Herpes Zoster Treatment

Herpes zoster (shingles) presents as a painful vesicular rash and is caused by reactivation of the varicella-zoster virus within the dorsal root or cranial nerve ganglia.

Antiviral therapy

• first-line treatment and should be initiated within 72 hours of rash onset to increase the rate of healing and decrease pain.

• No study has investigated the effectiveness of later initiation of antiviral therapy, but it is believed to benefit patients with active vesicle eruptions.

• The benefit of antiviral therapy appears to be greatest in patients older than 50 years of age, in whom the pain of zoster generally persists longer.

 

REFERENCES	DOSING & FREQUENCY
MALAYSIAN NATIONAL ANTIBIOTIC GUIDELINES 2014	800mg PO 5 times daily for 7days
FRANK SHAN	> 12 years old : use adult dose ≥2 years old : 800mg 5 times a day for 7 days <2 years old : 400mg 5 times a day for 7 days
BNF FOR CHILDREN	1-23 months: 200mg 4times a day for 5 days 2-5 years: 400mg 4times a day for 5 days 6-11 years: 800mg 4times a day for 5 days 12-17 years: 800mg 5 times a day for 7 days
PAEDIATRIC FORMULARY	Treatment course usually 5-7 days in normal host. Duration of therapy in immunocompromised host usually 10 days or longer as clinically indicated. Months: 200mg 4times a day for 5 days 2-5 years: 400mg 4times a day for 5 days 6-11 years: 800mg 4times a day for 5 days 12-17 years: 800mg 5 times a day for 7 days
LEXICOMP	Children ≥ 12 years and Adolescents (off label use) : 800mg 5 times daily for 5 to 7 days (Red Book AAP 2012)

Corticosteroids

• The addition to acyclovir decreases the pain of acute herpes zoster and speeds lesion healing and return to daily activities.

• Combination therapy with corticosteroids and antivirals should be considered in older patients with no contraindications. 

• Although have anti-inflammatory effects that could be expected to decrease nerve damage and the risk of postherpetic neuralgia, a Cochrane review found no significant difference between corticosteroids and placebo in preventing postherpetic neuralgia six months after onset of the rash.

• associated with a considerable number of adverse effects and hence should be used only in patients with severe symptoms at presentation or in whom no major contraindications to corticosteroids exist, and only in combination with antiviral treatment.

  Treatment of Acute Zoster Asscociated Pain

• Mild to moderate pain may be controlled with acetaminophen or nonsteroidal anti-inflammatory drugs, alone or in combination with a weak opioid or tramadol.

• Moderate to severe pain requires scheduled opioids (e.g.,oxycodone, morphine). 

• The intensity of pain during the acute attack is an important predictor for the development of postherpetic neuralgia, and medications given during this phase may influence the outcome of later interventions for postherpetic neuralgia.

• If pain does not rapidly respond to opioid analgesics or if opioids are not tolerated, the prompt addition of an adjunctive therapy should be considered. Nortriptyline (Pamelor), gabapentin (Neurontin), and pregabalin (Lyrica) have been recommended, but they have not been
  extensively studied for pain relief in patients with acute herpes zoster.

 Adjuvant therapies 

• For patients with uncomplicated zoster, there is no role for adjuvant agents, such as gabapentin, tricyclic antidepressants, or glucocorticoids, in the acute setting. 

• There are no definitive data to suggest that tricyclic antidepressants in patients with herpes zoster prevent PHN from developing, and the risk of adverse events with tricyclic antidepressants is increased in elderly patients. 

• Although an early placebo-controlled trial of amitriptyline found that the risk of post-herpetic neuralgia was reduced by more than 50 percent among patients who received amitriptyline for 90 days, there were multiple limitations to this trial, and the additive benefit of tricyclics for pain reduction could not be adequately assessed.

References

1.http://iasp.files.cms-plus.com/Content/ContentFolders/Publications2/PainClinicalUpdates/Archives/pcu_vol23_no4_may2015.pdf

2. Fashner, J., & Bell, A. L. (2011). Herpes zoster and postherpetic neuralgia: prevention and management. Virus, 20, 99.

3. www.uptodate.com 

4. National ANtibiotic Guideline 2014