antimicrobial and antiprotozoal agent.
Antiprotozoal and antibacterial drug derived from 5-nitroimidazole. The mechanism of action consists in the biochemical reduction of the 5-nitro group of metronidazole by intracellular transport proteins of anaerobic microorganisms and protozoa. The reduced 5-nitro group of metronidazole interacts with the DNA of the cell of microorganisms, inhibiting the synthesis of their nucleic acids, which leads to the death of bacteria.
Active against Trichomonas vaginalis, Entamoeba histolytica, as well as gram-negative anaerobes Bacteroides spp. (including B. fragilis, B. distasonis, B. ovatus, B. thetaiotaomicron, B. vulgatus), Fusobacterium spp. and some gram-positive anaerobes (sensitive strains Eubacterium spp., Clostridium spp., Peptococcus niger, Peptostreptococcus spp.). The MIC for these strains is 0.125-6.25 μg / ml.
Aerobic microorganisms and facultative anaerobes are insensitive to metronidazole, but in the presence of mixed flora (aerobes and anaerobes), metronidazole acts synergistically with antibiotics effective against conventional aerobes.
After intravaginal administration, it undergoes systemic absorption (about 56%).
The relative bioavailability of the vaginal gel is 2 times higher than the bioavailability of a single dose (500 mg) of vaginal metronidazole tablets.
Penetrates into breast milk and most tissues, passes through the BBB and the placenta. The connection with plasma proteins is less than 20%. It is metabolized in the liver by hydroxylation, oxidation and glucuronidation. The activity of the main metabolite (2-oxymetronidazole) is 30% of the activity of the parent compound. TCmax (237 ng / ml) vaginal gel - 6-12 hours
It is excreted by the kidneys - 60-80% of the dose of the systemic drug (20% of this amount unchanged), by the intestines - 6-15% of the dose of the systemic drug.
Urogenital trichomoniasis (including urethritis, vaginitis), nonspecific vaginitis of various etiologies, confirmed by clinical and microbiological data.
Hypersensitivity (including to nitroimidazole derivatives), leukopenia, impaired coordination of movements, organic lesions of the central nervous system (including epilepsy), liver failure (in the case of large doses), pregnancy (I trimester), lactation.
Carefully. Pregnancy (II-III trimesters), history of leukopenia.
Allergic reactions: urticaria, skin rash.
Local reactions: a burning sensation or irritation of the penis in a sexual partner, a burning sensation or frequent urination, vulvitis (itching, burning pain or hyperemia of the mucous membrane in the external genital area).
Systemic effects may develop: changes in taste, including a "metallic" taste, dizziness, headache, dryness of the oral mucosa, nausea, vomiting, loss of appetite, spastic abdominal pain, constipation or diarrhea, dark urine staining, leukopenia or leukocytosis.
After discontinuation of the drug - the development of vaginal candidiasis.
Similar to disulfiram, it causes intolerance to ethanol.
Simultaneous use with disulfiram can lead to the development of various neurological symptoms (you should not prescribe metronidazole to patients who have taken disulfiram within the last 2 weeks).
Enhances the effect of indirect anticoagulants (warfarin), it is not recommended to combine with non-depolarizing muscle relaxants (vecuronium bromide).
When taken simultaneously with Li + preparations, the concentration of the latter in the plasma may increase.
Phenobarbital accelerates the metabolism of metronidazole by inducing microsomal liver enzymes; cimetidine - reduces, which can lead to an increase in its concentration in the serum and an increase in the risk of side effects.
How to take, course of administration and dosage
Intravaginally, once 2 g or as a course of treatment, 500 mg / day 2 times a day (morning and evening) for 10 days.
During the course of treatment, sexual intercourse should be avoided.
Symptoms: nausea, vomiting, ataxia.
Treatment: no specific antidote, symptomatic and supportive therapy.
Simultaneous treatment of sexual partners is recommended.
When treating Trichomonas vaginitis in women and Trichomonas urethritis in men, it is necessary to refrain from sexual intercourse.
With vaginitis caused by Trichomonas vaginalis, it is advisable to simultaneously treat the sexual partner with oral metronidazole.
In the case of using the drug together with metronidazole for oral administration, especially with a repeated course, it is necessary to control the picture of peripheral blood (risk of leukopenia).
During the treatment period, ethanol is contraindicated (disulfiram-like reactions may develop: abdominal pain of a spastic nature, nausea, vomiting, headache, sudden flushing of the face).