Description
Metronidazole-Renewal Pharmacodynamics
Metronidazole is a derivative of 5-nitroimidazole. The mechanism of action of metronidazole consists in biochemical reduction of the 5-nitrogroup of metronidazole by intracellular transport proteins of anaerobic microorganisms and protozoa. The reduced 5-nitrogroup of metronidazole interacts with the DNA of the microbial cell, inhibiting the synthesis of their nucleic acids, which leads to the death of the microorganisms.
It is active against Trichomonas vaginalis, Entamoeba histolytica, as well as gram-negative anaerobes Bacteroides spp. (including B. fragilis, B. ovatus, B. distasonis, B. thetaiotaomicron, B. vulgatus), Fusobacterium spp. and some gram-positive anaerobes (sensitive strains of Eubacterium spp, Clostridium spp., Peptococcus niger, Peptostreptococcus spp.). Minimum inhibitory concentration (MIC) for these strains is 0.125-6.25 µg/ml.
In combination with amoxicillin it shows activity against Helicobacter pylori (amoxicillin suppresses development of resistance to metronidazole).
Aerobic microorganisms and facultative anaerobes are not sensitive to metronidazole, but in the presence of mixed flora (aerobes and anaerobes) metronidazole acts synergistically with antibiotics effective against common aerobes.
Indications
– Protozoal infections: extraintestinal amoebiasis (including amebic liver abscess), intestinal amoebiasis (amebic dysentery), trichomoniasis.
– Infections caused by Bacteroides spp. (including B. fragilis, B. distasonis,B. ovatus, B. thetaiotaomicron, B. vulgatus); bone and joint infections; central nervous system (CNS) infections, including meningitis, brain abscess; bacterial endocarditis; pneumonia, empyema and lung abscess; sepsis.
– Infections caused by Clostridium spp., Peptococcus niger, Peptostreptococcus spp.: abdominal infections (peritonitis, liver abscess), pelvic infections (endometritis, fallopian tube and ovarian abscess, vaginal infections).
– Pseudomembranous colitis associated with antibiotic use.
– Gastritis or duodenal ulcer associated with Helicobacter pylori (as part of complex therapy).
– Prevention of postoperative complications (especially after operations on the colon, pararectal area, appendectomy, gynecological operations).
Contraindications
Hypersensitivity to metronidazole, other nitroimidazole derivatives, imidazole and other components of medicine; CNS disorders (including epilepsy); leukopenia (including in anamnesis); liver failure (in case of high doses); pregnancy, lactation; children under 6 years old.
Caution
Hepatic encephalopathy; acute and chronic peripheral and central nervous system disorders (risk of increased neurological symptoms); renal failure.
Administration during pregnancy and lactation
Since metronidazole crosses the placental barrier and its effect on human fetal organogenesis is unknown, use of the drug Metronidazole Reneval is contraindicated during pregnancy.
Metronidazole penetrates into the breast milk, therefore it is contraindicated during breast-feeding.
Dosage and administration
- Metronidazole is taken orally, before or after meals, with plenty of water.
- In intestinal amebiasis, metronidazole is used in a daily dose of 1500 mg (divided into 3 doses) for 7 days.
- In acute amebic dysentery, the daily dose is 2250 mg (divided into 3 doses). Children from 6 to 15 years of age are prescribed a daily dose of 500 mg (divided into 2 doses).
- In liver abscess and other extraintestinal forms of amebiasis, the maximum daily dose is 2500 mg (divided into 3 doses) for 3-5 days, in combination with tetracycline antibiotics and other therapies. Children from 6 to 15 years of age are prescribed a daily dose of 500 mg (divided into 2 doses).
- In trichomoniasis in women (urethritis and vaginitis) metronidazole is indicated as a single dose of 2 g or as a course treatment of 250 mg twice daily for 10 days.
- In trichomoniasis in men (urethritis) metronidazole is prescribed as a single dose of 2 g or as a course treatment of 250 mg 2 times daily for 10 days.
- Treatment of anaerobic infections usually begins with intravenous infusions followed by conversion to tablets. For adults, the drug dose is 500 mg 3 times a day. The duration of treatment is up to 7 days.
- For treatment of pseudomembranous colitis, metronidazole is prescribed 500 mg 3-4 times a day. The duration of treatment is determined by the doctor.
- For eradication of Helicobacter pylori, metronidazole is prescribed 500 mg 3 times daily in combination therapy (for example, with amoxicillin).
- To prevent postoperative complications, metronidazole is prescribed in a daily dose of 750-1500 mg (divided into 3 doses) 3-4 days before surgery. One to two days after surgery (when oral administration is already allowed), metronidazole is prescribed at 750 mg per day for 7 days.
