News: Making sense of herpes Tx

September 1, 2008

While diagnosing genital and labial herpes simplex virus (HSV) infections isusualy straightforward, treatment is anything but.

While diagnosing genital and labial herpes simplex virus (HSV) infections is usually straightforward, treatment is anything but, because dosing of the three available antiviral drugs-acyclovir, valacyclovir hydrochloride, and famciclovir-differs depending on the exact indication.

For example, intermittent episodic dosing for initial primary labial infections consists of either oral acyclovir suspension, 15 mg/kg five times a day for 1 week; valacyclovir HCL, 1 g bid for 7 days; or famciclovir, 500 mg bid or once a day for 7 days. Incidentally, the Food and Drug Administration has approved none of these dosing schedules for this indication.

Intermittent episodic treatment of recurrent labial herpes infections consists of either acyclovir, 400 mg five times a day (fid) for 5 days (not approved by the FDA); valacyclovir HCL, 2 g bid for 1 day; or famciclovir, three 500-mg tablets as a single dose. While topical treatments do not appear to be as effective as systemic ones, options include penciclovir cream 1% applied q 2 hours during waking hours for 4 days and acyclovir cream 5% applied fid for 4 days.

The dosing options for intermittent episodic therapy for recurrent genital herpes infections are numerous. The most evidence surrounds acyclovir, either 400 mg tid for 5 days or 5 to 10 days, but neither schedule is approved by the FDA for this purpose, despite being recommended by the CDC. The CDC discourages use of topical formulations for this purpose, stating they provide minimal benefit.

None of the dosing schedules for chronic suppressive therapy of labial infections are approved by the FDA, but choices include acyclovir, 400 mg bid; valacyclovir HCL, 500 mg or 1 g once daily or 500 mg bid; or famciclovir, 500 mg bid.

And finally the options for chronic suppressive therapy of genital herpes infections include acyclovir, 400 mg bid or 400 to 800 mg bid to tid (400 to 800 mg bid to tid is not approved by the FDA, but is recommended by the CDC); valacyclovir HCL, 500 mg or 1 g daily or 250 mg (250 mg bid is not approved by the FDA, but recommended by the CDC) or 500 mg bid; or famciclovir, 250 mg or 500 mg bid (500 mg bid is not approved by the FDA, but is recommended by the CDC).

Cernik C, Gallina K, Brodell RT. The treatment of herpes simplex infections: an evidence-based review. Arch Intern Med.2008;168:1137-1144.