Onydaz: Uses, Dosage, Side, Effects and Composition

Description and Composition of Onydaz

Onydaz is an antibiotic drug used in the treatment of mixed infections. Each film coated tablet contains Ofloxacin BP: 200 mg and Ornidazole: 500 mg as its active pharmaceutical ingredients. It also contains inactive ingredients called excipients in sufficient quantities. Onydaz pharmaceutical dosage form is tablet for oral administration.

Uses and Indications of Onydaz

Onydaz is primarily indicated in conditions of:

  • Mixed acute diarrhoea and dysentery
  • Lower respiratory tract infections
  • Lung abscess/emphysema
  • Bronchiectasis
  • Upper respiratory tract infections
  • Chronic sinusitis
  • Purulent sinusitis
  • Peritonsillar abscess
  • Appendicitis
  • All abscesses
  • Biliary infections
  • Osteomyelitis
  • Wound infections
  • Postoperative prophylaxis
  • Infected decubitus ulcer
  • Immunocompromised patients
  • Infections in cancer patients
  • Gynecological infections
  • Dental infections
  • Diabetic foot infections.

Posology and Method of Administration of Onydaz

One tablet of Onydaz is recommended as a twice daily therapy (i.e 12 hourly or bid) for at least 5 days or as recommended by the physician.

Contraindications of Onydaz

  • Onydaz is contraindicated in patients with known hypersensitivity to this product or any of its ingredients.
  • It is not advocated during the first trimester of pregnancy and in those with history of tendinitis or tendon rupture following use of quinolones.
  • Because of the potential for serious adverse reactions in the nursing infant, the drug must be either stopped or discontinued during lactation for at least 3 days, depending on the importance of the drug to the lactating mother.

Special warnings and precautions for use

  • Onydaz must be used with caution in those with known or suspected central nervous system (CNS) disorders such as severe cerebral arteriosclerosis, epilepsy, multiple sclerosis and other factors known or suspected which predispose to seizures.
  • In renal dysfunction, and in those hypersensitive to quinolones.
  • Must be advocated with caution in hepatic dysfunction.
  • Ofloxacin must also be avoided in those taking class non-steroidal anti-inflammatory drugs, antacids, hematinics and anticoagulants.
  • Ornidazole also has potential to interact with anticoagulants and muscle relaxants, and hence this combination must be co administered along with these agents with due caution.
  • The combination should be taken in pregnancy only if strictly necessary.
  • Ornidazole could result in abdominal cramps, flushing, nausea, vomiting, headaches and even psychotic reactions.

Onydaz Interactions with Other Medicinal Products and Other Forms of Interaction

Ofloxacin

  • Co-administered magnesium/aluminium antacids, sucralfate or iron preparations can reduce absorption. Therefore, ofloxacin should be taken 2 hours before such preparations.
  • Prolongation of bleeding time has been reported during concomitant administration of ofloxacin and anticoagulants.
  • There may be a further lowering of the cerebral seizure threshold when quinolones are given concurrently with other drugs which lower the seizure threshold, e.g. Theophylline. However ofloxacin is not thought to cause a pharmacokinetic interaction with theophylline, unlike some other fluoroquinolones. Further lowering of the cerebral seizure threshold may also occur with certain nonsteroidal anti-inflammatory drugs.
  • Ofloxacin may cause a slight increase in serum concentrations of glibenclamide administered concurrently; patients treated with this combination should be closely monitored.
  • With high doses of quinolones, impairment of excretion and an increase in serum levels may occur when co-administered with other drugs that undergo renal tubular secretion (e.g. probenecid, cimetidine, frusemide and methotrexate).

Interaction with laboratory tests

  • ┬áDetermination of opiates or porphyrins in urine may give false-positive results during treatment with ofloxacin.

Ornidazole

  • Alcohol intolerance: Unlike other nitro-imidazoles, ornidazole does not inhibit enzyme aldehyde dehydrogenase. No disulfiram like reaction has been reported on consumption of alcohol. However, as is the case with all imidazoles, this drug should be avoided in concomittance with alcohol usage
  • No clinically relevant interactions were seen with food and no interaction was found between ofloxacin and theophylline.

Onydaz Use in Pregnancy and lactation

  • No controlled studies of effect of the drug on pregnant women are available.
  • Ormidazole should be prescribed to pregnant and nursing women only if the potential benefit to the mother outweighs potential risk to the foetus/ neonate.
  • Lithium therapy: 5-nitroimidazoles (mainly metronidazole) have been found to decrease renal elimination of lithium. So, in patients undergoing concurrent lithium therapy, plasma lithium concentrations as well as creatinine and electrolyte concentrations should be monitored.Ocimix should be used with caution in conditions where the individual drugs have been used with precautionary approach.

Side Effects of Onydaz

Central Nervous System

  • Drowsiness
  • Dizziness
  • Headache
  • Tremor
  • Rigidity
  • Poor coordination
  • Epilepsy
  • Tiredness
  • Temporary loss of consciousness and fainting.

Miscellaneous

  • Nausea
  • Vomiting
  • Taste disturbances
  • Liver impairment
  • Skin reactions like rash
  • Itching and
  • Inflammation.

Overdose of Onydaz

The most important signs to be expected following acute overdosage of Onydaz are CNS symptoms such as confusion, dizziness, impairment of consciousness and convulsive seizures as well as gastrointestinal reactions such as nausea and mucosal erosions.

In the case of overdose, steps to remove any unabsorbed ofloxacin include the following: gastric lavage, administration of adsorbants and sodium sulphate, if possible during the first 30 minutes. Antacids are recommended for protection of the gastric mucosa. Elimination of ofloxacin may be increased by forced diuresis. In case of overdosage, the patient should be observed carefully and symptomatic treatment should be given. The stomach should be emptied by gastric lavage or vomiting. All the supportive measures and hydration should be maintained. In case of convulsions, intravenous diazepam is recommended.

Pharmacodynamic Properties of Onydaz

Ofloxacin

It is active after oral administration. It inhibits bacterial DNA replication by blocking DNA topo-isomerases, in particular DNA gyrase. Therapeutic doses of ofloxacin are devoid of pharmacological effects on the voluntary or autonomic nervous systems.

Ornidazole

After passive absorption into bacterium cell, the nitro group of ornidazole is reduced to amine group by ferrodoxin type redox system. The formation of redox intermediate intracellular metabolites is believed to be the key component of microorganism killing for Ornidazole. The mechanism of action is similar in protozoa.

Pharmacokinetic properties of Onydaz

Ofloxacin

Ofloxacin is almost completely absorbed after oral administration. Maximal blood levels occur 1-3 hours after dosing and elimination half-life is 4-6 hours. Ofloxacin is primarily excreted unchanged in the urine. In renal insufficiency, the dose should be reduced.

Ornidazole

Ornidazole is readily absorbed from the GIT and peak plasma concentrations of about 30 mcg/ml are achieved within 2 hours of a single dose of 1.5 g. Food does not affect extent but rate of absorption of Ornidazole. Ornidazole is less than 15% bound to plasma proteins. It is widely distributed in body tissues and fluids, including cerebrospinal fluid. Antibacterial concentrations are achieved in vaginal secretions, amniotic fluid, appendix and intestinal tissues. More than 90% of ornidazole dose is metabolized in liver. The metabolites are active and have same activity against anaerobic bacteria as the Ornidazole. The elimination half-life (11/2) of Ornidazole is 12-14 hours. It is excreted in the urine, mainly as conjugates and metabolites and to a lesser extent in the feces. Biliary excretion may be important in the elimination of Ornidazole and its metabolites.

Special Precautions for Storage

Store at a temperature below 30┬░C, protect from light, heat and moisture. Keep out of the reach of children.

References

  1. NCBI
  2. Science Alert
  3. Medicine India
  4. Zibalox drug leaflet