Ornazole

Generic composition: Ornidazole 

General Introduction

Ornazole is Ornidazole is a nitroimidazole derivative active against protozoa and anaerobic bacteria. It is effective against anaerobic enteric protozoa.  

Therapeutic category

• Anti-protozoal

Dosage forms available

• Ornidazole 500mg Tablets

Mechanism of action

Ornidazole is a bactericidal antibiotic which works by inhibition of protein synthesis by interaction with DNA. The nitro group in Ornidazole is responsible for its antibacterial property. Nitro group is converted to more active amine group and causes destruction of helical DNA structure. This is responsible for bacterial/protozoal cell death due to ornidazole.

Pharmacokinetics

Ornidazole tablets have mean absorption of about 90%. Peak plasma concentrations are reached within three hours. The half-life is about thirteen hours. 85% of a single dose is eliminated within the first five days, most of this being metabolized by liver and excreted in urine (63%) and feces (22%).

Uses

• Treatment of parasitic infections including amebiasis, trichomoniasis
• Bacterial vaginosis
• Giardiasis
• Anaerobic infections
• Prophylactic use in surgery

Dose

• Amoebiasis:   500mg twice daily for 5-10 days(Adult) and 25mg/Kg single daily dose for 5-10 days(pediatric)
• Amoebic dysentery:  1500 mg single daily dose for 3 days(>60 kg: 1000mg twice daily for 3 days) (Adult) and 40 mg/kg daily(Paediatric)
• Giardiasis: 1000-1500 mg single daily dose for 1-2 days (adult) and 30-40 mg/kg daily(pediatric)
• Trichomoniasis: 1500 mg single daily dose or 500 mg twice daily for 5 days and 25 mg/kg single dose(Pediatric)

Dose adjustment is needed in renal and hepatic impairment- supplemental dose may be needed. 

Drug interactions

 Coumarin-type oral anticoagulants (potentiates), Vercuronium bromide (prolongs muscle relaxant action)

Side effects

Common side effects of ornidazole are headaches, nausea, vomiting, dizziness, tremor, rigidity, poor coordination, seizures, tiredness, vertigo, peripheral neuropathy and skin reactions.

Precautions

• Alcohol: disulfiram type reaction may occur.
• Pregnancy and lactation
• Renal and hepatic impairment
• CNS diseases e.g. epilepsy or multiple sclerosis 

Contraindications

Hypersensitivity with ornidazole or other nitro imidazole derivatives