Antibiotics in GynecologyJOURNAL OF GYNECOLOGIC SURGERYMary Ann Liebert, Inc., Publishers

ClindamycinNEWTON G. OSBORNE, M.D., Ph.D.

Clindamycin is A LINCOSAMIDE (7-chloro-7-deoxylincomycin) antibiotic that is clinically superior to theparent compound, lincomycin. Clindamycin is active against most gram-positive bacteria. It is,

however, inactive against Streptococcus faecalis.Clindamycin is used widely in obstetrics and gynecology. Gentamicin does not interfere with its activity

against sensitive staphylococci, streptococci, clostridia, or pneumococci. It may, in fact, act synergisticallywith clindamycin against certain gram-positive cocci, such as Streptococcus viridans.

Resistant staphylococci are not uncommon. For this reason, sensitivity testing is indicated. Except for theenterococci, streptococcal resistance is uncommon. Practically all aerobic gram-negative bacteria are

resistant to clindamycin.Although the antibacterial spectrum of clindamycin is similar to that of erythromycin, an important

difference for the gynecologist is the ineffectiveness of clindamycin against Neisseria gonorrhoeae.Clindamycin, however, has good inhibitory effect against organisms associated with bacterial vaginosis, suchas Gardnerella vaginalis. Application of a clindamycin vaginal cream for 7 days reportedly treats bacterialvaginosis effectively. '

Of clinical importance for gynecologists is the activity of clindamycin against anaerobic bacteria commonlyassociated with pelvic infection. Peptococci, peptostreptococci, and gram-negative anaerobes, such as

Bacteroides spp., are sensitive to clindamycin. However, plasmid-mediated resistance has emerged in some

institutions.2 Fortunately, metronidazole and chloramphenicol, along with some of the second-generationcephalosporins, Imipenem, and a few ß-lactam antibiotics in combination with ß-lactamase-resistantcompounds, are active against some of the anaerobes of importance in pelvic infections. Clindamycin has theadvantage of retaining its activity even in lower pH ranges such as are found in abscesses. Clindamycin can beadministered orally in a dosage of up to 450 mg every 6 hours for serious infections. The adult parenteraldosage is 900 mg every 8 hours when given in combination with an aminoglycoside, such as gentamicin.Clindamycin's main excretion route is the liver. Therefore, an adjustment in dosage is not necessary forpatients with mild to moderate renal failure.Clindamycin acts on the 50S subunit of bacterial ribosomes to inhibit protein synthesis. The main side

effects are nausea, vomiting, abdominal cramps, and diarrhea. Pseudomembranous colitis is the most severemanifestation of a disease spectrum of which the most common manifestation is self-limiting diarrhea. Bothoral and parenteral clindamycin can induce pseudomembranous colitis. This most severe side effect seems tobe more common in older patients and in patients who have undergone abdominal surgery.

Pseudomembranous colitis has been associated with the use of several antibiotics but not with vancomycin.Two toxins from Clostridium difficile are involved in the pathophysiology of pseudomembranous colitis.Clostridium difficile is sensitive to metronidazole, sulfonamides, and vancomycin. The organism is able to

sporulate under adverse conditions. This property may be responsible for the reported cases of relapse.Drug fever with eosinophilia as well as rash can occur with clindamycin therapy. Drug fever must be

considered in cases of persistent fever for which there is no explanation.Clindamycin seldom is used as a single agent in patients with pelvic infection. It is used commonly in

association with ampicillin and an aminoglycoside—the so-called triple therapy.

Creighton University School of Medicine, Omaha, Nebraska.

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198 Osborne Journal of Gynecologic Surgery

REFERENCES

1. Livengood CH III, Thomason JL, Hill GB. Bacterial vaginosis: Diagnostic and pathogenetic findings during topicalclindamycin therapy. Am J Obstet Gynecol 1990; 163:515.

2. Soriano F, Ponte C, Wilhelmi I. Increasing incidence of clinical isolates of Bacteroides fragilis resistant to

clindamycin. J Antimicro Chemother 1984:13:395.

Address reprint requests to:Newton G. Osborne, M.D., Ph.D.

Department of OBIGYN601 North 30th Street

Suite 4810Omaha, NE 68131