General Information

Sitavig (acyclovir) is an antiviral buccal tablet formulated on the company's proprietary Lauriad muco-adhesive technology. Acyclovir is a synthetic purine nucleoside analogue active against herpes viruses.

Sitavig is specifically indicated for the treatment of recurrent herpes labialis in immunocompetent adults.

Mechanism of Action

Sitavig (acyclovir) is an antiviral buccal tablet formulated on the company's proprietary Lauriad muco-adhesive technology. Acyclovir is a synthetic purine nucleoside analogue active against herpes viruses. Following conversion into a triphosphate, acyclovir triphosphate inhibits replication of herpes viral DNA by competing with nucleotides for binding to the viral DNA polymerase and by incorporation into and termination of the growing viral DNA chain. The cellular thymidine kinase of normal, uninfected cells does not use acyclovir effectively as a substrate, hence toxicity to mammalian host cells is low.

Side Effects

Adverse events associated with the use of Sitavig may include, but are not limited to, the following:

• headache
• application site pain

Dosing/Administration

Sitavig is supplied as a tablet for oral administration. One Sitavig 50 mg buccal tablet should be applied as a single dose to the upper gum region and held in place with a slight pressure over the upper lip for 30 seconds to ensure adhesion. The tablet should be applied within one hour after the onset of symptoms and before the appearance of any signs of herpes labialis lesions.

Clinical Trial Results

The FDA approval of Sitavig was based on a randomized, double-blind, placebo-controlled, patient-initiated, multicenter trial in adults with recurrent herpes labialis (cold sores). A total of 771 subjects were included in the intent-to-treat analysis; the subjects received Sitavig 50 mg administered as a single dose or placebo. The subjects were instructed to initiate treatment within one hour after the onset of prodromal symptoms and before the appearance of any signs of herpes labialis lesions by applying the tablet to the buccal mucosa. The mean and median durations of the recurrent herpes labialis episode were approximately half a day shorter in subjects treated with Sitavig compared with subjects treated with placebo