Give analgesics for shingles pain
Many clinical trials have looked at the efficacy of different analgesics in the treatment of PHN, but data regarding analgesics for the treatment of acute HZ pain are limited. One RCT of 87 patients older than 50 divided participants into 3 groups: One group took controlled-release oxycodone, another received a placebo, and the third group took gabapentin.21 (The study did not include patients with mild pain, for whom nonnarcotic analgesics would likely be more appropriate.)
The researchers found that the oxycodone significantly reduced acute HZ pain during the first 2 weeks of treatment as compared with placebo or gabapentin. There was no statistically significant reduction in pain for the gabapentin group, compared with those on placebo. The oxycodone group did have the highest dropout rate (27.6% vs 6.9% for the placebo group), however, primarily because of constipation. This study showed that narcotic analgesics are effective and relatively well tolerated for the treatment of acute HZ pain.21
Because severe pain with acute HZ is a well-established risk factor for the development of PHN, there is interest in determining whether effective pain control in the acute setting decreases the risk of chronic pain. One placebo-controlled trial of 72 patients older than 60 years found that 25 mg amitriptyline daily, started within 48 hours of rash onset and continued for 90 days, reduced pain prevalence by more than half at 6 months from diagnosis.22 This study did not control for the use of antiviral agents, however, so further investigation is needed.
CASE Jane T began a course of antiviral therapy with valacyclovir shortly after her rash appeared, and continued to take oral tramadol for the pain. Her rash and pain level improved over the next several days, and within 2 weeks she was fully recovered.
Prevention: Vaccination holds the key
HZ is contagious and can cause primary varicella in people who are susceptible. Indeed, one study found that 15.5% of susceptible household contacts developed varicella after exposure to HZ.1 Advise patients with HZ to avoid contact with those at high risk for severe varicella—including pregnant women, premature infants, and immunocompromised individuals of all ages—until their lesions are crusted. They can further avoid transmission by keeping the lesions covered.23
Increased use of the HZ vaccine, however, is the key to prevention of shingles. The Centers for Disease Control and Prevention (CDC) recommends Zostavax, a live attenuated varicella zoster vaccine given as a single subcutaneous injection, for people ages 60 and older. Compared with the varicella vaccines designed for children, Zostavax has a significantly higher potency in order to elicit a significant and durable response in older adults.24
The vaccine is generally safe, with a mild injection site reaction being the most common adverse event. No evidence exists of transmission of virus from vaccine recipients to contacts.1 Like other live virus vaccines, Zostavax is contraindicated in pregnant women and immunocompromised patients. It can be given to patients regardless of their history of chicken pox or previous episodes of HZ, as studies have shown that the recurrence rate for HZ is similar to the rate for initial episodes.
How well does it work? In a Shingles Prevention Study Group trial of 38,546 people 60 years of age or older, the vaccine reduced the incidence of HZ by 51% and the incidence of PHN by 67% over a 3-year follow-up period.25 The vaccine was most effective for the prevention of HZ in the 60- to 69-year age group, but there was no significant difference in its efficacy in preventing PHN or reducing the burden of illness (a measure based on the incidence, severity, and duration of pain and discomfort) in 60- to 69-year-olds vs those ages 70 and older.25 An analysis by the CDC suggests that approximately 17 people would need to be vaccinated with Zostavax to prevent one case of HZ, and approximately 31 people would need to be vaccinated to prevent one case of PHN.24
Ongoing studies are examining the safety and efficacy of Zostavax for patients ages 50 to 59.26 Although results thus far look promising, there is no recommendation for routine vaccination for this age group, and insurance companies do not routinely cover the cost of vaccinating them.
While primary care physicians generally favor the concept of HZ vaccination,27 a CDC survey conducted in 2007—a year after the vaccine received FDA approval—found that only 1.9% of eligible patients received the vaccine.28 Physicians cite concerns about reimbursement as a barrier to its use.28