Metronidazole, 5 mg/ml 100 ml

An antiprotozoal and antimicrobial drug, a derivative of 5-nitroimidazole. Mechanism of action consists in biochemical reduction of 5-nitrogroup of intracellular transport proteins of anaerobic microorganisms and protozoa. The reduced 5-nitrogroup interacts with the DNA of the microbial cell, inhibiting the synthesis of their nucleic acids, which leads to the death of the bacteria.

It is active against Trichomonas vaginalis, Entamoeba histolytica as well as obligate anaerobes Bacteroides spp. (including Bacteroides fragilis, Bacteroides distasonis, Bacteroides ovatus, Bacteroides thetaiotaomicron, Bacteroides vulgatus), Fusobacterium spp, some gram-positive microorganisms (Eubacterium spp., Clostridium spp., Peptococcus niger, Peptostreptococcus spp.).

The minimum suppressive concentration 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).

Metronidazole is insensitive to aerobic microorganisms and facultative anaerobes, but in the presence of mixed flora (aerobes and anaerobes) metronidazole acts synergistically with antibiotics effective against common aerobes.

It increases the sensitivity of tumors to radiation, causes sensitization to alcohol (disulfiram-like action).

Indications

Active ingredient

Composition

1 vial metronidazole 5 mg

Supplementary substances:

Sodium chloride 900 mg,

sodium dihydrophosphate dihydrate (sodium phosphoric acid displaced 2-water) 300 mg,

water d/i (up to 100 ml).

How to take, the dosage

Intravenous

Intravenous administration is indicated in severe infections and when oral administration is not possible.

In adults and children over 12 years old a single dose is 500 mg, the rate of IV continuous (streaming) or drip infusion is 5 ml/min. The interval between injections is 8 hours. Duration of treatment course is determined individually. Maximum daily dose is not more than 4 g. By indications, depending on the nature of the infection, transition to maintenance therapy with oral forms of metronidazole is carried out.

In children under 12 years of age 7.5 mg/kg body weight is administered in 3 doses at a rate of 5 ml/min.

For prevention of anaerobic infection before elective pelvic and urinary tract surgery in adults and children over 12 years old the drug is prescribed as an infusion in a dose of 500-1000 mg on the day of surgery, and the next day in a dose of 1500 mg/day (500 mg every 8 hours). After 1-2 days, the patient usually switches to maintenance therapy with oral forms of metronidazole.

For patients with significant renal dysfunction (creatinine Cl less than 30 ml/min) and/or liver, the daily dose is 1000 mg (frequency of administration – 2 times).

Interaction

In concomitant use with antacids containing aluminum hydroxide, with colestyramine absorption of metronidazole from the gastrointestinal tract is slightly reduced.

In concomitant use metronidazole potentiates the effect of indirect anticoagulants.

Simultaneous use with disulfiram may cause acute psychosis and impairment of consciousness.

An increase in plasma concentrations of carbamazepine and an increased risk of developing toxic effects when used concomitantly with metronidazole cannot be excluded.

Concomitant use with lansoprazole may cause glossitis, stomatitis and/or dark coloration of tongue; with lithium carbonate – possible increase of lithium concentration in blood plasma and development of intoxication symptoms; with prednisone – metronidazole excretion increases due to accelerated metabolism in liver under the influence of prednisone. There may be a decrease in the effectiveness of metronidazole.

Concomitant use with rifampicin increases clearance of metronidazole from the body; with phenytoin – there may be a slight increase in plasma concentrations of phenytoin; there has been described a case of development of toxic effect.

Concomitant use with phenobarbital significantly increases excretion of metronidazole from the body, apparently due to the acceleration of its metabolism in the liver under the influence of phenobarbital. The effectiveness of metronidazole may be reduced.

Concomitant use with fluorouracil increases toxic effects, but not the effectiveness of fluorouracil.

A case of acute dystonia after a single dose of chloroquine in a patient receiving metronidazole has been described.

Concomitant use with cimetidine may inhibit the metabolism of metronidazole in the liver, which may lead to delayed excretion and increased plasma concentrations.

Concomitant use of ethanol in patients receiving metronidazole may result in disulfiram-like reactions.

Special Instructions

Ethanol intake is contraindicated during treatment (development of disulfiram-like reaction is possible: spastic abdominal pain, nausea, vomiting, headache, sudden rush of blood to the face).

In combination with amoxicillin it is not recommended to use in patients under 18 years of age.

When prolonged therapy the blood count should be monitored. In case of leukopenia the possibility of continuing treatment depends on the risk of developing an infectious process.

The occurrence of ataxia, dizziness and any other deterioration in the neurological status of patients requires discontinuation of treatment.

It may immobilize treponemes and lead to a false positive Nelson’s test.

Darkens urine.

When treating trichomonas vaginitis in women and trichomonas urethritis in men, it is necessary to abstain from sexual activity. The simultaneous treatment of sexual partners is mandatory. The treatment does not stop during menstruation. After the therapy of trichomoniasis should be tested for three consecutive cycles before and after menstruation.

After treatment of giardiasis, if symptoms persist, three stool tests at intervals of several days should be performed after 3-4 weeks (some successfully treated patients may have lactose intolerance caused by the infestation for weeks or months, resembling the symptoms of giardiasis).

Breastfeeding should be stopped during treatment.

Contraindications

With caution, use in the second and third trimesters of pregnancy.

Side effects

Digestive system disorders: nausea, vomiting, loss of appetite, intestinal colic, diarrhea, constipation, coated tongue, bitter, metallic taste in the mouth, stomatitis, dry mouth, glossitis, pancreatitis.

Hematopoietic system: reversible neutropenia (leukopenia).

CNS disorders: peripheral neuropathy (feeling of numbness of extremities), headaches, seizures, drowsiness, dizziness, movement coordination disorders, ataxia, confusion, depression, hyperexcitability, weakness, insomnia, hallucinations, irritability.

Allergic reactions: skin rash, urticaria, pruritus, erythema multiforme, angioedema and anaphylactic reaction, skin hyperemia, nasal congestion, fever, arthralgia.

Local reactions: thrombophlebitis may occur at the injection site (pain, hyperemia or swelling at the injection site).

Hepatobiliary system: increased activity of liver enzymes, cholestasis jaundice.

Minitorial system disorders: dysuria, cystitis, polyuria. urinary incontinence, candidiasis of the vaginal mucosa, staining of urine red-brown (caused by metabolite of metronidazole, not clinically relevant).

Others: increase in body temperature, flattening of the T tooth on the ECG.

Overdose

Symptoms: nausea, vomiting, ataxia; when taken as a radiosensitizer – seizures, peripheral neuropathy.

Treatment: no specific antidote, symptomatic and supportive therapy.

Similarities