General Information

Periostat is a twice daily, orally administered tablet that has been approved as an adjunctive treatment to scaling and root planing (SRP), a deep cleaning of the teeth and gums. This drug promotes attachment level gain and reduces pocket depth in patients with adult periodontitis. The capsule formulation of Periostat was approved for use in September 1998.

Periodontitis is the most serious of the periodontal diseases, commonly referred to as gum diseases. It is remarkably common in adults over the age of 35, with some sources estimating that up to one third of American adults suffer from some form of periodontitis. The etiology of periodontitis is multifactorial. Its nature and severity are determined by complex interactions between infectious bacteria and a susceptible host. The end results of this interaction are the bone and soft tissue destruction and attachment loss that characterize periodontitis.

Current first-line therapies for periodontitis, such as SRP, primarily address the bacterial component of the disease. If indicated, SRP may be supplemented by antimicrobial drugs. Periostat is the first and only drug designed to reduce the activity of the enzymes that destroy tooth and gum tissue. When prescribed as an adjunct to SRP, it has been shown to help slow the progression of adult periodontitis more effectively than SRP alone.

Clinical Results

The efficacy of Periostat (doxycycline hyclate) as an adjunctive treatment for adult periodontitis was established in a randomized, multi-center, double-blind, nine month phase III study involving 190 subjects with periodontal disease. The effects of oral administration of twice daily Periostat tablets in combination with SRP procedures were compared to placebo plus SRP.

Results were based on measurements of pocket depth, attachment level, and bleeding-on-probing. Such measurements were obtained from the treated areas directly after SRP, after three months, six months, and nine months. Periostat administered with SRP improved clinical attachment level by up to 52 percent and reduced pocket depth by as much as 67 percent compared to SRP plus placebo. These benefits were observed as early as three months into the study and were maintained over the nine month period of the trial.

Mechanism of Action

Periostat (doxycycline hyclate) is an oral enzyme inhibitor that works by reducing the activity of host-derived enzymes, such as collagenase. Collagenase has been shown to be associated with the destruction of the periodontal support structures during the progression of adult periodontitis. Periostat is administered systemically, offering the additional advantage of being able to treat all the tooth sites simultaneously, a whole-mouth approach to the management of the host response.