Palabras clave: Acyclovir, varicella, Epistemonikos, GRADE.

Problem

Varicella is an infectious disease caused by the Varicella zoster virus. Most cases occur before the age of fourteen, determining school absenteeism and generating significant expenses.Traditionally, the management of this condition relies on symptomatic treatment only. However, 5 to 10% suffer skin, respiratory or central nervous system complications.
Acyclovir is an antiviral of virostatic action with a structure analogous to guanosine, which acts by inhibiting replication of Varicella zoster virus. However, its actual efficacy for the treatment of varicella remains unclear. 

Methods

To answer the question, we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others, to identify systematic reviews and their included primary studies. We extracted data from the identified reviews and reanalyzed data from primary studies included in those reviews. With this information, we generated a structured summary denominated FRISBEE (Friendly Summary of Body of Evidence using Epistemonikos) using a pre-established format, which includes key messages, a summary of the body of evidence (presented as an evidence matrix in Epistemonikos), meta-analysis of the total of studies when it is possible, a summary of findings table following the GRADE approach and a section of other considerations for decision-making. 

About the body of evidence for this question

* The information about primary studies is extracted from the systematic reviews identified, unless otherwise specified.

Summary of findings

The information on the effects of acyclovir is based on three randomized trials including 988 patients.
All trials reported time of appearance of new lesions, total number of lesions, and time until resolution of fever and skin complications (988 patients). Two trials [4],[5] also measured time to resolution of pruritus, and central nervous system and respiratory complications (826 patients).

The summary of findings is as follows:

• It is not clear if acyclovir decreases the days of appearance of new lesions, because the certainty of the evidence is very low.
• It is not clear if acyclovir decreases the total number of lesions because the certainty of the evidence is very low.
• Acyclovir probably decreases the duration of fever. The certainty of the evidence is moderate.
• It is not clear if acyclovir reduces the duration of itching because the certainty of the evidence is very low.
• Acyclovir might have minimal or no impact on varicella-associated skin complications, but the certainty of the evidence is low.
• Acyclovir might have minimal or no impact on central nervous system complications associated with varicella, but the certainty of the evidence is low.
• Acyclovir might have minimal or no impact on respiratory complications associated with varicella, but the certainty of the evidence is low.

Other considerations for decision-making

How we conducted this summary

Using automated and collaborative means, we compiled all the relevant evidence for the question of interest and we present it as a matrix of evidence.

Follow the link to access the interactive version: Acyclovir for varicella.

Notes

The upper portion of the matrix of evidence will display a warning of “new evidence” if new systematic reviews are published after the publication of this summary. Even though the project considers the periodical update of these summaries, users are invited to comment in Medwave or to contact the authors through email if they find new evidence and the summary should be updated earlier.

After creating an account in Epistemonikos, users will be able to save the matrixes and to receive automated notifications any time new evidence potentially relevant for the question appears.

This article is part of the Epistemonikos Evidence Synthesis project. It is elaborated with a pre-established methodology, following rigorous methodological standards and internal peer review process. Each of these articles corresponds to a summary, denominated FRISBEE (Friendly Summary of Body of Evidence using Epistemonikos), whose main objective is to synthesize the body of evidence for a specific question, with a friendly format to clinical professionals. Its main resources are based on the evidence matrix of Epistemonikos and analysis of results using GRADE methodology. Further details of the methods for developing this FRISBEE are described here (http://dx.doi.org/10.5867/medwave.2014.06.5997)

Epistemonikos foundation is a non-for-profit organization aiming to bring information closer to health decision-makers with technology. Its main development is Epistemonikos database (www.epistemonikos.org).

Potential conflicts of interest

The authors do not have relevant interests to declare.

Esta obra de Medwave está bajo una licencia Creative Commons Atribución-NoComercial 3.0 Unported. Esta licencia permite el uso, distribución y reproducción del artículo en cualquier medio, siempre y cuando se otorgue el crédito correspondiente al autor del artículo y al medio en que se publica, en este caso, Medwave.