Ornidazole

INSTRUCTIONS FOR MEDICAL USE OF THE MEDICINAL PRODUCT ORNIDAZOLE (Ornidazole)

Composition:

Active substance: ornidazole;

100 ml of solution contain ornidazole (calculated as 100% dry substance) 500 mg;

Excipients: sodium chloride, disodium edetate, diluted hydrochloric acid, sodium hydroxide, water for injections.

Medicinal form. Infusion solution.

Main physicochemical properties: clear colorless or slightly yellow liquid.

Pharmacotherapeutic group. Antibacterial agents for systemic use. Imidazole derivatives. ATC code J01X D03.

Pharmacological Properties

Pharmacodynamics

The mechanism of action of ornidazole is associated with disruption of DNA structure in microorganisms sensitive to it. Ornidazole is active against Trichomonas vaginalis, Entamoeba histolytica, Giardia lamblia (Giardia intestinalis), as well as certain anaerobic bacteria such as Bacteroides, Fusobacterium spp.; anaerobic bacteria: Clostridium spp., sensitive strains of Eubacterium spp.; anaerobic cocci: Peptococcus spp., Peptostreptococcus spp.

It readily penetrates microbial cells and, by binding to DNA, disrupts the replication process.

Pharmacokinetics

Ornidazole readily crosses the blood-brain and placental barriers, enters cerebrospinal fluid, bile, and penetrates into breast milk. After intravenous administration at a dose of 15 mg/kg and subsequent dosing of 7.5 mg per kg of body weight every 6 hours, steady-state concentrations range from 18–26 mcg/mL. Approximately 30–60% of the drug is metabolized in the body via hydroxylation, oxidation, and glucuronidation.

Elimination. Ornidazole is excreted primarily in the urine (60–80%), with nearly 20% excreted unchanged, and 6–15% in feces.

Clinical Characteristics.

Indications.

Parenteral administration of the drug is indicated in cases of acute and severe infection or when oral administration is not possible, for the following diseases and conditions:

• systemic anaerobic infections caused by microorganisms sensitive to ornidazole: septicemia, meningitis, peritonitis, postoperative wound infections, sepsis, septic abortion, and endometritis;
• prophylaxis of infections caused by anaerobic bacteria during surgical procedures (particularly surgeries on the colon and rectum), and gynecological operations;
• severe amoebic dysentery, all extraintestinal forms of amoebiasis, giardiasis, and hepatic abscess.

Contraindications.

Hypersensitivity to the components of the drug or to other nitroimidazole derivatives. Central nervous system (CNS) disorders, epilepsy, multiple sclerosis, chronic alcoholism. Circulatory disturbances, blood pathology or other hematological abnormalities.

Interaction with other medicinal products and other types of interactions.

Unlike other nitroimidazole derivatives, ornidazole does not inhibit aldehyde dehydrogenase and therefore is compatible with alcohol. However, ornidazole enhances the effect of oral anticoagulants of the coumarin group (warfarin), requiring appropriate dosage adjustment.

Ornidazole prolongs the muscle-relaxant effect of vecuronium bromide.

Concomitant use of phenobarbital and other enzyme inducers reduces the circulation period of ornidazole in blood serum, whereas enzyme inhibitors (e.g., cimetidine) increase it.

Special precautions for use.

When exceeding the recommended doses, there is a certain risk of developing adverse reactions in children, patients with liver impairment, and patients who abuse alcohol. When high doses of ornidazole are used or treatment lasts longer than 10 days, clinical and laboratory monitoring is recommended.

In patients with a history of blood disorders, monitoring of leukocytes is recommended, especially when repeated treatment courses are administered.

Exacerbation of central or peripheral nervous system disorders may occur during ornidazole therapy. If peripheral neuropathy, movement coordination disturbances (ataxia), dizziness, or impaired consciousness occur, treatment should be discontinued.

Exacerbation of candidiasis may occur, which requires appropriate treatment.

In the case of hemodialysis, the reduced elimination half-life should be taken into account, and additional doses of the drug should be administered before or after hemodialysis.

Concentrations of lithium salts, creatinine, and electrolytes should be monitored during lithium therapy.

The effect of other medicinal products may be increased or decreased during ornidazole treatment.

This medicinal product contains 15.43 mmol (or 354.7 mg) of sodium per 100 ml. Caution is advised when administering to patients on a sodium-restricted diet.

Use during pregnancy or breastfeeding.

Ornidazole is contraindicated during the first trimester of pregnancy. In the second and third trimesters, the drug should be used only if strictly indicated. If ornidazole use is necessary, breastfeeding should be discontinued.

Ability to affect reaction speed when driving or operating machinery.

During ornidazole use, symptoms such as somnolence, muscle rigidity, dizziness, tremor, seizures, impaired coordination, and transient loss of consciousness may occur. Patients should take into account the possibility of such effects when driving or operating machinery.

Dosage and Administration

The dosage and duration of treatment are determined by a physician depending on the nature of the disease and the treatment regimen.

The drug should be administered intravenously over 15–30 minutes.

For systemic anaerobic infections: in adults and children aged 12 years and older, the initial dose is 500–1000 mg, followed by 500 mg every 12 hours or 1000 mg every 24 hours for 5–10 days (stepwise dosing). Once the patient's condition has stabilized, oral administration of ornidazole should be initiated (e.g., 500 mg tablets, 1 tablet every 12 hours).

In children under 12 years of age with body weight exceeding 6 kg, the daily dose should be calculated at 20 mg/kg body weight, divided into 2 doses, administered over 5–10 days.

For prophylaxis of anaerobic infections during surgical procedures: in adults and children aged 12 years and older, ornidazole should be administered at a dose of 500–1000 mg 30 minutes before surgery.

To prevent mixed infections, ornidazole should be used in combination with aminoglycosides, penicillin, or cephalosporins. The drugs should be administered separately.

Severe amoebic dysentery, all extraintestinal forms of amoebiasis, giardiasis, liver abscess: in adults and children aged 12 years and older, the initial dose is 500–1000 mg, followed by 500 mg every 12 hours for 3–6 days.

In children under 12 years of age with body weight exceeding 6 kg, the daily dose should be calculated at 20–30 mg/kg body weight, divided into 2 doses.

In case of renal impairment, the interval between doses should be prolonged or the single and daily dose should be reduced.

Children.

Ornidazole is contraindicated in children with body weight less than 6 kg.

Overdose.

Symptoms: loss of consciousness, headache, dizziness, tremor, seizures, depression, peripheral neuritis, nausea, vomiting, anorexia, and possible exacerbation of symptoms of other adverse reactions.

Treatment: symptomatic; no specific antidote is known.

Adverse reactions.

Blood and lymphatic system disorders: signs of bone marrow suppression, moderate leukopenia, neutropenia.

Immune system disorders: hypersensitivity reactions, including anaphylactic shock, angioneurotic edema.

Skin and subcutaneous tissue disorders: skin rashes, urticaria, skin hyperemia, pruritus.

Nervous system disorders: dizziness, somnolence, headache, tremor, muscle rigidity, coordination disturbances, ataxia, seizures, transient loss of consciousness, confusion, signs of sensory or mixed peripheral neuropathy, excitement.

Gastrointestinal disorders: taste disturbances, metallic taste in the mouth, dry mouth, coated tongue, nausea, vomiting, dyspepsia, feeling of heaviness and tenderness in the epigastric region.

Hepatobiliary disorders: hepatotoxicity, changes in liver function tests.

General disorders and administration site conditions: increased body temperature; chills; general weakness; fatigue; dyspnea; changes at the injection site, including pain, redness, burning sensation at the injection site.

Other: darkening of urine color, cardiovascular disorders, including arterial hypotension.

Shelf life. 3 years.

Storage conditions. Store in the original packaging at a temperature not exceeding 25 °C, in a place inaccessible to children.

Incompatibility.

The drug must not be mixed with other injectable solutions during administration.

Packaging. 100 ml in a bottle; 1 bottle per carton.

Prescription status. Prescription only.

Manufacturer. Private Joint-Stock Company "Infuziya".

Manufacturer's address and location of business activity.

84A Nemirovskе Highway, Vinnytski Khotory village, Vinnytsia district, Vinnytsia region, 23219, Ukraine.