Ornidazole 500mg contains the active ingredient ornidazole and is indicated for the treatment of various bacterial and parasitic infections, such as amoebic infections of the liver and intestines, and giardiasis… Let's learn about the uses and usage of Ornidazole through the article below.
1. What is Ornidazole?
Ornidazole 500mg medicine containing the active ingredient Ornidazole is indicated in the treatment of the following diseases:
- Bacterial and parasitic infections caused by germs that are sensitive to the drug, such as infections from anaerobic bacteria in medical or surgical settings and as a preventive measure for surgical infections.
- Infections caused by parasites like Trichomonas, amoeba in the liver and intestines, and Giardia.
Pharmacodynamics:
- Ornidazole, a 5-nitroimidazole derivative, exhibits activity against anaerobic bacteria and parasites. The drug functions by being reduced to form cytotoxic products that interact with microbial DNA, disrupting its helical structure. This results in the inhibition of protein synthesis and ultimately leads to the death of susceptible microorganisms. Ornidazole has demonstrated activity against Giardia intestinalis, Entamoeba histolytica, and Trichomonas vaginalis.
Pharmacokinetics:
- Absorption: Ornidazole is rapidly absorbed from the gastrointestinal tract (approximately 90%) and reaches peak plasma concentrations within 3 hours. With repeated 500mg doses every 12 hours, peak and trough plasma concentrations are approximately 14 mcg/mL and 6 mcg/mL, respectively.
- Distribution: Less than 15% of Ornidazole is bound to plasma proteins. The drug is widely distributed throughout body tissues, fluids, and even cerebrospinal fluid.
- Metabolism: Ornidazole is metabolized in the liver to form α-hydroxymethyl and 2-hydroxymethyl metabolites.
- Elimination: The elimination half-life of Ornidazole is approximately 13 hours. Approximately 85% of a single dose is excreted within the first 5 days, primarily in the form of metabolites. Excretion occurs mainly via the urine as metabolites and to a lesser extent in the feces. The drug and its metabolites are also partially excreted in bile.
2. Dosage of Ornidazole 500mg
The dosage of Ornidazole 500mg depends on the age and condition of the patient, specifically as follows:
2.1. Dosage in adults
Amoebiasis:
- Take 500mg/time x 2 times/day for 5-10 days. In some cases, patients can take a single dose of 1.5g in 3 days of treatment. Another use in patients weighing over 60kg is to take 1g/time x 2 times/day for 3 days;
- Patients with severe amoebic dysentery and amoebic liver abscess can take the drug intravenously, the starting dose is usually 0.5 - 1g. Then maintain a dose of 500mg every 12 hours for 3-6 days in combination with purulent drainage in the liver;
- Giardia disease: Take a single dose of Ornidazole 1g or 1.5g for 1-2 days.
Diseases caused by Trichomoniasis:
- Take a single dose of Ornidazole 1.5g or divide a course of treatment for 5 days with a dose of 500mg/time x 2 times/day;
- Treat both spouses or sexual partners.
Treatment of infections caused by anaerobic bacteria:
- Administer intravenously with a starting dose of 0.5 - 1g, followed by a single dose of 1g/day or 500mg/time x 2 times/day within 5 - 10 days;
- In case the patient's condition is stable, it can be replaced by oral therapy with a dose of 500mg/time x 2 times/day.
Treatment of infections caused by anaerobic bacteria after surgery:
- Administer the drug intravenously with a dose of 1g 30 minutes before surgery;
- Or take 1.5g 12 hours before surgery, then 500mg every 12 hours for 3-5 days after surgery.
2.2. Dosage in children
Children weighing more than 35kg use the same dose as adults. For children weighing less than 35kg, the dose is as follows:
Treatment of amoebic diseases:
- Single dose of 25 mg/kg for 5-10 days;
- Children with amoebic dysentery can receive a single dose of 40 mg/day for 3 consecutive days;
- Children with severe amoebic dysentery and amoebic liver abscess can use Ornidazole intravenously at a dose of 20-30 mg/kg/day for 3-6 days.
Treatment of diseases caused by Giardia: Use a single dose of 30-40 mg/kg for 1-2 days.
Treatment of diseases caused by Trichomonas: Use a single dose of 25 mg/kg.
Treatment of infections caused by anaerobic bacteria:
- Administer intravenously at a dose of 10 mg/kg, repeat the dose after 12 hours for a period of 5 - 10 days or use an oral dose of 20 - 30 mg/kg;
- Prophylaxis of infections caused by anaerobic bacteria after surgery: Oral or intravenous dose of 20 - 30 mg/kg before 12 hours of surgery and after surgery. Repeat dose after 12 hours for 3 days.
2.3. Dosage in Special Populations
- Patients with Hepatic Impairment: The half-life of Ornidazole 500mg is longer in patients with hepatic impairment, so twice the interval between doses is required in patients with hepatic impairment.
- Patients with renal failure: Most patients with renal impairment do not need to adjust the dose, except in the case of patients undergoing hemodialysis requiring an additional dose of Ornidazole before performing the procedure.
3. The side effects of Ornidazole 500mg
Some side effects when taking Ornidazole 500mg are as follows:
- Common side effects: Nausea, digestive disorders, loss of appetite, unpleasant metallic taste, vomiting, constipation or diarrhea;
- Uncommon side effects: Itching, skin rash, urticaria, cholestatic hepatitis, increased liver enzyme values, jaundice, pancreatitis;
- Rare side effects: Erythema multiforme, angioedema, colitis, diplopia, myalgia, arthralgia, agranulocytosis, thrombocytopenia, pancytopenia, anaphylaxis;
- Side effects of unknown frequency: Thrombophlebitis, muscle weakness, ataxia, dizziness, somnolence, hallucinations, numbness or tingling of extremities, glossitis, thrush, dark urine.
4. Precautions when using Ornidazole 500mg
4.1. Contraindications to the use of Ornidazole 500mg
The use of Ornidazole is contraindicated in people with hypersensitivity to imidazole derivatives or to any of its ingredients.
4.2. General precautions:
- General precautions: Discontinue Ornidazole if you experience confusion, dizziness, or loss of coordination. Patients should have regular blood tests, especially if taking the drug for a prolonged period or if they have a history of blood disorders.
- Pregnancy: Ornidazole should not be used during pregnancy unless necessary and under the strict supervision of a physician.
- Breastfeeding: Ornidazole should not be used during breastfeeding unless it is absolutely necessary.
- Driving and operating machinery: Ornidazole may cause dizziness and confusion. Therefore, it is not advisable to drive or operate machinery after taking this medication.
5. Drug interactions
Ornidazole 500mg drug can cause some interactions as follows:
Drug-drug interactions:
- Concurrent use of Ornidazole and Disulfiram may lead to acute confusion or psychosis.
- Concomitant use of Ornidazole and coumarin anticoagulants may enhance the anticoagulant effect.
- Concurrent use of Ornidazole and vecuronium bromide may prolong muscle relaxation time.
Drug-food interactions:
- Concurrent use of Ornidazole and alcohol may lead to disulfiram-like reactions in some patients.
The above information provides an overview of the uses, dosage, and precautions associated with Ornidazole. To ensure safety and efficacy, patients should use the medication as directed by their doctor or pharmacist.
To arrange an appointment, please call … or make your reservation directly HERE. You may also download the MyVinmec app to schedule appointments faster and manage your reservations more conveniently.
