Tinidazole--microbiology, pharmacology and efficacy in anaerobic infections.

Tinidazole is a 5-nitroimidazole with selective activity against anaerobic bacteria and protozoa. It is bactericidal at low concentrations and its spectrum covers most anaerobic bacteria and some capnophilic microorganisms. Anaerobic bacteria known to be resistant to tinidazole include anaerobic streptococci, actinomyces and propionibacteria. Tinidazole is one of the most active antibacterial agents against Bacteroides fragilis which is one of the most resistant species of anaerobic bacteria. Only a few strains have been reported to be resistant. Tinidazole has been shown to be efficacious in protozoal infections such as trichomonal vaginitis, amoebiasis and giardiasis. Clinical studies have also shown that tinidazole is efficacious in the treatment of anaerobic infections including respiratory tract infections, intra-abdominal sepsis and obstetrical and gynecological infections. Since tinidazole has no activity against aerobic bacteria, it must be combined with other antibacterial agents in the treatment of mixed infections involving aerobic and anaerobic bacteria. Tinidazole has also been used successfully alone or in combination with other antimicrobial agents for prophylaxis in patients undergoing elective colonic and abdominal surgery, emergency appendectomy and gynecological surgery.