section name header

Evidence summaries

Oral Antiviral Agents for Prevention of Herpes Simplex Labialis

Long-term (> 1 month) use of oral antiviral agents appears to prevent herpes simplex labialis (HSL), but the clinical benefit is small. Level of evidence: "B"

The quality of evidence is downgraded by study limitations (lack of/unclear allocation concealment).

Summary

A Cochrane review [Abstract] 1 included 32 studies with a total of 2640 immunocompetent subjects covering 19 treatments. Only studies on oral antiviral agents are referred here.

The evidence for short-term (≤ 1 month) use of oral aciclovir in preventing recurrent HSL was inconsistent across the doses used in the studies: 2 RCTs showed reduced recurrence of HSL with aciclovir 400 mg twice daily (RR 0.26, 95% CI 0.13 to 0.51; n = 177), while 1 RCT testing aciclovir 800 mg twice daily and 2 RCTs testing 200 mg 5 times daily found no similar preventive effects (RR 1.08, 95% CI 0.62 to 1.87; n = 237; and RR 0.46, 95% CI 0.20 to 1.07; n = 66). The direction of intervention effect was unrelated to the risk of bias. The evidence from 1 RCT for the effect of short-term use of valaciclovir in reducing recurrence of HSL by clinical evaluation was uncertain (RR 0.55, 95% CI 0.23 to 1.28; n = 125), as was the evidence from 1 RCT testing short-term use of famciclovir.

Long-term (> 1 month) use of oral antiviral agents reduced the recurrence of HSL. There was evidence from 1 RCT that long-term use of oral aciclovir reduced clinical recurrences (1.80 versus 0.85 episodes per participant per a 4-month period, P = 0.009) and virological recurrence (1.40 versus 0.40 episodes per participant per a 4-month period, P = 0.003). One RCT found long-term use of valaciclovir effective in reducing the incidence of HSL (with a decrease of 0.09 episodes per participant per month; n = 95). One RCT found that a long-term suppressive regimen of valaciclovir had a lower incidence of HSL than an episodic regimen of valciclovir (difference in means (MD) -0.10 episodes per participant per month, 95% CI -0.16 to -0.05; n = 120).

These trials found no increase in adverse events associated with the use of oral antiviral agents (moderate quality evidence).

There was no evidence to show that short-term use of topical antiviral agents prevented recurrent HSL.

Clinical comments

Note

Date of latest search: 2015-05-19

    References

    • Chi CC, Wang SH, Delamere FM et al. Interventions for prevention of herpes simplex labialis (cold sores on the lips). Cochrane Database Syst Rev 2015;8():CD010095. [PubMed]

Primary/Secondary Keywords