Early acyclovir reduces the duration of acute therapy zoster infection
Date First Published:
March 1, 2000
Last Updated:
April 17, 2001
Report by:
Polly Terry, SpR in Emergency Medicine (Manchester Royal Infirmary)
Search checked by:
Susan Buttress, Manchester Royal Infirmary
Three-Part Question:
In [immunocompetent adults with acute shingles] is [early acyclovir better than late acyclovir] at [promoting rash healing and minimising the painful period]?
Clinical Scenario:
A 56 year old immunocompetent man presents to the emergency department at 10pm on a Saturday night with acute shingles. You know acyclovir is effective but wonder how quickly it needs to be started.
Search Strategy:
Medline 1966-05/00 using the OVID interface.
Search Details:
({exp herpes zoster OR herpes zoster.mp OR shingles} AND {exp acyclovir OR acyclovir.mp OR exp antiviral agents OR antiviral agent$.mp OR anti viral.mp OR anti-viral.mp}) AND maximally sensitive RCT filter LIMIT to human AND english.
Outcome:
23 papers found of which 20 were irrelevant or of insufficient quality for inclusion, or subject to metaanalysis. The remaining 3 papers are shown in the table.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| The effect of treating herpes zoster with oral acyclovir in preventing postherpetic neuralgia Jackson JL, Gibbons R, Meyer G et al. 1997, USA | 5 placebo controlled randomised clinical trials. All trials used acyclovir 800mg 5 times daily within 72 h of onset | Metaanalysis | Pain at 6 months | Summary odds ratio 0.54 (0.36-0.81) in patients treated with acyclovir | |
| The identification of risk factors associated with persistent pain following herpes zoster Whitley RJ, Shukla S, Crooks RJ. 1998 USA | 6 randomised controlled double blind studies. Trials 1 to 3 compared oral acyclovir with placebo | Metaanalysis | Factors influencing duration of pain | Age, prodromal pain, acute pain intensity | No separate data for trials 1-3. |
| Factors not influencing duration of pain | Sex, time from rash onset to initiation of treatment | ||||
| treatment of acute herpes zoster: Effect of early (< 48 h) versus late (48-72 h) therapy with acyclovir and valaciclovir on prolonged pain Wood MJ, Shukla S, Fiddian AP et al. 1998, UK | 3 placebo-controlled studies or oral acyclovir. All trials used acyclovir 800mg 5 times daily.. Early (< 48 h) vs late (48 - 72h) treatment | Metaanalysis | Resolution of zoster-related pain in: | Hazard ratio 1.79 (1.43-2.39) | |
| All patients | Hazard ratio 2.13 (1.42-3.19) | ||||
| Patients over 50 y |
Author Commentary:
All 3 metaanalyses used 3 core papers - but there was enormous variation in the other papers otherwise. Thus selection bias may have occurred.
Bottom Line:
Early oral acyclovir (less than 48 hours after onset of rash) will significantly shorten the duration of herpes related pain in shingles.
References:
- Jackson JL, Gibbons R, Meyer G et al.. The effect of treating herpes zoster with oral acyclovir in preventing postherpetic neuralgia
- Whitley RJ, Shukla S, Crooks RJ.. The identification of risk factors associated with persistent pain following herpes zoster
- Wood MJ, Shukla S, Fiddian AP et al.. treatment of acute herpes zoster: Effect of early (< 48 h) versus late (48-72 h) therapy with acyclovir and valaciclovir on prolonged pain