Clindamycin Phosphate Topical Solution, USP 1%

SECTION 2: Hazards identification

Dose and Administration Apply a thin film of Clindamycin phosphate topical solution, twice daily to affected area. Keep all liquid dosage forms in containers tightly closed. Adverse effects In 18 clinical studies of various formulations of Clindamycin phosphate using placebo vehicle and/or active comparator drugs as controls, patients experienced a number of treatment emergent adverse dermatologic events. Treatment Number of patients reporting events Emergent Solution Gel Gel Lotion Adverse n=553(%) n=148 N=160(%) Event Burning 62 (11) 15 (10) 17 (11) Itching 36 (7) 15 (10) 17 (11) Burning/Itchi 60 (11) # (-) ng Dryness 105 (19) 34 (23) 29 (18) Erythema 86 (16) 10 (7) 22 (14) Oiliness/Oily 8 (1) 26 (18) 12* (10) Skin peeling 61 (11) # (-) 11 (7) # not recorded * of 126 subjects Orally and parenterally administered clindamycin has been associated with severe colitis which may end fetally. Cases of diarrhea, bloody diarrhea and colitis (including pseudomembranous colitis) have been reported as adverse reactions in patients treated with oral and parenteral formulation of clindamycin and rarely with topical clindamycin. Abdominal pain, gastrointestinal disturbances, gram-negative folliculitis, eye pain and contact dermatitis have also been reported in association with the use of topical formulations of clindamycin. Over Dose Effect Topically applied clindamycin phosphate can be absorbed in sufficient amount to produce systemic effects. 2 of 8 Pregnancy Comments

Teratogenic Effects

In clinical trials with pregnant women, the systemic administration of clindamycin during the second and third trimesters has not been associated with an increased frequency of congenital abnormalities. There are no adequate studies in pregnant women during the first trimester of pregnancy. Clindamycin should be used during first trimester of pregnancy only if clearly needed. Pharmacokinteics Following multiple topical applications of clindamycin phosphate at isopropyl alcohol and water solution, very low levels of clindamycin are present in the serum (0–3 ng/mL) and less than 0.2% of the dose is recovered in urine as clindamycin. Although clindamycin phosphate is inactive in vitro, rapid in vivo hydrolysis converts this compound to the antibacterially active clindamycin. Microbiology Clindamycin inhibits bacterial protein synthesis by binding to the 23S RNA of the 50S subunit of the ribosome. Clindamycin is bacteriostatic. Antimicrobial Activity Clindamycin is active in vitro against most isolates of Propionibacterium acnes; however, the clinical significance is unknown. Resistance Resistance to clindamycin is most often caused by modification of specific bases of the 23S ribosomal RNA. Cross-resistance between clindamycin and lincomycin is complete. Because the binding sites for these antibacterial drugs overlap, cross resistance is sometimes observed among lincosamides, macrolides and streptogramin B. Macrolideinducible resistance to clindamycin occurs in some isolates of macrolide-resistant bacteria. 3 of 8