James J Leyden1. 1. Department of Dermatology, University of Pennsylvania, Philadelphia, PA, USA. jjleyden@mindspring.com
Abstract
OBJECTIVE: To quantify the antimicrobial effect of clindamycin phosphate 1.2% and tretinoin 0.025% gel and 1% clindamycin phosphate gel in patients with Propionibacterium acnes of varying sensitivity to clindamycin. DESIGN: Study 1 was an initial range-finding study that was neither blinded nor randomized. Study 2 was an open-label, randomized, splitface, single-center study. Both studies were conducted in Pennsylvania. PATIENTS: Study 1 (n=20) and study 2 (n=22) involved healthy patients aged 18 years or older with initial P acnes levels #104/cm2 and minimum inhibitory concentrations (MICs) #8 μg/mL forclindamycin. INTERVENTIONS: Study 1, clindamycin gel applied twice daily for 6 weeks. Study 2; once-daily application with the combination gel to one cheek and clindamycin gel to the other side for 6 weeks. MAIN OUTCOME MEASURE: The comparative effectiveness of each product vs P acnes of varying sensitivity to clindamycin at 3 and 6 weeks posttreatment. RESULTS: For study 1, at 3 and 6 weeks, clindamycin-treated patients with MICs of %256 μg/mL showed greater reductions than those with MICs #512 μg/mL (P=.0001). Study 2 showed a significant reduction in P acnes for both products, with no differences found. Clindamycin alone was more effective in vivo in patients with MIC levels of %256 μg/mL than patients with higher MIC levels. The combination product produced a greater reduction than clindamycin alone after 6 weeks in patients with high MICs #512 μg/mL (P=.0047). CONCLUSION: These studies suggest that 1% clindamycin alone produces a varying in vivo antimicrobial effect, with a breakpoint at %256 μg/mL. Use of clindamycin phosphate 1.2% and tretinoin 0.025% gel resulted in a significantly greater in vivo antimicrobial effect than clindamycin alone in patients carrying P acnes with MICs of #512 μg/mL (P=.0047).
RCT Entities:
OBJECTIVE: To quantify the antimicrobial effect of clindamycin phosphate 1.2% and tretinoin 0.025% gel and 1% clindamycin phosphate gel in patients with Propionibacterium acnes of varying sensitivity to clindamycin. DESIGN: Study 1 was an initial range-finding study that was neither blinded nor randomized. Study 2 was an open-label, randomized, splitface, single-center study. Both studies were conducted in Pennsylvania. PATIENTS: Study 1 (n=20) and study 2 (n=22) involved healthy patients aged 18 years or older with initial P acnes levels #104/cm2 and minimum inhibitory concentrations (MICs) #8 μg/mL for clindamycin. INTERVENTIONS: Study 1, clindamycin gel applied twice daily for 6 weeks. Study 2; once-daily application with the combination gel to one cheek and clindamycin gel to the other side for 6 weeks. MAIN OUTCOME MEASURE: The comparative effectiveness of each product vs P acnes of varying sensitivity to clindamycin at 3 and 6 weeks posttreatment. RESULTS: For study 1, at 3 and 6 weeks, clindamycin-treated patients with MICs of %256 μg/mL showed greater reductions than those with MICs #512 μg/mL (P=.0001). Study 2 showed a significant reduction in P acnes for both products, with no differences found. Clindamycin alone was more effective in vivo in patients with MIC levels of %256 μg/mL than patients with higher MIC levels. The combination product produced a greater reduction than clindamycin alone after 6 weeks in patients with high MICs #512 μg/mL (P=.0047). CONCLUSION: These studies suggest that 1% clindamycin alone produces a varying in vivo antimicrobial effect, with a breakpoint at %256 μg/mL. Use of clindamycin phosphate 1.2% and tretinoin 0.025% gel resulted in a significantly greater in vivo antimicrobial effect than clindamycin alone in patients carrying P acnes with MICs of #512 μg/mL (P=.0047).
Authors: James Q Del Rosso; Guy F Webster; Ted Rosen; Diane Thiboutot; James J Leyden; Richard Gallo; Clay Walker; George Zhanel; Lawrence Eichenfield Journal: J Clin Aesthet Dermatol Date: 2016-04-01