Eriksson K, Larsson P-G, Nilsson M, Forsum U. Vaginal retention of locally administered clindamycin. APMIS 2011; 119: 373–6. Since bacterial vaginosis (BV) is characterized by a lack of, or very few, lactobacilli and high numbers of small, mostly anaerobic bacteria, an obvious
treatment modality would be eradication of the BV-associated bacterial flora followed by reintroduction of lactobacilli vaginally. As probiotic treatment with lactobacilli is one tool for improving the cure rate when treating BV, it is necessary to know the length of time after treatment that
clindamycin can be found in the vagina and if this could interfere with the growth of the probiotic lactobacilli. We evaluated the vaginal concentration of clindamycin in 12 women for 8 days to obtain data on the concentration of clindamycin in the vagina after intravaginal treatment
with the drug. The participants were examined five times between two menstrual periods: before treatment, the day after treatment was finished, and 3, 5 and 8 days post-treatment. The first day post-treatment clindamycin 0.46 × 10−3 to 8.4 × 10−3 g/g
vaginal fluid (median 2.87 × 10−3) was found. Thereafter, the concentration of clindamycin decreased rapidly. In 10 patients clindamycin was found after 3 days. A very low concentration was still present 5 days after treatment in four patients.
After 8 days no clindamycin was found. Clindamycin is rapidly eliminated from the vagina, within 3–8 days, after local administration. Our results indicate that treatment with probiotic lactobacilli could be problematic if carried out within 5 days after cessation
of clindamycin treatment.