Duac Information
Duac (Clindamycin)
Duac (Clindamycin) Description
Duac (Clindamycin) Topical Gel contains clindamycin phosphate, (7(S)-chloro-7-deoxylincomycin-2-phosphate), equivalent to 1% clindamycin, and 5% benzoyl peroxide.
Clindamycin phosphate is a water soluble ester of the semi-synthetic antibiotic produced by a 7(S)-chloro-substitution of the 7(R)-hydroxyl group of the parent antibiotic lincomycin.
Clindamycin phosphate is CHClNOPS. The structural formula for clindamycin phosphate is represented below:
Clindamycin phosphate has a molecular weight of 504.97 and its chemical name is methyl 7-chloro-6,7,8-trideoxy-6-(1-methyl--4-propyl-L-2-pyrrolidinecarboxamido)-1-thio-L--α-D--octopyranoside 2-(dihydrogen phosphate).
Benzoyl peroxide is CHO. It has the following structural formula:
Benzoyl peroxide has a molecular weight of 242.23.
Each gram of Duac (Clindamycin) Topical Gel contains 10 mg (1%) clindamycin, as phosphate, and 50 mg (5%) benzoyl peroxide in a base consisting of carbomer homopolymer (type C), dimethicone, disodium lauryl sulfosuccinate, edetate disodium, glycerin, methylparaben, poloxamer 182, purified water, silicon dioxide, and sodium hydroxide.
Duac (Clindamycin) Clinical Pharmacology
A comparative study of the pharmacokinetics of Duac (Clindamycin) Topical Gel and 1% clindamycin solution alone in 78 patients indicated that mean plasma clindamycin levels during the four week dosing period were
Benzoyl peroxide has been shown to be absorbed by the skin where it is converted to benzoic acid. Less than 2% of the dose enters systemic circulation as benzoic acid.
Duac (Clindamycin) Clinical Studies
In five randomized, double-blind clinical studies of 1,319 patients, 397 used Duac (Clindamycin) Topical Gel, 396 used benzoyl peroxide, 349 used clindamycin and 177 used vehicle. Duac (Clindamycin) Topical Gel applied once daily for 11 weeks was significantly more effective than vehicle, benzoyl peroxide, and clindamycin in the treatment of inflammatory lesions of moderate to moderately severe facial acne vulgaris in three of the five studies (Studies 1, 2, and 5).
Patients were evaluated and acne lesions counted at each clinical visit: weeks 2, 5, 8, 11. The primary efficacy measures were the lesion counts and the investigator’s global assessment evaluated at week 11. Patients were instructed to wash the face, wait 10 to 20 minutes, and then apply medication to the entire face, once daily, in the evening before retiring. Percent reductions in inflammatory lesion counts after treatment for 11 weeks in these five studies are shown in the following table:
The Duac (Clindamycin) Topical Gel group showed greater overall improvement in the investigator’s global assessment than the benzoyl peroxide, clindamycin and vehicle groups in three of the five studies (Studies 1, 2, and 5).
Clinical studies have not adequately demonstrated the effectiveness of Duac (Clindamycin) Topical Gel versus benzoyl peroxide alone in the treatment of non-inflammatory lesions of acne.
Duac (Clindamycin) Indications And Usage
Duac (Clindamycin) Topical Gel is indicated for the topical treatment of inflammatory acne vulgaris.
Duac (Clindamycin) Topical Gel has not been demonstrated to have any additional benefit when compared to benzoyl peroxide alone in the same vehicle when used for the treatment of non-inflammatory acne.
Duac (Clindamycin) Contraindications
Duac (Clindamycin) Topical Gel is contraindicated in those individuals who have shown hypersensitivity to any of its components or to lincomycin. It is also contraindicated in those having a history of regional enteritis, ulcerative colitis, pseudomembranous colitis, or antibiotic-associated colitis.
Duac (Clindamycin) Warnings
Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation and treatment with an antibacterial drug clinically effective against colitis.
Duac (Clindamycin) Precautions
For dermatological use only; not for ophthalmic use. Concomitant topical acne therapy should be used with caution because a possible cumulative irritancy effect may occur, especially with the use of peeling, desquamating, or abrasive agents.
The use of antibiotic agents may be associated with the overgrowth of nonsusceptible organisms, including fungi. If this occurs, discontinue use of this medication and take appropriate measures.
Avoid contact with eyes and mucous membranes.
Clindamycin and erythromycin containing products should not be used in combination. studies have shown antagonism between these two antimicrobials. The clinical significance of this antagonism is not known.
Benzoyl peroxide has been shown to be a tumor promoter and progression agent in a number of animal studies. Benzoyl peroxide in acetone at doses of 5 and 10 mg administered twice per week induced squamous cell skin tumors in transgenic TgAC mice in a study using 20 weeks of topical treatment. The clinical significance of this is unknown.
In a 2-year dermal cercinogenicity study in mice, treatment with Duac (Clindamycin) Topical Gel at doses up to 8000 mg/kg/day (16 times the highest recommended adult human dose of 2.5 g Duac (Clindamycin) Topical Gel, based on mg/m) did not cause an increase in skin tumors. However, topical treatment with another formulation containing 1% clindamycin and 5% benzoyl peroxide at doses of 100, 500, or 2000 mg/kg/day caused a dose-dependent increase in the incidence of keratoacanthoma at the treated skin site of male rats in a 2-year dermal carinogenicity study in rats.
In a 52-week photocarcinogenicity study in hairless mice (40 weeks of treatment followed by 12 weeks of observation), the median time to onset of skin tumor formation decreased and the number of tumors per mouse increased relative to controls following chronic concurrent topical treatment with Duac (Clindamycin) Topical Gel and exposure to ultraviolet radiation.
Genotoxicity studies were not conducted with Duac (Clindamycin) Topical Gel. Clindamycin phosphate was not genotoxic in or in a rat micronucleus test. Benzoyl peroxide has been found to cause DNA strand breaks in a variety of mammalian cell types, to be mutagenic in tests by some but not all investigators, and to cause sister chromatid exchanges in Chinese hamster ovary cells.
Studies have not been performed with Duac (Clindamycin) Topical Gel or benzoyl peroxide to evaluate the effect on fertility. Fertility studies in rats treated orally with up to 300 mg/kg/day of clindamycin (approximately 120 times the amount of clindamycin in the highest recommended adult human dose of 2.5 g Duac (Clindamycin) Topical Gel, based on mg/m) revealed no effects on fertility or mating ability.
Animal reproduction studies have not been conducted with Duac (Clindamycin) Topical Gel or benzoyl peroxide. It is also not known whether Duac (Clindamycin) Topical Gel can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Duac (Clindamycin) Topical Gel should be given to a pregnant woman only if clearly needed.
Developmental toxicity studies performed in rats and mice using oral doses of clindamycin up to 600 mg/kg/day (240 and 120 times the amount of clindamycin in the highest recommended adult human dose based on mg/m, respectively) or subcutaneous doses of clindamycin up to 250 mg/kg/day (100 and 50 times the amount of clindamycin in the highest recommended adult human dose based on mg/m, respectively) revealed no evidence of teratogenicity.
Duac (Clindamycin) Adverse Reactions
During clinical trials, all patients were graded for facial erythema, peeling, burning, and dryness on the following scale: 0 = absent, 1 = mild, 2 = moderate, and 3 = severe. The percentage of patients that had symptoms present before treatment (at baseline) and during treatment were as follows:
(Percentages derived by # subjects with symptom score/# enrolled Duac (Clindamycin) Topical Gel subjects, n = 397).
Anaphylaxis, as well as allergic reactions leading to hospitalization, has been reported in post-marketing use with Duac (Clindamycin) Topical Gel. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to a drug exposure.
Duac (Clindamycin) Dosage And Administration
Duac (Clindamycin) Topical Gel should be applied once daily, in the evening or as directed by the physician, to affected areas after the skin is gently washed, rinsed with warm water and patted dry.
Duac (Clindamycin) How Supplied
Duac (Clindamycin) (clindamycin, 1% - benzoyl peroxide, 5%) Topical Gel is available in:
©2010 Stiefel Laboratories, Inc.
Stiefel Laboratories, Inc.
Research Triangle Park, NC 27709
Rev. February 2011
Duac (Clindamycin) is a registered trademark of Stiefel Laboratories, Inc.
Duac (Clindamycin) Principal Display Panel
Each gram of Duac (Clindamycin) Topical Gel contains 10 mg (1%) clindamycin, as phosphate, and 50 mg (5%) benzoyl peroxide in a base consisting of carbomer homopolymer (type C), dimethicone, disodium lauryl sulfosuccinate, edetate disodium, glycerin, methylparaben, poloxamer 182, purified water, silicon dioxide, and sodium hydroxide.
1-888-784-3335 (STIEFEL).
Side effects associated with use of this product may be reported to this number.
Stiefel Laboratories, Inc.
Research Triangle Park, NC 27709
Duac (Clindamycin) is a registered trademark of Stiefel Laboratories, Inc.
© 2011 Stiefel Laboratories, Inc.
305385
Duac (Clindamycin) Principal Display Panel
Duac (Clindamycin) Principal Display Panel
Available in 45 gram tubes
Each gram of Duac (Clindamycin) Topical Gel contains 10 mg (1%) clindamycin, as phosphate, and 50 mg (5%) benzoyl peroxide in a base consisting of carbomer homopolymer (type C), dimethicone, disodium lauryl sulfosuccinate, edetate disodium, glycerin, methylparaben, poloxamer 182, purified water, silicon dioxide, and sodium hydroxide.
1-888-784-3335 (STIEFEL).
Side effects associated with use of this product may be reported to this number.
Stiefel Laboratories, Inc.
Research Triangle Park, NC 27709
Duac (Clindamycin) is a registered trademark of Stiefel Laboratories, Inc.
305382
