Metgyl Tablet

Metronidazole.

Each tablet contains: Metronidazole 400 mg.

Pharmacology: Pharmacodynamics: Mode or Mechanisms of Action: Antibacterial (systemic); antiprotozoal - Microbicidal; active against most obligate anaerobic bacteria and protozoa by undergoing intracellular chemical reduction via mechanisms unique to anaerobic metabolism. Reduced metronidazole, which is cytotoxic but short-lived, interacts with DNA to cause a loss of helical structure, strand breakage, and resultant inhibition of nucleic acid synthesis and cell death.
Metronidazole is very active against a wide range of pathogenic microorganisms especially species of bacteroides, fusobacteria, clostridia, eubacteria, anaerobic cocci and Gardnerella vaginalis.
It is also active against trichomonas, Entamoeba histolytica, Giardia lamblia and Balantidium coli.
Pharmacokinetics: Absorption: Well absorbed orally; bio-availability at least 80%.
Distribution: Distributed to saliva, bile, seminal fluid, breast milk, bone, liver and liver abscesses, lungs, and vaginal secretions; crosses the placenta and blood brain barrier, also.
Vol_D: ln adults: Approximately 0.55 l/kg.
Protein binding: Low (<20%).
Biotransformation: Hepatic.
Half-life: In adults: Normal liver function: 8 hours.
Time to peak serum concentration: 1 to 2 hours (oral).
Elimination: Renal: 60 to 80%; of this amount, approximately 20% excreted unchanged in urine.

Uro-genital trichomoniasis, both in woman (trichomonal vaginitis) and in men (trichomonal urethritis).
Non-specific vaginitis caused by pathogens susceptible to metronidazole.
All forms of amoebiasis, both intestinal and extra-intestinal.
Giardiasis.
Acute ulcerative gingivitis.
Anaerobically infected leg ulcers and pressure sores.
Acute dental infections (e.g., acute pericoronitis and acute apical infections).
Treatment and prevention of anaerobic infections.

Tablet should be swallowed, with frac12; glass of water, during or after a meal.
Anaerobic infections: The duration of a course is 7 days but it will depend upon the seriousness of the patient's condition as assessed clinically and bacteriologically.
Prophylaxis against anaerobic infections, chiefly in the context of abdominal (especially colorectal) and gynaecological surgery: Adult, 400 mg at 8-hourly interval. Children, 7.5 mg/kg every 8 hours.
Treatment of established anaerobic infections: Adult, 800 mg initially followed by 400 mg 8 hourly. Children, 7.5 mg/kg 8 hourly.
Treatment of Protozoal and other infection: (see table.)

Click on icon to see table/diagram/image

Symptoms: One case report of a voluntary overdose of 4200 mg in a 16-year-old pregnant woman reported that the patient developed disorientation which resolved without specific treatment. Larger doses than this reported overdose have been given to patients as a radiosensitizer without severe toxicity.
Treatment: Since there is no specific antidote, treatment for metronidazole overdose should be symptomatic and supportive.

During the first 3 months of pregnancy and during lactation; Patients known to be sensitive or hypersensitive to nitroimidazoles; Organic neurological disorders (CNS disorders); Blood dyscrasias or other anomalies of the blood picture; Concurrent use of ethyl alcohol; Severe hepatic failure.

Metronidazole should be used with great care in patients with blood dyscrasias or with active disease of the central nervous system. All patients receiving metronidazole for more than 10 days should be monitored and treatment discontinued if signs of peripheral neuropathy or CNS toxicity develop. Doses should be reduced in patients with severe liver disease.
In Trichomonas vaginalis infections, microscopic examination of the vaginal secretion should be performed to exclude the possibility of gonorrhoea.
An accompanying gonococcal infection may persist in a symptom-less form after Trichomonas vaginalis has been eliminated.
In patients undergoing haemodialysis, metronidazole and metabolites are efficiently removed during an 8-hour period of dialysis. Metronidazole therefore should be re-administered immediately after haemodialysis.
Use in Pregnancy/Reproduction: Studies in rats have not shown that metronidazole cause impaired fertility or birth defect in the foetus. Metronidazole, administered intraperitoneally to pregnant mice, has been shown to cause foeto-toxicity. When administered orally, no foetotoxicity was seen in pregnant mice. However, the use of metronidazole in the treatment of trichomoniasis is not recommended during the first trimester. Also, the 1-day course of therapy should not be used since this results in higher maternal and foetal serum concentrations.
Use in Lactation: Use is not recommended in nursing mothers since some studies in rats and mice have shown that metronidazole is carcinogenic and may cause adverse effects in the infant. However, use in the treatment of anaerobic bacterial infections or a short course of treatment with metronidazole for amoebiasis, severe periodontal infections, or trichomoniasis may be necessary in nursing mothers. During treatment with metronidazole, the breast milk should be expressed and discarded. Breast-feeding may be resumed 24 to 48 hours after treatment is completed.

Pregnancy/Reproduction: Studies in rats have not shown that metronidazole cause impaired fertility or birth defect in the foetus. Metronidazole, administered intraperitoneally to pregnant mice, has been shown to cause foeto-toxicity. When administered orally, no foetotoxicity was seen in pregnant mice. However, the use of metronidazole in the treatment of trichomoniasis is not recommended during the first trimester. Also, the 1-day course of therapy should not be used since this results in higher maternal and foetal serum concentrations.
Breast-feeding: Use is not recommended in nursing mothers since some studies in rats and mice have shown that metronidazole is carcinogenic and may cause adverse effects in the infant. However, use in the treatment of anaerobic bacterial infections or a short course of treatment with metronidazole for amoebiasis, severe periodontal infections, or trichomoniasis may be necessary in nursing mothers. During treatment with metronidazole, the breast milk should be expressed and discarded. Breast-feeding may be resumed 24 to 48 hours after treatment is completed.

The adverse effects of metronidazole are generally dose-related . The most common are gastro-intestinal disturbances, especially nausea and an unpleasant metallic taste; nausea is sometimes accompanied by headache, anorexia, and vomiting. Diarrhoea, dry mouth, a furred tongue, glossitis, and stomatitis may also occur.
Peripheral neuropathy, usually presenting as numbness or tingling in the extremities, and epileptiform seizures are serious adverse effects on the nervous system that have been associated especially with high doses of metronidazole or prolonged treatment. Weakness, dizziness, ataxia, drowsiness, insomnia and changes in mood or mental state such as depression or confusion have also been reported.
A moderate leucopenia has been reported in some patients but the white cell count has always returned to normal before or after treatment has been completed. Skin rashes and pruritus occur occasionally and anaphylaxis has been reported rarely.
Other side effects include urethral discomfort and darkening of the urine. Raised liver enzyme values have occasionally been reported.

Alcohol: It is recommended that metronidazole not be used concurrently with ingestion of alcohol; may result in disulfiram-like effects.
Anticoagulants, coumarin or indandione-derivative: Effects may be potentiated when these agents are used concurrently with metronidazole, periodic prothrombin time determinations may be required to determine if dosage adjustments of anticoagulants are necessary.
Cimetidine: Hepatic metabolism of metronidazole may be decreased when metronidazole and cimetidine are used concurrently, possibly resulting in delayed elimination and increased serum metronidazole concentrations.
Disulfiram: It is recommended that metronidazole not be used concurrently with, or for 2 weeks following, disulfiram in alcoholic patients; such use may result in confusion and psychotic reactions.
Lithium: Lithium concentrations may increase when metronidazole therapy is introduced; serum lithium and serum creatinine levels should be monitored several days after beginning metronidazole in order to detect impending lithium intoxication.
Phenobarbital: Phenobarbital may induce microsomal liver enzymes, increasing metronidazole's metabolism and resulting in a decrease in half-life and plasma concentration.
Phenytoin: Metronidazole may impair the clearance of phenytoin, increasing phenytoin's plasma concentration.
Aspartate amino transferase assay: It may give spuriously low values in patients taking metronidazole depending on the method used.

Auxiliary labelling: Avoid alcoholic beverages. May cause dizziness. Continue medicine for full time of treatment.

Store below 30°C, in a well-closed, light-resistant container.
Shelf-Life: 3 years.

Other Antibiotics

P01AB01 - metronidazole ; Belongs to the class of nitroimidazole derivatives antiprotozoals. Used in the treatment amoebiasis and other protozoal diseases.

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