FDA Expands Indication of Antiviral Therapy to Include Post-Exposure Influenza Prevention
November 23, 2020 09:45pm
Herpes zoster, or shingles, is unfortunately quite common in community settings, despite the availability of a preventive vaccine.
Herpes zoster, or shingles, is unfortunately quite common in community settings, despite the availability of a preventive vaccine. Patients—usually in their senescence or immunocompromised—generally seek treatment because they experience excruciating pain. The pain creates sleep disturbances, saps energy, and causes worry and anxiety. Left untreated, the pain may continue and become postherpetic neuralgia (PHN).
Although most cases of herpes zoster will resolve without intervention, patients who develop shingles will need and want medication. Retail health care providers need to be aware of the parameters within which they can prescribe antivirals and pain medications. The likelihood is that when faced with these patients, clinicians will need to consider the potential for medication interactions and possible organ impairment.
Patients may find that applying dressings saturated with 5% aluminum acetate (Burow’s solution) for 30 to 60 minutes up to 6 times daily will soothe some of the lesions. Patients can purchase Domeboro®astringent solution powder packets OTC, but they will need some guidance about how to reconstitute the powder. Calamine lotion may reduce itching.
Step Up to Prescription Drugs
Antiviral prescriptions, all of which are nucleoside analogues, are most effective if initiated within 72 hours of the appearance of lesions. Some studies indicate that they may be useful even after 72 hours, but the research is not definitive. Antivirals are clearly indicated if the patient has lesions along 2 or more dermatomes, in or near the eyes, or over a large area of the body. They can expedite lesion healing, decrease viral shedding, and decrease pain. Retail healthcare providers should advise patients that antivirals will not prevent PHN.
Oral famciclovir and valacyclovir are now preferred over acyclovir. Both of these antivirals are given 3 times daily for a week, which is an improvement over acyclovir’s 5-times daily dosing schedule. Immunocompromised patients may need longer durations of therapy. Retail health care providers should note that some acyclovir-resistant viral strains have been identified.
Patients who take these drugs may develop nausea, vomiting, headache, central nervous system disturbances, or dizziness. Therefore, those antivirals may be contraindicated in patients who have depression are cognitive impairment. All of these antivirals are excreted through the kidneys. Dose reductions will be needed in patients who have renal impairment, and retail health care providers should encourage patients to hydrate adequately. Patients who run renal dialysis should be advised by retail health care providers to take their dose after treatment.
Some prescribers use corticosteroids in short doses to reduce inflammation and pain.
Treating Herpetic Pain
Patients often need analgesics to deal with herpes zoster pain. In our elderly population, the “start low, go slow” approach is usually best. Increasing analgesic doses slowly often leads to an optimal dose with which pain is controlled and adverse effects are minimized.
· Patients may find nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen helpful for mild pain. Prescribers must exercise care in patients who have cardiovascular disease or impaired renal function when they prescribe NSAIDs. And, of course, NSAIDs are associated with gastrointestinal upset and ulceration. A history of GI bleed or ulceration is not an absolute contraindication, but providers should prescribe these drugs with caution.
· Opioids may be warranted in this case although retail health care providers should prescribe them care and provide quantities only sufficient to cover short periods. Constipation is a critical concern, especially in elderly patients, and retail health care providers should prescribe a concurrent high-fiber diet, stool softeners, and laxatives.
· Antiepileptic drugs and tricyclic antidepressants can be used as adjunct analgesics. Many of these also cause drowsiness, so patients will need to be warned. Gabapentin and pregabalin are used often and, likewise, will need adjustment in renal impairment.
Managing Patient Expectation
It’s critical to tell patients that if they develop lesions near or on their eyes, then they must return for referral to an ophthalmologist immediately. It’s also important to stress that they need to take the entire course of antiviral medication—even after they begin feeling better. It’s critical to manage patients’ expectations. That means explaining possible adverse effects and describing the usual course of the condition. It’s critical to manage patients’ expectations. The following is a guide to explaining possible adverse effects and describing the usual course of the condition.
Shingles: What to Expect
· Blistering, painful lesions will develop over a period of 1 to 2 weeks along at least one dermatome.
· Over the course of 2 to 4 weeks, the lesions will develop, and as they heal, they’ll crust over.
· Pain may present as pins-and-needles, itching, burning or as deep as possible.
· Some patients develop fever or muscle weakness:
o Until the lesions crossed over, this condition is contagious
o Patients should avoid contact with others who have not had chickenpox, and with especially pregnant women.
o Patients should keep skin clean, discard bandages carefully, and discard or wash clothing in hot water if it has come in contact with lesions.
Before ending a visit for shingles, retail health providers who review the patient’s entire medication regimen including their OTC medications and complementary and alternative medications do patients a great service. Often, patients are confused about what they are or should be taking, and spending a few minutes reviewing the regimen can prevent medication misadventure. A brief call to the patient’s pharmacist can also shed light on any vagaries.
Sleep disturbances can be one of the most troubling sequelae associated with shingles. Retail health care providers may prescribe opioids at bedtime, but patients will need counseling so that they don’t experience orthostatic hypotension or falls if they get up during the night.
And About That Vaccine…
Experiencing an episode of shingles boosts immunity to the virus and may be protective against future bouts of shingles, but some people develop shingles more than once. The CDC recommends the shingles vaccine for all adults ages 60 and older. Giving the vaccine at the same time as patients are receiving antiviral agents is unwise. Clinicians should wait at least 14 days after the patient has discontinued his or her antiviral regimen to administer the zoster vaccine.
Our elders should receive the vaccine whether or not they have had shingles. It’s important to counsel patients that the shingles vaccine is not 100% effective; some people who receive it will still develop shingles. If they do, the severity and duration of the condition is usually shorter than in unvaccinated individuals. The shingles vaccine is contraindicated in HIV-infected individuals, patients who are on immune system suppressing drugs or treatments, and patients who are pregnant.
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