Flagyl ER (Metronidazole) Extended-Release Tablets: Prices and Package Options

Flagyl ER is an oral extended-release tablet containing metronidazole, a nitroimidazole antibiotic. The extended-release design controls how the medicine is released after a tablet is swallowed, but the appropriate dose, schedule, and course length still depend on the infection and the directions provided by a prescriber. We carry Flagyl ER in two strengths, 200 mg and 400 mg, with several package quantities available for each strength.

This guide walks through the packages, the unit value behind each one, and the practical, safety, and Canadian ordering details that should inform your choice, without replacing the dosing instructions on your prescription, dispensing label, or package insert.

Price and choice overview

We price Flagyl ER in Canadian dollars by strength and package size. Every option contains metronidazole in an oral extended-release tablet, while the strength per tablet and the number of pills in the package vary. Comparing those details side by side is the most useful first step before you open checkout.

Antibiotic treatment is commonly prescribed as a defined course. The right option is therefore the strength specified for your regimen and a quantity that fits the medically directed plan, not automatically the package with the lowest price per pill. The 200 mg and 400 mg tablets should not be substituted for one another or combined to recreate a dose unless a prescriber or pharmacist has specifically confirmed that approach.

Available packages and unit value

We offer Flagyl ER 200 mg in packages of 120, 180, 270, and 360 pills. Flagyl ER 400 mg is available in packages of 90, 120, 180, 270, and 360 pills. These are catalogue quantities rather than representations of standard course lengths; the number needed for any particular treatment depends on the prescribed regimen.

The comparison below covers all five package quantities currently available from us for Flagyl ER 400 mg. It shows total price and price per unit in Canadian dollars so that customers who have already been directed to use the 400 mg strength can compare package value without relying on external price claims.

Unit value may improve as package size grows, but a larger package is only genuinely useful when it matches a medically appropriate planned supply that can be used before the printed expiry date. Customers selecting 200 mg should confirm the total price for their chosen package at checkout, as the comparison above is specifically for 400 mg.

Before choosing a package, it helps to check:

• the exact strength named in your treatment instructions;
• the prescribed number of tablets per dose and the dosing frequency;
• the full duration of treatment and resulting quantity required;
• whether you already have any usable supply on hand; and
• the storage conditions and expiry date once the order arrives.

How do we decide between the 200 mg and 400 mg tablets, and how many pills to order?

The strength identifies how much metronidazole each extended-release tablet contains. It does not, by itself, establish how many tablets should be taken or how often they should be used. Metronidazole regimens vary by the organism, infection site, clinical circumstances, kidney or liver considerations, and the formulation selected by the prescriber.

The table below sets out the package quantities we currently offer for each strength, independent of price. Use it to confirm that the strength and pill count match your documented treatment plan before comparing value.

If your prescriber has specified a strength, start there and calculate the required quantity only from the complete directions provided. Do not assume that two 200 mg extended-release tablets can replace one 400 mg tablet, or that a larger package is suitable for future self-treatment. Any unused antibiotic should be handled according to local pharmacy disposal advice rather than saved for an unidentified future infection.

Flagyl ER, immediate-release metronidazole, and other antibiotics

Flagyl ER is a branded extended-release presentation of metronidazole. Immediate-release metronidazole contains the same active ingredient, but its release characteristics and dosing schedule differ. The formulations are not interchangeable tablet for tablet, and extended-release tablets should not be replaced with another formulation without professional direction.

Tinidazole and secnidazole are related nitroimidazoles, while clindamycin is from a different antibiotic class. These medicines can have overlapping uses in selected infections, but their dosing, contraindications, interactions, and adverse-effect profiles differ. A switch is a clinical decision, not a simple brand or price substitution.

For background on a penicillin-class antibiotic used for different susceptible infections, see Augmentin. It is not a direct substitute for Flagyl ER. You can also browse our Antibiotics section for general product navigation.

Established use and the role of this product

Metronidazole is an established anti-infective active against susceptible anaerobic bacteria and certain protozoa. Extended-release metronidazole has an established adult role in treating bacterial vaginosis, while metronidazole more broadly is used for selected anaerobic and protozoal infections. The precise formulation and regimen must be matched to the diagnosed condition.

Metronidazole does not treat viral infections, and it is not suitable for most fungal infections. Symptoms alone do not reliably identify a susceptible bacterial or protozoal infection, so Flagyl ER should not be used for an undiagnosed illness or leftover treatment from an earlier episode. Readers looking for broader information related to bacterial vaginosis can visit our Woman's Health section.

How it works and how to take it

Inside susceptible anaerobic organisms, metronidazole is converted into reactive compounds that disrupt DNA and other cellular processes. The extended-release design controls how quickly the medicine is released, which is why the tablets should be swallowed whole rather than split, crushed, or chewed.

Follow the exact directions on the prescription or dispensing label. Flagyl ER is generally directed to be taken on an empty stomach, about one hour before or two hours after a meal, but the prescribed schedule remains controlling. Take each dose with water and complete the directed course even if symptoms improve, unless a clinician tells you to stop.

If you miss a dose, follow the instructions supplied with the medicine or ask a pharmacist. In general, a missed dose should not be replaced by taking two doses together unless specifically directed. Contact a healthcare professional if vomiting, severe diarrhoea, or difficulty swallowing prevents you from taking the tablets as instructed.

Avoid alcoholic drinks and products containing alcohol or propylene glycol during treatment and for at least three days after the last dose. Combining them with metronidazole may cause nausea, vomiting, abdominal cramps, headache, flushing, or a rapid heartbeat.

Important safety and interaction points

Common effects reported with metronidazole include a metallic taste, nausea, headache, abdominal discomfort, and dizziness. Dark or reddish-brown urine can also occur and is usually a harmless effect of metronidazole. Seek medical advice if an effect is severe, persistent, or accompanied by other concerning symptoms.

Less common but more serious effects include tingling or numbness that may indicate peripheral neuropathy, unsteadiness, confusion, seizures, severe skin reactions, or signs of liver injury such as yellowing of the skin or eyes. These require prompt medical assessment. Longer treatment or repeated courses may call for clinical review and, where appropriate, blood counts or other monitoring.

• Do not use metronidazole if you have a known hypersensitivity to metronidazole, another nitroimidazole, or an ingredient in the tablet.
• Tell your prescriber about warfarin or other anticoagulants, lithium, phenytoin, phenobarbital, busulfan, fluorouracil, ciclosporin, or disulfiram. Metronidazole should generally not be used with disulfiram or within two weeks after disulfiram treatment.
• Discuss significant liver disease, a history of blood disorders, or neurological conditions before treatment, as these may affect dosing or monitoring.
• Pregnancy requires an individual assessment of expected benefit and potential risk.
• Metronidazole passes into human milk. A prescriber should help decide whether to pause breastfeeding or use a different treatment, taking the dose, treatment duration, and importance of breastfeeding into account.
• Avoid driving or operating machinery until you know how the medicine affects you, as dizziness, confusion, visual disturbances, or other neurological effects are possible.

Safety and effectiveness of extended-release metronidazole tablets have not been established in children. The product is intended for adult use unless a qualified prescriber provides patient-specific directions.

What Canadian customers should know about access and prescriptions

Metronidazole is authorised for human medicinal use in Canada, and oral extended-release metronidazole tablets are prescription medicines. That regulatory classification concerns the dosage form itself and is separate from our ordering policy. We do not require customers to submit a prescription for us to accept an order for this product.

Not requiring a prescription at checkout does not make Flagyl ER a non-prescription medicine or remove the need for an appropriate diagnosis and medically directed regimen. If you have questions about the product or an order, our pharmacist-supported team is available by email and online chat 24 hours a day, seven days a week.

Ordering, delivery, and receiving your order

Once you have matched a strength and package quantity to your treatment instructions, our checkout confirms the exact option selected, including strength, pill count, and price in Canadian dollars. We have supported Canadian customers since 2018. Our team packs and dispatches orders for delivery to addresses across Canada, with support available for questions about an order already placed or one you are still considering.

When the order arrives, check that the label shows Flagyl ER, metronidazole, the expected 200 mg or 400 mg strength, and the correct pill count. Do not use the medicine if the package appears damaged, the label does not match the order, or the tablets show unexpected deterioration; contact our support team for help.

Store the tablets between 20°C and 25°C in a tightly closed, light-resistant container and protect them from light. Keep them out of reach of children and do not transfer them to an unlabelled container. Correct storage helps protect product quality through the printed expiry date.

Making the value-based decision

• Match the 200 mg or 400 mg strength to the documented treatment directions rather than choosing by price alone.
• Use the 400 mg package comparison to see how total price and price per pill change across the five available quantities.
• For 200 mg, choose from 120, 180, 270, or 360 pills and confirm the applicable total at checkout.
• Select a quantity based on the complete prescribed regimen, without saving extra antibiotic for self-treatment.
• Keep the tablets in the recommended container and storage conditions until they are used or properly disposed of.
• Contact our pharmacist-supported team by chat or email if you need product or package information before ordering.

A lower price per pill can contribute to good value, but only when the selected strength and quantity align with an appropriate treatment plan. The most economical option is not automatically the most suitable one; identity, prescribed use, expected quantity, safe storage, and timely use all matter.