Flagyl ER (metronidazole extended-release) is a prescription antibiotic and antiprotozoal medication designed to provide sustained, effective treatment for a range of anaerobic bacterial and certain parasitic infections. Its advanced extended-release formulation ensures consistent therapeutic levels, enhancing patient compliance and treatment success. This medication is specifically engineered to target infections at their source while minimizing dosing frequency.

Features

• Extended-release tablet formulation for once-daily dosing
• Active ingredient: metronidazole (750 mg per tablet)
• Designed for gradual drug release over 24 hours
• Bioequivalent to immediate-release metronidazole formulations
• Available in 30-count prescription bottles
• Film-coated for easier swallowing

Benefits

• Maintains consistent therapeutic drug levels throughout the treatment period
• Reduces dosing frequency from multiple times daily to once daily
• Improves patient adherence to treatment regimens
• Provides effective eradication of susceptible anaerobic microorganisms
• Minimizes peak-trough fluctuations in plasma concentrations
• Offers convenient dosing for complete therapeutic courses

Common use

Flagyl ER is primarily indicated for the treatment of bacterial vaginosis in adult women. It is also used off-label for other anaerobic bacterial infections including intra-abdominal infections, skin and skin structure infections, gynecological infections, bone and joint infections, CNS infections, and lower respiratory tract infections caused by susceptible anaerobic bacteria. Additionally, it may be prescribed for certain parasitic infections including amebiasis and trichomoniasis when extended-release formulation is appropriate.

Dosage and direction

The recommended dosage for bacterial vaginosis is one 750 mg tablet taken orally once daily for 7 consecutive days. Tablets should be swallowed whole with a full glass of water, without chewing, crushing, or splitting. Administration with food may help minimize gastrointestinal discomfort. For other infections, dosing may vary based on infection severity, patient weight, and renal function. Complete the full prescribed course even if symptoms improve earlier to prevent antibiotic resistance.

Precautions

Avoid alcohol consumption during treatment and for at least 3 days after completing therapy due to the potential for disulfiram-like reaction (nausea, vomiting, flushing, tachycardia). Use with caution in patients with blood dyscrasias, hepatic impairment, or CNS disorders. May cause dizziness or drowsiness; exercise caution when operating machinery or driving. Regular monitoring of blood counts is recommended during prolonged therapy. Not recommended during pregnancy unless clearly needed, particularly during the first trimester.

Contraindications

Hypersensitivity to metronidazole, nitroimidazole derivatives, or any component of the formulation. Contraindicated in patients with trichomoniasis during the first trimester of pregnancy. Avoid use in patients with active organic neurologic disease. Not recommended for patients with severe hepatic impairment (Child-Pugh C). Contraindicated in patients taking disulfiram or who have taken disulfiram within the past 2 weeks.

Possible side effect

Common side effects include nausea (≈10%), headache (≈9%), metallic taste (≈8%), and anorexia (≈5%). Less frequently reported effects include vomiting, diarrhea, abdominal discomfort, dizziness, and dry mouth. Rare but serious side effects may include peripheral neuropathy, seizures, encephalopathy, leukopenia, pancreatitis, and hypersensitivity reactions. Darkening of urine may occur but is harmless. Report any persistent or severe side effects to your healthcare provider immediately.

Drug interaction

Significant interactions occur with warfarin (potentiates anticoagulant effect), lithium (increased lithium levels), disulfiram (psychotic reactions), and alcohol (disulfiram-like reaction). May increase levels of phenytoin, phenobarbital, and cyclosporine. Cimetidine may increase metronidazole levels. Concurrent use with busulfan may increase busulfan toxicity. Cholestyramine may decrease metronidazole absorption.

Missed dose

If a dose is missed, take it as soon as remembered unless it is almost time for the next scheduled dose. Do not double the dose to make up for a missed one. Maintain regular dosing intervals to ensure consistent therapeutic levels. If multiple doses are missed, contact your healthcare provider for guidance on resuming therapy.

Overdose

Symptoms may include nausea, vomiting, ataxia, seizures, and peripheral neuropathy. There is no specific antidote for metronidazole overdose. Treatment is supportive and symptomatic, including gastric lavage if presented early. Hemodialysis may accelerate elimination. Management should include monitoring of neurological status and supportive care for any presenting symptoms.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) in the original container. Protect from light and moisture. Keep tightly closed and out of reach of children. Do not use after the expiration date printed on the packaging. Do not transfer to other containers as this may affect stability.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting, changing, or stopping any medication. The prescribing physician should be aware of the patient’s complete medical history and current medications. Individual response to medication may vary.

Reviews

“Flagyl ER provided effective treatment for my recurrent bacterial vaginosis with much better convenience than the multiple daily dosing I previously experienced. The once-daily regimen made compliance significantly easier.” - Verified Patient

“As a healthcare provider, I find the extended-release formulation particularly valuable for patients who struggle with multiple daily dosing schedules. The therapeutic outcomes have been comparable to immediate-release formulations with improved adherence rates.” - Medical Professional