Use of acyclovir in chickenpox
| Citation, country | Study group | Study type (level of evidence) | Outcome | Key results | Comments |
|---|---|---|---|---|---|
| Klassen et al4 | 988 children aged between 2 and 18 years as per three studies in table below | Cochrane Systematic Review (level 1a) | Number of days to no new lesions, number of days to no fever, maximum number of lesions, days to relief of itching, complication rate | 2 of 3 studies showed statistically significant reduction in days to no new lesions, days to relief of itching and reduction of maximum number of lesions. Days to no fever reduced in all studies. Numerous adverse reactions noted in both groups but no significant difference between groups regarding complications arising from varicella | Meta-analysis not done due to small number of studies and their different study populations |
| Balfour et al, USA1 | 105 children, mean age 8.05 years with laboratory confirmed varicella. Randomised to age and weight related dose of acyclovir v placebo | Randomised, placebo controlled double blind trial (level 1b) | Time to reduction of fever and cessation of itching, number of skin lesions, time to cutaneous healing, | Acyclovir group: defervesced sooner (median 1 day v 2 days; p = 0.001), experienced onset of cutaneous healing sooner (median, 2 days v 3 days; p = 0.002), and had fewer skin lesions (median, 500 v 336; p = 0.02), no change in complication rate (10% v 13.5%) | Quality score (Jadad scale) = 4 Pharmaceutical sponsorship, inadequate discussion of withdrawn patients |
| Dunkle et al, USA2 | 815 children, mean age 5.18 years with clinically diagnosed varicella. Randomised to weight related dose of acyclovir v placebo | Multicentre, double blind placebo controlled trial (level 1b) | Maximum of lesions, number with >500 lesions, residual lesions at 28 days | Acyclovir group: had fewer lesions (mean 294 v 347; p<0.001), smaller proportion had >500 lesions (21% v 38%; p<0.001), accelerated progression to crusting and healing plus fewer residual lesions at 28 days. No significant difference in disease complications | Quality score (Jadad scale) = 3 Pharmaceutical sponsorship, poorly described methods of randomisation and double blinding |
| Balfour et al, USA3 | 68 children, mean age 14.8 years with laboratory confirmed varicella. Randomised to acyclovir 800 mg QDS or placebo | Randomised, placebo controlled double blind trial (level 1b) | Days to max number of lesions and cessation of itching, maximum number of lesions, residual lesions at 28 days | Acyclovir group had reduction in: time to cessation of new lesions (p<0.001), maximum number of lesions (p = 0.019), time to defervescence (p = 0.045), number of lesions at 28 days (mean 22.7 v 92.7), constitutional illness score (mean 0.5 v 1.5, p = 0.05) | Quality score (Jadad scale) = 3 Pharmaceutical sponsorship, poorly described methods of randomisation and double blinding |