Pharmacotherapeutic group: (nitro) imidazole derivatives
ATCvet code: QP51AA01
Pharmacodynamic properties
After metronidazole has penetrated the bacteria the molecule is reduced by the sensitive bacteria (anaerobe). The metabolites that are created have a toxic effect on the bacteria through binding to the bacterial DNA. In general metronidazole is bactericidal for sensitive bacteria in concentrations equal to or a little higher than the minimum inhibiting concentration (MIC).
Clinically metronidazole does not have any relevant effect on facultative anaerobes, obligate aerobes and microaerophilic bacteria.
Pharmacokinetic particulars
Metronidazole is immediately and well absorbed after oral administration. The peak plasma concentration, Cmax was reached in dogs at between 0.75 and 2 hours after dosing and in cats at between 0.33 and 2 hours after dosing. The average terminal half life was 6.35 hours in dogs and 6.21 hours in cats. Metronidazole penetrates well into the tissues and bodily fluids, such as saliva, milk, vaginal secretions and semen. Metronidazole is primarily metabolised in the liver. Within 24 hours after oral administration, 35-65% of the administered dose (metronidazole and the metabolites thereof) is excreted in the urine.