Treatment for Postherpetic Neuralgia
Postherpetic neuralgia (PHN) is difficult to treat. Once PHN develops, a patient may need a multidisciplinary approach that involves a pain specialist, primary care physician, and other health care providers.
The American Academy of Neurology (AAN) treatment guidelines for postherpetic neuralgia recommend:
- Tricyclic antidepressants (amitriptyline, nortriptyline, desipramine, maprotiline)
- Anticonvulsants (gabapentin and pregabalin)
- Lidocaine skin patches
- Opioids (oxycodone, methadone, morphine)
Topical Treatments for Postherpetic Neuralgia
Creams, patches, or gels containing various substances can provide some pain relief.
- Lidocaine. A patch that contains the anesthetic lidocaine (Lidoderm, generic) is approved specifically for postherpetic neuralgia (PHN). One to four patches can be applied over the course of 24 hours. Another patch (EMLA) contains both lidocaine and prilocaine, a second anesthetic. The most common side effects are skin redness or rash.
- Capsaicin. Capsaicin is a chemical compound found (in hot chili peppers. A prescription capsaicin skin patch (Qutenza) is approved for pain relief of PHN. The patch must be applied by a healthcare professional as placement of the patch can be painful. Because the patch may increase blood pressure, the patient should be monitored for at least 1 hour after the patch is applied. A lower-concentration ointment form of capsaicin (Zostrix) is available over the counter, but its benefits may be limited.
- Topical Aspirin. Topical aspirin, known chemically as triethanolamine salicylate (Aspercreme, generic), may bring relief.
- Menthol-Containing Preparations. Topical gels containing menthol, such as high-strength Flexall 454, may be helpful.
Tricyclic antidepressants may help relieve PHN pain. Nortriptyline (Pamelor, generic), amitriptyline (Elavil, generic), and desipramine (Norpramin, generic) are the standard drugs used for treating PHN.
It may take several weeks for the drugs to become fully effective. They do not work as well in patients who have burning pain or allodynia (pain that occurs with normally non-painful stimulus, such as a light touch or wind).
Unfortunately, tricyclics have side effects that are particularly severe in the elderly, who are also more likely to have PHN. Desipramine and nortriptyline have fewer side effects than amitriptyline and are preferred for older patients. Side effects include dry mouth, blurred vision, constipation, dizziness, difficulty urinating, disturbances in heart rhythms, and an abrupt drop in blood pressure when standing up.
Anticonvulsant (Anti-Seizure) Drugs
Certain anticonvulsant drugs have effects that may be helpful for PHN. (Anticonvulsant drugs are also known as anti-seizure drugs.) Gabapentin (Neurontin, generic) and pregabalin (Lyrica) are approved for treatment of PHN. Side effects may include dizziness, sleepiness, blurry vision, weight gain, trouble concentrating, and swelling of hands and feet. Anticonvulsant medications can increase the risk of suicidal thoughts and behavior.
Opioids and Opioid-like Drugs
Opioids. Patients with severe pain that does not respond to tricyclic antidepressants or anticonvulsants may need powerful painkilling opioid drugs. The use of narcotics is controversial as these drugs can be addictive. These drugs may be taken by mouth or delivered through a skin patch. Oxycodone is the standard opioid for PHN. It is available in different formulations (Percocet, Percodan, Oxycontin, generic.) Morphine may also used. Constipation, drowsiness, and dry mouth are common side effects of opioids.
Tramadol. Tramadol (Ultram, generic) is a pain reliever that is used as an alternative to opioids. It has opioid-like properties but is not as addictive. (Dependence and abuse have been reported, however.) Side effects are similar to opoids.
Pain Management Techniques
A number of relaxation and stress-reduction techniques may be helpful for managing chronic pain. They include meditation, deep breathing exercises, biofeedback, self-hypnosis, and muscle relaxation. Psychotherapy approaches such as cognitive behavioral therapy may help patients learn how to cope with and manage their responses to pain. [For more information, see In-Depth Report #31: Stress.]
Certain surgical techniques in the brain or spinal cord attempt to block nerve centers associated with postherpetic neuralgia. These methods carry risk for permanent damage, however, and should be used only as a last resort when all other methods have failed and the pain is intolerable. Most studies indicate that surgery does not relieve PHN pain.