Flagyl ER (Metronidazole) Extended-Release Tablets

We stock Flagyl ER, the extended-release oral tablet form of metronidazole, in two strengths and several package sizes, so Canadian customers can match the exact product to a prescribed course rather than settling for a one-size package. This guide walks through what we currently offer, how the package sizes compare in value, and the practical details that matter once a customer has decided which option to order.

Flagyl ER tablets are taken by mouth and are designed to release metronidazole over an extended period, which is a meaningfully different presentation from standard immediate-release metronidazole tablets. We keep that extended-release identity consistent across every strength and package we list, so customers comparing options with us are always comparing like with like.

Flagyl ER: The Real Choices We Offer

When customers order Flagyl ER from us, they are choosing across three variables: strength, package quantity, and total pills needed for a planned course. We offer 200 mg and 400 mg extended-release tablets. The 400 mg strength is available in packages of 90, 120, 180, 270, and 360 pills, while the 200 mg strength is available in packages of 120, 180, 270, and 360 pills. Each package is priced in Canadian dollars, and the per-pill unit value changes as the package size changes, which is worth understanding before placing an order.

Available Packages and Unit Value

Because Flagyl ER is usually taken as part of a defined treatment course rather than as an ongoing daily medicine, the package size someone chooses should reflect the course length and total dose a prescriber has set out, not simply the lowest price per pill. We show exact package quantities, prices, and unit values for the 400 mg strength below so customers can compare options directly.

As the comparison shows, larger packages may carry a lower price per pill. However, a larger package is appropriate only when its quantity corresponds to the current treatment plan. Customers should weigh unit value against the prescribed course, storage requirements, and expiry date rather than ordering extra pills solely because the unit price is lower. Metronidazole should not be saved for a future illness or used for another course unless a prescriber specifically directs it.

How Do I Choose Between 200 mg and 400 mg, and What Quantity Makes Sense?

The right strength and quantity for any individual depend on what a prescriber has specified, since metronidazole dosing is set according to the infection being treated, patient-specific factors, and treatment duration. We do not set that regimen for a customer; we make sure the strength and package size ordered match the intended treatment plan.

To help customers think through the options we carry, the table below summarizes which package quantities are currently available at each strength.

A few practical points follow from this layout. First, the 400 mg strength includes a 90-pill option that is not available for the 200 mg strength, giving customers an additional lower-quantity choice. Second, both strengths are offered in quantities up to 360 pills, so a prescribed total that warrants a larger quantity may be covered without combining several smaller packages. Third, customers should not combine or substitute strengths unless their prescriber has instructed them to do so. Both strengths use the same extended-release form, but they deliver different amounts of metronidazole.

Flagyl ER Compared With Generic Metronidazole and Other Options

Flagyl ER is the extended-release brand presentation of metronidazole. Standard immediate-release metronidazole tablets are often taken on different schedules and are not the product we are describing here; we mention this so customers searching for metronidazole in general understand that Flagyl ER specifically refers to the extended-release tablet we carry in 200 mg and 400 mg strengths.

Other nitroimidazoles and antibiotics with activity against anaerobic organisms include tinidazole, secnidazole, and clindamycin, each with its own dosing schedule, spectrum, and side-effect profile. Vancomycin and fidaxomicin serve a narrower role, mainly for Clostridioides difficile infection, and are not interchangeable with Flagyl ER for most indications. A prescriber chooses between these options based on the infection being treated; our role is to supply the exact product, strength, and quantity that has been decided on. Customers wanting to browse related antimicrobial options can also visit our Antibiotics category.

What Flagyl ER Is Used For

Metronidazole is a nitroimidazole antibiotic and antiprotozoal agent. Extended-release oral metronidazole is established for adult use, including the treatment of bacterial vaginosis. Metronidazole also has a broader role against susceptible anaerobic bacterial and certain protozoal infections, although the appropriate formulation, strength, and regimen depend on the condition. Customers interested in bacterial vaginosis treatment and related concerns may also find our Women's Health category useful for browsing related products.

• Bacterial vaginosis in adult women
• Susceptible anaerobic bacterial infections when an oral extended-release regimen is appropriate
• Certain protozoal infections, as directed by a prescriber

A prescriber determines whether Flagyl ER is appropriate for a given infection, and the extended-release tablet is not interchangeable with immediate-release, topical, or vaginal metronidazole products, which are different formulations.

How Does Flagyl ER Work, and How Should It Be Taken?

Metronidazole is converted within susceptible anaerobic bacteria and certain protozoa into reactive compounds that damage DNA and inhibit nucleic acid synthesis, leading to cell death. The extended-release formulation releases the active ingredient gradually after swallowing and supports the dosing schedule specified for that formulation and condition.

General administration guidance is to take Flagyl ER on an empty stomach, at least one hour before or two hours after a meal, because food may alter absorption from the extended-release formulation. A prescriber's specific instructions should always take priority. Tablets are swallowed whole; they are not split, crushed, or chewed, because doing so can interfere with extended release. Treatment duration varies with the condition and prescribed regimen. Improvement may begin within a few days, but the full course should be completed even if symptoms ease earlier.

Safety Considerations and Interactions to Keep in Mind

Flagyl ER carries the core safety considerations associated with oral metronidazole. Common effects reported with metronidazole use include:

• Nausea, a metallic taste, or loss of appetite
• Headache or dizziness
• Dry mouth or a furred tongue
• Darkened urine, which is a known and generally harmless effect

Alcohol should be avoided during treatment and for at least three days after the last dose because the combination may cause flushing, nausea, vomiting, abdominal cramps, or a fast heartbeat. Metronidazole also interacts with certain medicines, including warfarin and related anticoagulants, lithium, disulfiram, and some seizure medicines, so a complete medication list should be shared with the prescriber before starting Flagyl ER.

• Known hypersensitivity to metronidazole, other nitroimidazole derivatives, or formulation ingredients is a contraindication.
• Pregnancy requires an individual benefit-risk discussion with a prescriber because metronidazole crosses the placenta.
• Metronidazole passes into human milk. A prescriber should help decide whether to interrupt breastfeeding or use another treatment, taking the importance and duration of therapy into account.
• Safety and effectiveness in children have not been established for the extended-release tablet.

Because metronidazole can cause dizziness, confusion, visual disturbances, or other neurological effects, driving or operating machinery should be avoided until a person knows how the medicine affects them. New numbness or tingling, poor coordination, seizures, severe confusion, or signs of a serious allergic or skin reaction require prompt medical attention. Anyone using Flagyl ER should keep their prescriber informed of other health conditions and medicines and seek advice if side effects persist or worsen.

Do I Need a Prescription to Order Flagyl ER From Us in Canada?

Metronidazole is authorised for human use in Canada, and extended-release metronidazole tablets are classified as a prescription dosage form under Canadian drug regulation. That classification describes the product itself, separate from how we process an order. Our ordering policy does not require a prescription to be submitted before we accept an order for Flagyl ER, so customers can place an order with us without prescription paperwork at checkout. This describes our ordering process rather than changing the medicine's underlying prescription status, and customers who have been prescribed Flagyl ER should still follow their prescriber's instructions on strength, quantity, and course length.

Ordering, Packing, and Delivery With Us

We have operated our online catalogue since 2017, and our support team, including a pharmacist, is available 24/7 through email, online chat, and phone for questions about an order before or after it is placed.

• Select the strength, 200 mg or 400 mg, and the package quantity that matches the intended course.
• Complete checkout in Canadian dollars using our accepted payment options.
• We pack Flagyl ER to protect it from light and excess heat or moisture in transit, in keeping with its storage needs.
• Delivery is arranged to addresses across Canada, with tracking details provided after dispatch.

Once an order arrives, tablets should be stored at 20°C to 25°C in a tightly closed, light-resistant container, away from direct light, moisture, and heat, and kept out of reach of children. Checking the expiry date on arrival and before taking tablets from the supplied package helps ensure they remain within their usable life.

Making the Best-Value Decision for Your Supply

Choosing the right Flagyl ER package comes down to matching the strength and quantity we offer to the course a prescriber has set, then using the unit-value comparison to avoid overpaying for that quantity. A larger package can offer better per-pill value, but only when the extra pills correspond to a genuine treatment need rather than simply the appeal of a lower unit price. The practical approach is to confirm the prescribed strength and total quantity first, review the package-value comparison for that strength, and then select the closest available package that covers the intended course without an unnecessary surplus.