CURATEK’s METROGEL-VAGINAL APPROVED AUG. 17 FOR BACTERIAL VAGINOSIS

CURATEK's METROGEL-VAGINAL APPROVED AUG. 17 FOR BACTERIAL VAGINOSIS and is expected to be shipped "within the next several weeks," Elk Grove Village, Ill.-based Curatek said Aug 27. MetroGel-Vaginal (metronidazole .75% gel) is the second approved prescription product for bacterial vaginosis. Upjohn's Cleocin (clindamycin phosphate 2% vaginal cream) was approved by FDA on Aug. 11 ("The Pink Sheet" Aug. 17, T&G-4). Curatek filed the MetroGel-Vaginal NDA in December 1991. The product is the first metronidazole intravaginal formulation. Oral metronidazole for bacterial vaginosis can produce side effects such as nausea and vomiting. Curatek received an NDA approval for MetroGel (metronidazole 7.5%) as a topical antibacterial/antiprotozoal in November 1988. Curatek is stressing the "targeted action" of metronidazole against anaerobic bacteria that cause bacterial vaginosis. MetroGel "does not destroy the lactobacilli that protect against the overgrowth of yeast and other pathogenic bacteria," the firm noted. The general precautions section of approved labeling states that "approximately 6% of patients treated with MetroGel-Vaginal developed symptomatic Candida vaginitis during or immediately after therapy." In comparison, the labeling for Cleocin, a broad spectrum antibiotic, notes that approximately "16% of patients treated with [Cleocin] developed symptomatic cervicitis/vaginitis with 11% of patients developing cervicitis/vaginitis secondary to Candida Albicans." Labeling for MetroGel-Vaginal cautions that vaginal candidiasis may show "more prominent symptoms" during use of the product. Cleocin labeling states that use of the cream "may result in the overgrowth of nonsusceptible organisms -- particularly yeasts -- in the vagina." In the approval letters for both MetroGel-Vaginal and Cleocin, FDA cautions against making claims of superior effectiveness when compared to other bacterial vaginosis products. Both firms demonstrated their products were comparable, but not superior to, triple sulfonamide cream in clinical effectiveness trials, FDA noted. Ortho markets triple sulfonamide cream under the brand name Sultrin. FDA also cautioned Curatek against making favorable comparative claims regarding its pH 4.0 formulation. The agency recommended against "any reference or implication that the buffering capacity of your formulation of metronidazole vaginal gel, .75% results in either a positive clinical effect or an actual or potential superiority over other vaginal formulations." The labeling includes precautions against reactions seen in the oral dosage form of metronidazole. Labeling states that MetroGel-Vaginal "affords minimal peak serum levels and systemic exposure...of metronidazole compared to 500 mg oral metronidazole dosing. Although these lower levels of exposure are less likely to produce the common reactions seen with oral metronidazole, the possibility of these and other reactions cannot be excluded presently." Because of reactions associated with oral dosing, "the appearance of abnormal neurologic signs demands the prompt discontinuation of metronidazole vaginal gel therapy," the labeling warns. Information to the patient includes a warning not to drink alcohol while being treated with MetroGel-Vaginal due to reactions seen in the oral dosage form. The recommended dosage regimen for MetroGel-Vaginal is 5 grams morning and evening for five days. The product, formulated as a water-based gel, is supplied in a 70 gram tube with a reusable applicator.