Pharmaceuticals and vaccination for herpes zoster.
Shingles (herpes zoster, or HZ) is virtually synonymous with pain, whether it be from the rash itself, from postherpetic neuralgia (PHN), or postherpetic itch (PHI). Additionally, it can lead to serious complications involving the eye, including vision loss and blindness, as well as pneumonia, hearing problems, brain inflammation, and even death.
Treatment of the virus typically begins with antivirals—and the sooner the better. Acyclovir, valacyclovir, and famciclovir are most commonly used to treat shingles. They should be administered as quickly as possible after the onset of symptoms to shorten the severity and length of the illness.
Additionally, there are simple self-care steps that can be followed to help reduce the pain and discomfort of shingles.
Long-term nerve pain from PHN is the most common complication of shingles and is experienced by up to 20% of patients with shingles The risk of PHN increases with age, as does the severity and length of pain, which can persist for months or even years.
The FDA has approved the use of analgesics, anticonvulsants, and lidocaine and capsaicin topical patches for treating PHN.
“There is clear medication for postherpetic neuralgia, but just like everything else in the elderly it has more side effects and it doesn’t truly get rid of all the pain,” Jeffrey Cohen, MD, Chief, Laboratory of Infectious Diseases at the National Institute of Allergy and Infectious Diseases told Drug Topics®. “It’s not like the medicine causes the pain to completely go away. It makes it more tolerable.”
PHI, which can occur in conjunction with PHN, is caused by sensory fibers in the nerves that were damaged or died during the shingles infection. The remaining isolated nerve fibers fire when they shouldn't, generating false sensations that fool the central nervous system.
“What’s most important is drugs that dampen neuronal firing, like sodium channel blockers like tricyclics. The best treatment is topical or injectable anesthetics,” said neurologist Anne Louise Oaklander, MD, director of the Nerve Unit at Massachusetts General Hospital.
Of course, the most effective way to prevent nerve pain associated with shingles is to prevent shingles itself through vaccination. The CDC notes that Shingrix, the only shingles vaccine available in the United States, offers strong protection from shingles and its complications
“Shingrix is more than 90% effective at preventing shingles and long-term nerve pain,” the CDC points out. Short-term adverse effects (AEs) like a sore arm, redness and swelling at the injection site, fatigue, and muscle pain are due to the strong response Shingrix causes in the immune system.
Although persistent pain from shingles can last a lifetime, the AEs from Shingrix typically last just a few days. “A lot of people think, ‘Why should I get the shingles vaccine if it’s just going to keep me from getting this rash that’s going to be nasty for a few days?’” said Cohen. “You hear that Shingrix does have side effects, but I would take those side effects any day to prevent postherpetic neuralgia.”