually be avoided if the patient remains wellhydrated. The dosage should be reduced in renal failure.
3. Famciclovir (Famvir) is equally effective as acyclovir; it has a more convenient dosing interval; one 500-mg tablet tid for 7 days.
4. Valacyclovir (Valtrex), may be slightly more effective than acyclovir; 1,000 mg tid x 7 days [500 mg].
5. Foscarnet (Foscavir)is useful for acyclovir-resistant herpes infections.
6. Ophthalmic distribution zoster is a medical emergency which requires IV acyclovir and topical antivirals.
B. The incidence of PHN after an episode of herpes zoster is 5-50%. Those aged 60 and older have a 50% chance of developing PHN. PHN resolves within two months in about half of those affected.
C. Antivirals, aspirin, and acetaminophen are usually not effective for PHN.
D. Topical preparations
1. Capsaicin cream OTC (Zostrix, Zostrix-HP) 0.025% tid-qid reduces the pain. Ben-Gay, Flex-all 454 or Aspercreme may offer similar relief.
2. EMLA topical cream (lidocaine and prilocaine) qid may be useful.
3. Amitriptyline (Elavil) is often effective; 10-25 mg qhs, increasing in weekly increments of 25 mg as needed.
4. Gabapentin (Neurontin), 300 mg qd-tid, may be effective. Carbamazepine (Tegretol), 200 mg bid, has also been used.
5. Transcutaneous electrical nerve stimulation (TENS), lidocaine injections, nerve block injections, permanent nerve blocks with alcohol, and nerve resectioning have been used for recalcitrant cases.
References: See page 195.
Was this article helpful?