Pharmacology Update

Acyclovir Buccal Tablets (Sitavig)

By William T. Elliott, MD, FACP, and James Chan, PharmD, PhD, Dr. Elliott is Chair, Formulary Committee, Northern California Kaiser Permanente; and Assistant Professor of Medicine, University of California, San Francisco. Dr. Chan is Pharmacy Quality and Outcomes Manager, Kaiser Permanente, Oakland, CA. Drs. Elliott and Chan report no financial relationships relevant to this field of study.

The FDA has approved a buccal formulation of Acyclovir for the treatment of recurrent cold scores. The product uses a mucoadhesive technology that delivers the drug in high concentration to the site of the cold sore. Acyclovir buccal tablets are manufactured by Farmea in France and marketed as Sitavig by BioAlliance Pharma.

Indications

Acyclovir buccal is indicated for the treatment of recurrent herpes labialis (cold scores) in immunocompetent adults.1

Dosage

The recommended dose is one tablet applied to the upper gum (above the incisor tooth) within 1 hour after the onset of prodromal symptoms and before the occurrence of any signs of herpes labialis.1 It should be applied on the same side of the mouth as the herpes symptoms. The tablet is allowed to dissolve during the day or for at least 6 hours. Acyclovir buccal tablets are available as 50 mg tablets.

Potential Advantages

Acyclovir buccal provides high salivary concentrations of acyclovir. After a single application, the maximum mean salivary concentration is 440 mcg/mL 8 hours after application.1

Potential Disadvantages

Milk protein is an inactive ingredient of acyclovir buccal tablets and the product is contraindicated in individuals who have a known hypersensitivity to milk protein.1

Comments

The safety and efficacy of acyclovir buccal was studied in a randomized, double-blind, placebo-controlled study.1 Subjects had recurrent herpes labialis of at least four episodes in the previous year. Approximately 70% had five or more episodes. Subjects were randomized to acyclovir buccal 50 mg (n = 378) or placebo (n = 397). The efficacy endpoint was the duration of the recurrent herpes episode. Analysis was based on intent-to-treat. Acyclovir application resulted in an approximate half-day shorter duration of the episode. Buccal acyclovir is well tolerated with gingival pain, application site pain and irritation, and aphthous stomatitis, occurring in about 1% of subjects.1 There are currently no published trials with other treatment regimens.

Clinical Implications

Recurrent herpes simplex labialis is a common condition affecting up to 40% of the U.S. population. It is generally self-limiting with healing occurring in 7-10 days. The window to affect the disease course is small as treatment needs to be initiated early after the onset of prodromal symptoms. Current pharmacotherapy includes valacyclovir (2 g twice daily for 1 day), oral acyclovir (400 mg 5 times a day for 5 days), topical penciclovir (apply every 2 hours for 4 days during waking hours), topical acyclovir (applied 5 times a day for 4 days), and docosanol (10% applied 5 times daily). These regimens shorten healing time by one-half to 1.3 days.2 Oral treatment tends to be more effective. The single dose of buccal acyclovir reduces healing by one-half a day. It offers a new option for a common recurrent condition. As for prophylactic management, systemic antiviral therapy appeared to have modest benefit in preventing recurrent herpes labialis.3 The cost for buccal acyclovir was not available at the time of this review.

References

1. Sitavig Prescribing Information. Paris, France: BioAlliance Pharma; April 2013.

2. Chon T, et al. Clinical inquiries. What are the best treatments for herpes labialis? J Fam Pract 2007;56: 576-578.

3. Rahimi H, et al. Effectiveness of antiviral agents for the prevention of recurrent herpes labialis: A systematic review and meta-analysis. Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:618-627.