CLINDAMYCIN PHOSPHATE

Clindamycin Phosphate Foam contains clindamycin (1%) as clindamycin phosphate, USP. Clindamycin phosphate, USP 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. The chemical name for clindamycin phosphate, USP is methyl 7-chloro-6,7,8-trideoxy-6-(1-methyl- trans -4-propyl-L-2-pyrrolidinecarboxamido)-1-thio-L- threo -α-D- galacto -octopyranoside 2-(dihydrogen phosphate). The structural formula for clindamycin phosphate, USP is represented below: Molecular Formula: C 18 H 34 ClN 2 O 8 PS Molecular Weight: 504.96 g/mol Clindamycin Phosphate Foam contains clindamycin (1%) as clindamycin phosphate, USP at a concentration equivalent to 10 mg clindamycin per gram in a thermolabile hydroethanolic foam vehicle consisting of cetyl alcohol, ethanol (58%), polysorbate 60, propylene glycol, purified water, and stearyl alcohol pressurized with a hydrocarbon (propane/butane) propellant. structure.jpg

Clindamycin phosphate foam is indicated for topical application in the treatment of acne vulgaris in patients 12 years and older. Clindamycin phosphate foam is a lincosamide product indicated for acne vulgaris in patients 12 years and older. ( 1 )

Clindamycin phosphate foam is for topical use only, and not for oral, ophthalmic, or intravaginal use. Apply clindamycin phosphate foam once daily to affected areas after the skin is washed with mild soap and allowed to fully dry. Use enough to cover the entire affected area. If there has been no improvement after 6 to 8 weeks or if the condition becomes worse, treatment should be discontinued. The contents of clindamycin phosphate foam are flammable; avoid fire, flame and/or smoking during and immediately following application. • For topical use only; not for oral, ophthalmic, or intravaginal use. ( 2 ) • Apply clindamycin phosphate foam once daily to affected areas. ( 2 ) • Flammable; avoid fire, flame and/or smoking during and immediately following application. ( 2 )

Clindamycin phosphate foam is contraindicated in individuals with a history of regional enteritis or ulcerative colitis, or a history of antibiotic-associated colitis (including pseudomembranous colitis). Clindamycin phosphate foam is contraindicated in individuals with a history of regional enteritis or ulcerative colitis, or a history of antibiotic-associated colitis (including pseudomembranous colitis). ( 4 )

The most common adverse reactions (>1%) are headache and application site reactions including burning, pruritus, and dryness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Glenmark Pharmaceuticals Inc., USA at 1 (888) 721-7115 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. A total of 439 subjects with mild to moderate acne vulgaris were treated once daily for 12 weeks with clindamycin phosphate foam. The incidence of adverse reactions occurring in ≥ 1% of the subjects in clinical trials comparing clindamycin phosphate foam and its vehicle is presented in Table 1. Table 1: Adverse Reactions Occurring in ≥ 1% of Subjects Adverse Reactions Number (%) of Subjects Clindamycin Phosphate Foam Vehicle Foam N = 439 N = 154 Headache 12 (3%) 1 (1%) Application site burning 27 (6%) 14 (9%) Application site pruritus 5 (1%) 5 (3%) Application site dryness 4 (1%) 5 (3%) Application site reaction, not otherwise specified 3 (1%) 4 (3%) In a contact sensitization study, none of the 203 subjects developed evidence of allergic contact sensitization to clindamycin phosphate foam. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of clindamycin phosphate foam: application site pain, application site erythema, diarrhea, urticaria, abdominal pain, hypersensitivity, rash, abdominal discomfort, nausea, seborrhea, application site rash, dizziness, pain of skin, colitis (including pseudomembranous colitis), and hemorrhagic diarrhea. 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 drug exposure. Abdominal pain and gastrointestinal disturbances, as well as gram-negative folliculitis, have also been reported in association with the use of topical formulations of clindamycin. Orally and parenterally administered clindamycin have been associated with severe colitis, which may end fatally.

7.1 Erythromycin Clindamycin phosphate foam should not be used in combination with topical or oral erythromycin-containing products due to possible antagonism to its clindamycin component. In vitro studies have shown antagonism between these two antimicrobials. The clinical significance of this in vitro antagonism is not known. 7.2 Neuromuscular Blocking Agents Clindamycin has been shown to have neuromuscular blocking properties that may enhance the action of other neuromuscular blocking agents. Therefore, clindamycin phosphate foam should be used with caution in patients receiving such agents.