Pain control for short- and long-term benefit
The rationale for augmenting antiviral therapy is that enhanced relief of acute pain may reduce the risk of PHN still further. Evidence for the efficacy of corticosteroids, conventional analgesics, and certain antidepressants and anti-epileptic drugs in this regard is limited. But as the authors point out, “Effective acute pain relief is [in itself] a very desirable treatment goal.”
Pain severity determines whether and which drugs to add to antiviral treatment. Oral corticosteroids may be considered “as soon as possible after diagnosis” when pain is moderately severe (and there are no contraindications), the authors say.
Acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), alone or combined with codeine or another weak opioid analgesic, are indicated for relief of mild-to-moderate pain. Prescribe them to maintain constant analgesia rather than as needed for exacerbations, the Recommendations advise. Stronger opioid analgesics (e.g., oxycodone or morphine) may be indicated for more severe pain; long-acting preparations have advantages for HZ patients.
Other approaches are generally best reserved for instances when standard analgesics have been inadequate, the authors state. The anti-epileptic drugs gabapentin and pregabalin are approved for PHN, and they are safer and more tolerable than other drugs prescribed for neuropathic pain. While the data on efficacy in HZ per se are limited, the Recommendations suggest that adding gabapentin to an antiviral alleviates acute pain and reduces the risk of PHN. High doses (e.g., 3,600 mg gabapentin, 600 mg pregabalin) may be necessary.
Tricyclic antidepressants have established benefits for PHN, and one placebo-controlled trial found that adding amitriptyline to antiviral therapy for acute HZ reduced PHN incidence by half. Tolerability and safety concerns limit this agent’s utility, however, particularly for the elderly. Nortriptyline is preferable.
Pain that remains substantial despite antiviral and adjunctive medication should be referred to a pain specialist or a pain center for evaluation and possible neural blockade.
Nondrug management is important too
Patient education and support are important in HZ management. These include explanations of the disease, the treatment plan, and the necessity of scrupulous adherence to the antiviral regimen. Any misconceptions and fears about HZ raised by the patient should be addressed, and patients should be cautioned about the risk of infecting individuals who have not had chickenpox. Counsel patients to keep the rash clean and dry to minimize the risk of bacterial superinfection, to report any increase in temperature, and to use sterile wet dressings to reduce discomfort.
Topical antibiotics and adhesive dressings can delay rash healing and should be avoided. There appears to be no role for topical antiviral or corticosteroid preparations.
When you encounter special cases
Immunocompromise resulting from disease (e.g., HIV, malignancy) or medical intervention (e.g., organ transplantation, corticosteroid therapy) increases the risk of HZ and of dissemination and visceral involvement. IV acyclovir is the treatment of choice when immunocompromise is severe. Outpatient oral antiviral treatment has obvious advantages in less extreme cases, and data, though limited, support its safety and efficacy.
Elderly individuals in poor health or with diminished functional status are also vulnerable to viral dissemination, and the pain of HZ may initiate a spiral of inactivity, poor nutrition, cognitive impairment, and loss of independence. Dosages of adjunctive medications may need to be adjusted in light of physiologic changes and nonpharmacologic interventions initiated to maintain nutrition and assist activities of daily living.
Failure of the rash to heal, neurologic or ophthalmologic complications, or symptoms suggesting dissemination usually merit referral to an appropriate specialist.
Recommendations for the Management of Herpes Zoster was published in Clinical Infectious Diseases (2007;44 [Suppl 1]:S1-S26) and is available online at www.journals.uchicago.edu/doi/pdf/10.1086/510206 (accessed August 6, 2008).
Mr. Sherman is a medical writer in New York City.