Metronidazole + Ofloxacin

Usage

Metronidazole + Ofloxacin is a combination antibiotic used to treat various bacterial and parasitic infections, including:

• Bacterial infections of the respiratory tract, skin, soft tissues, bones, joints, and abdomen.
• Parasitic infections such as amebiasis (including liver abscess), giardiasis, and trichomoniasis.
• Pelvic inflammatory disease (PID).
• Bacterial vaginosis.

Pharmacological Classification: Antibiotic (a combination of a fluoroquinolone and a nitroimidazole).

Alternate Names

No widely recognized alternate names exist for this specific combination. Brand names may vary depending on the manufacturer and region. Some brand names include Ofet-M, Metrogyl Plus.

How It Works

Pharmacodynamics:

• Ofloxacin: Inhibits bacterial DNA gyrase and topoisomerase IV, enzymes crucial for bacterial DNA replication and repair. This inhibition prevents bacterial cell division and leads to cell death.

• Metronidazole: Disrupts DNA synthesis and causes DNA strand breakage in susceptible anaerobic bacteria and protozoa, leading to cell death.

Pharmacokinetics:

• Both drugs are well-absorbed orally. Ofloxacin can also be administered intravenously.
• Metabolized in the liver (primarily ofloxacin) and excreted in the urine and feces.
• Elimination half-life varies depending on the specific drug and patient factors.

Dosage

Standard Dosage

Adults: Ofloxacin 200-400 mg twice daily plus metronidazole 400mg twice a day, for 7-14 days. The dose and duration may vary depending on the infection being treated.

Children: Not generally recommended for use in children due to the risk of adverse effects on developing cartilage. In certain circumstances, it might be prescribed by a pediatrician in appropriate doses, generally based on weight.

Special Cases:

• Elderly Patients: Dose adjustment may be required due to decreased renal function.

• Patients with Renal Impairment: Dose reduction may be needed depending on creatinine clearance.

• Patients with Hepatic Dysfunction: Caution is advised. Dose adjustment may be necessary.

• Patients with Comorbid Conditions: Consider individual patient factors.

Clinical Use Cases

The dosage in specific clinical situations, such as intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations, would be determined by the treating physician based on the patient’s specific needs and the infection being treated. There is no fixed dosage in these scenarios.

Dosage Adjustments

Dosage adjustments are based on patient factors like renal/hepatic dysfunction, and other comorbid conditions, and should be made as deemed necessary by the physician.

Side Effects

Common Side Effects:

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Headache
• Dizziness

Rare but Serious Side Effects:

• Peripheral neuropathy
• Seizures
• Tendon rupture
• Clostridium difficile-associated diarrhea
• QT prolongation
• Hepatotoxicity
• Stevens-Johnson syndrome

Long-Term Effects:

Peripheral neuropathy can be a long-term effect with prolonged metronidazole use.

Contraindications

• Hypersensitivity to ofloxacin, metronidazole, or other quinolones/nitroimidazoles.
• Epilepsy or other seizure disorders.
• History of tendon disorders related to fluoroquinolone use.
• Pregnancy (especially first trimester).
• Breastfeeding (short courses are generally considered compatible).
• Patients with myasthenia gravis

Drug Interactions

• Antacids, multivitamins containing metals (calcium, magnesium, aluminum, iron, zinc) – can decrease absorption of ofloxacin.
• Warfarin and other anticoagulants – ofloxacin can enhance anticoagulant effects.
• Theophylline – ofloxacin can increase serum theophylline levels.
• Nonsteroidal anti-inflammatory drugs (NSAIDs) - increased risk of CNS stimulation.
• Alcohol – disulfiram-like reaction with metronidazole (nausea, vomiting, flushing, headache).

Pregnancy and Breastfeeding

• Pregnancy: Contraindicated, especially during the first trimester.

• Breastfeeding: Short courses of metronidazole are generally considered safe. Ofloxacin is excreted in breast milk, and its use during lactation is not recommended unless the benefits outweigh the risks.

Drug Profile Summary

• Mechanism of Action: Ofloxacin inhibits bacterial DNA gyrase. Metronidazole disrupts DNA in anaerobic bacteria and protozoa.

• Side Effects: Nausea, vomiting, diarrhea, headache, dizziness (common). Seizures, peripheral neuropathy, tendon rupture, C. difficile infection, QT prolongation, hepatotoxicity (rare but serious).

• Contraindications: Hypersensitivity, epilepsy, history of tendon disorders with quinolones, pregnancy, breastfeeding (for extended use), myasthenia gravis.

• Drug Interactions: Antacids, warfarin, theophylline, NSAIDs, alcohol.

• Pregnancy & Breastfeeding: Contraindicated in pregnancy. Short courses of metronidazole are generally considered safe during breastfeeding. Avoid prolonged ofloxacin use.

• Dosage: Adults: Ofloxacin 200-400 mg twice daily + metronidazole 400 mg twice daily. Pediatric use is restricted.

• Monitoring Parameters: Renal function, liver function tests, signs of peripheral neuropathy, tendon inflammation, cardiac rhythm for QT prolongation.

Popular Combinations

This medication itself is a combination, so combining it with other medications is not recommended unless prescribed and warranted for a specific clinical situation under supervision.

Precautions

• Patients should be monitored for signs of peripheral neuropathy and tendonitis.
• Avoid alcohol during and shortly after metronidazole treatment.
• Caution in patients with liver or kidney disease.
• May impair mental alertness; caution with driving or operating machinery.
• Photosensitivity may occur; advise patients to avoid excessive sun exposure.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Metronidazole + Ofloxacin?

A: The standard adult dose is Ofloxacin 200-400mg twice daily plus Metronidazole 400mg twice daily for 7-14 days. Dosage adjustments may be needed in elderly patients and those with hepatic/renal insufficiency.

Q2: Can this combination be used in children?

A: It is generally avoided in children due to potential adverse effects on developing cartilage. In certain cases, a pediatrician might prescribe it cautiously.

Q3: What are the most common side effects?

A: Nausea, vomiting, diarrhea, headache, and dizziness are common side effects.

Q4: Are there any serious side effects I should be aware of?

A: Although rare, serious side effects include seizures, peripheral neuropathy, tendon rupture, C. difficile infection, QT prolongation, and liver toxicity.

Q5: What are the contraindications for this combination?

A: Contraindications include hypersensitivity, epilepsy, prior tendon disorders with quinolones, pregnancy, and myasthenia gravis. Breastfeeding should be avoided with prolonged use.

Q6: Can I drink alcohol while taking Metronidazole + Ofloxacin?

A: No, alcohol should be strictly avoided as it can cause a disulfiram-like reaction with metronidazole.

Q7: What should I do if I miss a dose?

A: Take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not double the dose.

Q8: Can I stop taking the medication once I feel better?

A: No, completing the full course of antibiotics as prescribed, even if you feel better, is crucial to prevent recurrence and the development of antibiotic resistance.

Q9: What are the drug interactions with Metronidazole + Ofloxacin?

A: Avoid concomitant use with antacids, metal-containing supplements, warfarin, theophylline, NSAIDS, and alcohol, as they can lead to interactions.

Q10: How is Metronidazole + Ofloxacin eliminated from the body?

A: Metronidazole is primarily metabolized in the liver, and its metabolites are excreted in the urine. Ofloxacin is partially metabolized and eliminated primarily through renal excretion.