“This particular herpes virus attacks the heart of a young elephant,” Hinshaw said. Here, we present for the first time a comprehensive overview of antiviral drugs approved over the past 50 years, shedding light on the development of effective antiviral treatments against current and emerging infectious diseases worldwide. We found four RCTs, three of which examined the effects of 5% aciclovir cream. The other trial examined the effects of a non-proprietary agent, and we were unable to draw robust conclusions from this RCT. “This is a relatively common experience in the animal world – one in which one species can carry a virus with no ill effect [to itself], but if it’s transmitted to another species, it can cause death. The review only included studies of 5% aciclovir cream. All participants had recurrent herpes labialis, two RCTs included people with sun-triggered lesions, and one RCT included HSV seropositive subjects.
The RCTs were published between 1986 and 1991. The review pooled data and reported on three outcomes: recurrence of lesions during the antiviral treatment (lesion outbreak); participant satisfaction; and adverse effects. For other outcomes reported in this BMJ Clinical Evidence overview, such as time to healing and symptom improvement, we have reported RCTs directly from their original reports. We also found one subsequent RCT, which compared a non-proprietary gel versus placebo (see Further information on studies). Topical antivirals compared with placebo We don’t know whether prophylactic 5% aciclovir cream is more effective than placebo cream at reducing the outbreak of lesions in people with recurrent herpes labialis. A non-proprietary topical gel (containing 2-hydroxypropyl-ß-cyclodextrin) may be less effective than placebo at reducing relapses in people with recurrent herpes labialis, but evidence was weak (). Topical antivirals compared with placebo We don’t know whether prophylactic 5% aciclovir cream is more effective than placebo cream at reducing the duration of pain in people with herpes labialis precipitated by exposure to sunlight.
We don’t know whether a non-proprietary topical gel (containing 2-hydroxypropyl-beta-cyclodextrin) is more effective than placebo at reducing symptoms, as we found insufficient evidence from one RCT (). Topical antivirals compared with placebo We don’t know whether prophylactic aciclovir cream is more effective than placebo cream at reducing mean healing time in people with herpes labialis precipitated by exposure to sunlight (). Methods Of the three included RCTs, all had unclear risk of bias for adequate sequence generation, two had unclear risk of bias for allocation concealment, and two had unclear risk for incomplete outcome data. One RCT was at high risk for incomplete outcome data, and one RCT was reported to be at high risk of bias overall. One RCT used artificial (experimental) ultraviolet light as a trigger. All used 5% aciclovir cream, one RCT over 32 weeks, one RCT 12 hours before sun exposure to a maximum of 7 days, and one RCT for 7 days prior to artificial ultraviolet light exposure. The review also performed an analysis for all antiviral agents (topical and oral) versus placebo (see Prophylactic oral antiviral agents versus placebo or no treatment).
This double-blind RCT (40 immunocompetent adults, 18–50 years, at least 8 herpes labialis relapses in the previous year) compared a topical gel (composed of 20% 2-hydroxypropyl-beta-cyclodextrin [2-HPBCD] dissolved in various polyethylene glycols [PEGs]) with placebo (a mixture of the same PEGs) applied to lips twice daily for 6 months. The study did not report methods of allocation concealment, randomisation, or blinding. The study drug was provided by the pharmaceutical company that sponsored the study. The RCT reported that both groups had significantly fewer recurrences during study treatment compared to the time before the study (baseline analysis), which led it to suggest the possibility that the PEG component in both groups may have had some effect. However, this was speculative, and this RCT was not designed to test this hypothesis.