Generic Flagyl ( Metronidazole )

Buy Generic Flagyl (Metronidazole) without prescription in Canada

In our Canadian pharmacy, you can buy Flagyl (Metronidazole) without a prescription, with delivery across Canada within 5-14 days. Discreet and anonymous packaging.

Flagyl (metronidazole) is a nitroimidazole antibiotic and antiprotozoal agent used to treat a wide variety of infections caused by anaerobic bacteria and certain protozoa. It works by entering the microbial cell and being reduced by bacterial nitroreductases, forming reactive intermediates that damage DNA and inhibit nucleic acid synthesis, which results in cell death. It is effective against organisms such as Trichomonas vaginalis, Entamoeba histolytica, Giardia lamblia, and a broad range of anaerobic bacteria including Bacteroides, Clostridium, and Helicobacter pylori.

Usual adult dose: Dosing depends on the infection. For trichomoniasis, a single oral dose of 2 g (five 400 mg tablets) or a 7-day course of 200 mg three times daily may be used. For bacterial vaginosis, 400 mg twice daily for 7 days is typical. For amoebiasis and giardiasis, 400 mg three times daily for 5-10 days is recommended. For anaerobic bacterial infections, 400 mg three times daily for 7-14 days is common. Tablets should be swallowed whole with a full glass of water, preferably after meals to reduce stomach upset. Alcohol must be strictly avoided during treatment and for at least 48 hours after the last dose.

Dosage form: Film-coated oral tablets: 200 mg and 400 mg. In Canada, the standard marketed strengths are 250 mg and 500 mg; our pharmacy supplies internationally sourced 200 mg and 400 mg tablets through the international supply chain for personal importation. An oral suspension and injectable forms are also available.

Onset of action: Metronidazole is rapidly absorbed, with peak plasma concentrations reached within 1 to 2 hours after an oral dose. Symptomatic relief, such as reduction of vaginal discharge or abdominal pain, usually begins within 24 to 48 hours, but the full course must be completed to cure the infection.

Duration of action: The elimination half-life of metronidazole is approximately 8 hours, supporting three-times-daily dosing. Therapeutic concentrations are maintained throughout the dosing interval, and the drug continues to act for at least 24 hours after the last dose.

Alcohol recommendation: Alcohol must be completely avoided during treatment with Flagyl and for at least 48 hours after the last dose. Metronidazole can cause a severe disulfiram-like reaction when combined with alcohol, leading to intense flushing, throbbing headache, nausea, vomiting, tachycardia, and hypotension. This reaction can be dangerous and requires strict abstinence.

Most common side effects: Nausea, vomiting, diarrhoea, epigastric discomfort, metallic taste, dry mouth, headache, and dizziness. Darkening of the urine is a harmless effect of the drug. Rare but serious adverse effects include peripheral neuropathy (tingling, numbness, or pain in the hands or feet), seizures, leukopenia, and pancreatitis. Prolonged or repeated courses increase the risk of neurotoxicity.

Would you like to try Flagyl (Metronidazole) without a prescription?

General Information about Flagyl (Metronidazole)

• INN (International Nonproprietary Name): Metronidazole
• Brand names available in Canada: Flagyl® (Sanofi-Aventis Canada Inc.) is the original brand-name product. Generic metronidazole tablets are widely available in 250 mg and 500 mg strengths from manufacturers such as APO-Metronidazole (Apotex Inc.), TEVA-Metronidazole (Teva Canada Limited), Sandoz Metronidazole (Sandoz Canada Inc.), and PMS-Metronidazole (Pharmascience Inc.). The 200 mg and 400 mg strengths are not approved in Canada and are supplied internationally.
• ATC code: P01AB01 (metronidazole; nitroimidazole derivatives for amoebiasis and other protozoal diseases) and J01XD01 (for systemic antibacterial use)
• Dosage forms and strengths: Film-coated oral tablets: 200 mg and 400 mg (internationally sourced). Canadian-approved strengths: 250 mg and 500 mg. Oral suspension: 100 mg/mL. Injectable solution: 5 mg/mL.
• Manufacturers in Canada: Sanofi-Aventis Canada Inc. (Flagyl), Apotex Inc., Teva Canada Limited, Sandoz Canada Inc., Pharmascience Inc., and other generic manufacturers produce the 250 mg and 500 mg tablets. International manufacturers produce the 200 mg and 400 mg strengths.
• Registration status in Canada: Approved by Health Canada for metronidazole in the 250 mg and 500 mg tablet strengths (DINs 00203273, 00203281, and generic equivalents). The 200 mg and 400 mg tablets are not marketed in Canada and are imported for personal use under a valid prescription.
• OTC / Rx classification: Prescription only (Rx). Schedule I drug under the Controlled Drugs and Substances Act. A valid prescription from a licensed Canadian healthcare professional is required.

Mechanism of Action and Pharmacology

Metronidazole is a prodrug that requires reductive activation under anaerobic conditions. It diffuses into susceptible bacteria and protozoa, where its nitro group is reduced by low-redox-potential ferredoxin or flavodoxin. This reduction produces short-lived cytotoxic free radicals and other reactive intermediates that interact with DNA, causing strand breakage, loss of helical structure, and inhibition of nucleic acid synthesis. The result is bactericidal and protozoacidal activity. Metronidazole is active against a wide range of obligate anaerobes (Bacteroides fragilis, Clostridium difficile, Clostridium perfringens, Peptostreptococcus) and microaerophilic organisms (Helicobacter pylori), as well as the protozoal pathogens Trichomonas vaginalis, Entamoeba histolytica, and Giardia lamblia.

After oral administration, metronidazole is rapidly and almost completely absorbed, with a bioavailability exceeding 90%. Peak plasma concentrations are reached within 1 to 2 hours. Food slightly delays but does not reduce overall absorption. The drug is widely distributed in body fluids and tissues, including the central nervous system, where cerebrospinal fluid concentrations approximate serum levels. Metronidazole is metabolised in the liver primarily by oxidation and glucuronidation to several active and inactive metabolites. The elimination half-life of metronidazole is approximately 8 hours in adults with normal hepatic function. Approximately 60-80% of an oral dose is excreted in the urine, mainly as metabolites; the drug and its metabolites also appear in faeces. In patients with severe hepatic impairment, the half-life may be prolonged, and dose reduction is required. Metronidazole is removed by haemodialysis, and a supplemental dose should be administered after dialysis.

Indications

• Trichomoniasis: Treatment of urogenital infections caused by Trichomonas vaginalis in both men and women. A single 2 g dose or a 7-day course is highly effective; sexual partners should be treated simultaneously.
• Bacterial vaginosis: First-line therapy for bacterial vaginosis associated with Gardnerella vaginalis and other anaerobes. Oral metronidazole is an alternative to topical therapy.
• Amoebiasis: Treatment of intestinal amoebiasis (including amoebic dysentery) and extra-intestinal amoebiasis (including amoebic liver abscess) caused by Entamoeba histolytica.
• Giardiasis: Treatment of giardiasis caused by Giardia lamblia.
• Anaerobic bacterial infections: For the treatment of serious infections caused by susceptible anaerobic bacteria, including intra-abdominal infections, pelvic inflammatory disease, brain abscess, bacterial endocarditis, and wound infections. Often used in combination with other antibiotics for mixed aerobic-anaerobic infections.
• Helicobacter pylori eradication: As part of combination regimens for the eradication of H. pylori in peptic ulcer disease.
• Clostridioides difficile infection: First-line therapy for mild to moderate C. difficile-associated diarrhoea and colitis.
• Surgical prophylaxis: For the prevention of postoperative anaerobic infections in colorectal and gynaecological surgery.

Important Warnings and Precautions

At-risk groups

• Pregnancy: Metronidazole crosses the placenta. It should be used during pregnancy only if the potential benefit clearly outweighs the potential risk to the foetus. Short courses of metronidazole for bacterial vaginosis or trichomoniasis are generally considered safe after the first trimester. The single 2 g dose is not recommended during pregnancy. Use during the first trimester should be avoided unless no alternative is available.
• Breastfeeding: Metronidazole is excreted in human breast milk in amounts similar to maternal plasma concentrations. Because of the potential for mutagenicity and carcinogenicity (based on animal data), breastfeeding should be interrupted during treatment and for at least 24-48 hours after the last dose. A decision must be made whether to discontinue breastfeeding or to discontinue the drug.
• Paediatrics: Metronidazole is used in children for specific indications such as amoebiasis and anaerobic infections. Weight-based dosing is used (e.g., 35-50 mg/kg/day divided into three doses). Safety in neonates has not been established for all indications; the drug should be used with caution in infants under 1 month of age.
• Elderly: No specific dose adjustment is required for age alone. However, elderly patients may have decreased hepatic or renal function, and they may be more susceptible to neurological adverse effects. Monitor for peripheral neuropathy and seizures.
• Hepatic impairment: Metronidazole is metabolised in the liver. In patients with severe hepatic impairment, the elimination half-life is prolonged, and drug accumulation may occur. The dose should be reduced, or the dosing interval extended. Liver function tests should be monitored periodically.
• Renal impairment: No dose adjustment is required for patients with mild to moderate renal impairment. In end-stage renal disease on haemodialysis, a supplemental dose should be given after dialysis because metronidazole and its active metabolites are removed during the procedure. In patients with severe renal failure not on dialysis, accumulation of the neurotoxic metabolite may occur, and the drug should be used with caution.
• Neurological effects: Peripheral neuropathy (paraesthesia, pain, weakness, ataxia) and convulsive seizures have been reported, particularly with prolonged or repeated courses. Patients should be advised to report any neurological symptoms immediately. If neuropathy or seizures occur, metronidazole should be discontinued promptly and permanently.
• Disulfiram-like reaction with alcohol: Metronidazole blocks the oxidation of acetaldehyde, the same mechanism as disulfiram. Alcohol consumption during therapy or within 48 hours after the last dose can cause a severe reaction characterised by intense flushing, throbbing headache, nausea, vomiting, tachycardia, and hypotension. This reaction can be life-threatening. Patients must be strictly warned to avoid all alcoholic beverages and alcohol-containing products (e.g., certain mouthwashes, cough syrups, sauces, vinegars) during therapy and for at least 48 hours afterward.
• Blood dyscrasias: Reversible leukopenia and thrombocytopenia have been reported. Complete blood counts should be monitored during prolonged therapy (beyond 10 days). In patients with pre-existing blood disorders, metronidazole should be used with caution.
• Candidiasis: Prolonged use may result in overgrowth of non-susceptible organisms, particularly Candida species. Superinfection should be treated appropriately.
• Allergy: Do not take Flagyl if you have a known hypersensitivity to metronidazole, other nitroimidazole derivatives (e.g., tinidazole, ornidazole), or any excipient in the tablet. Cross-sensitivity may occur.

Driving and alcohol

Flagyl may cause dizziness, drowsiness, confusion, and visual disturbances. Patients should not drive, operate heavy machinery, or engage in hazardous activities until they know how the medication affects them. Alcohol must be completely avoided during treatment and for at least 48 hours after the last dose. The combination of metronidazole and alcohol can provoke a severe, potentially life-threatening disulfiram-like reaction. Patients must be counselled not to consume any alcoholic beverages, and to avoid alcohol-containing products such as mouthwashes, cough syrups, and certain food preparations.

Dosage Instructions

• Trichomoniasis: A single oral dose of 2 g (five 400 mg tablets or ten 200 mg tablets) is usually effective. Alternatively, a 7-day course of 200 mg three times daily may be used. Both sexual partners should be treated simultaneously to prevent reinfection.
• Bacterial vaginosis: 400 mg twice daily for 7 days, or 2 g as a single dose (off-label but effective). The 200 mg tablet can be used to achieve the same total daily dose.
• Amoebiasis: 400-800 mg three times daily for 5-10 days, depending on the severity and site of infection (intestinal or hepatic). A luminal amoebicide (e.g., diloxanide furoate or paromomycin) should be administered after the metronidazole course to eliminate cysts and prevent relapse.
• Giardiasis: 400 mg three times daily for 5-7 days, or 2 g once daily for 3 days.
• Anaerobic bacterial infections: 400 mg three times daily for 7-14 days, often in combination with an appropriate aerobic antibiotic for mixed infections. The dose may be increased to 800 mg three times daily for severe infections.
• Clostridioides difficile infection: 400 mg three times daily for 10-14 days for mild to moderate disease. For severe or fulminant colitis, higher doses (500 mg intravenously every 8 hours) plus oral vancomycin are typically used.
• Helicobacter pylori eradication: 400 mg twice daily for 7-14 days, in combination with a proton pump inhibitor and clarithromycin or amoxicillin.
• Surgical prophylaxis: 400 mg three times daily starting 24 hours before elective colorectal surgery, or a single 1-2 g dose 1-2 hours before surgery, combined with an antibiotic active against aerobic bacteria.
• Administration: Swallow the tablet whole with a full glass of water, preferably after meals to reduce gastrointestinal upset. Do not crush or chew. The 200 mg tablet may be easier to swallow for some patients. Complete the full prescribed course, even if symptoms improve earlier. If you miss a dose, take it as soon as remembered with food; if it is close to the time of the next dose, skip the missed dose and resume the regular schedule. Do not double the dose.

Side Effects and Contraindications

• Very common side effects (≥ 10%): Nausea, vomiting, diarrhoea, epigastric discomfort, and a metallic or bitter taste in the mouth. These are usually mild and resolve after the course is completed.
• Common side effects (1-10%): Headache, dizziness, dry mouth, dark-coloured urine (due to a metabolite, which is harmless), and furry tongue (overgrowth of Candida).
• Uncommon but serious side effects: Peripheral neuropathy (tingling, numbness, or weakness in the extremities; may be irreversible), seizures, encephalopathy, aseptic meningitis, leukopenia, thrombocytopenia, pancreatitis, and severe hypersensitivity reactions (angioedema, anaphylaxis, Stevens-Johnson syndrome). Prolonged or repeated courses increase the risk of neurotoxicity.
• Contraindications: Known hypersensitivity to metronidazole, other nitroimidazoles, or any excipient. Pregnancy (first trimester). Breastfeeding (therapy should be interrupted for the duration of treatment and 24-48 hours after). Severe hepatic impairment. Active neurological disease (e.g., epilepsy, multiple sclerosis, peripheral neuropathy). History of blood dyscrasias. Concomitant use with alcohol (during and up to 48 hours after treatment).

Drug Interactions

• Alcohol - contraindicated: Causes a severe disulfiram-like reaction. Avoid all alcohol and alcohol-containing products during therapy and for at least 48 hours after the last dose.
• Warfarin and other coumarin anticoagulants - monitor closely: Metronidazole potentiates the anticoagulant effect of warfarin, increasing the risk of bleeding. The INR should be monitored before and during therapy, and the warfarin dose adjusted as needed.
• Lithium - increased lithium toxicity: Metronidazole can increase plasma lithium concentrations, potentially leading to lithium toxicity. Lithium levels should be monitored, and the lithium dose may need to be reduced.
• Phenytoin and fosphenytoin - moderate interaction: Metronidazole may inhibit the metabolism of phenytoin, increasing its plasma concentration and the risk of phenytoin toxicity. Phenytoin levels should be monitored.
• Fluorouracil - increased toxicity: Metronidazole may reduce the clearance of fluorouracil, increasing its toxicity (bone marrow suppression, gastrointestinal toxicity). Concomitant use should be avoided or undertaken with close monitoring.
• Cimetidine - possible increased metronidazole levels: Cimetidine, a histamine H2-receptor antagonist, may inhibit the hepatic metabolism of metronidazole, potentially increasing its plasma concentration and the risk of adverse effects.
• Cyclosporine - increased cyclosporine levels: Metronidazole may increase cyclosporine serum concentrations. Renal function and cyclosporine levels should be monitored.
• Oral contraceptives: Metronidazole does not significantly reduce the efficacy of hormonal contraceptives, but some clinicians recommend additional barrier contraception during treatment as a precaution, especially if gastrointestinal side effects (vomiting) occur.
• Laboratory tests: Metronidazole may interfere with certain assays for serum hepatic enzymes (e.g., AST, ALT) if measured by spectrophotometric methods. Inform the laboratory of metronidazole use. It may also cause false-positive results for urine glucose with Benedict's or Fehling's solutions.

Practical Advice

• Administration: Take Flagyl with food or immediately after a meal to reduce stomach upset. Swallow the tablet whole with water; do not crush or chew. If you are being treated for a sexually transmitted infection (e.g., trichomoniasis), ensure that your sexual partner(s) are also treated to prevent reinfection. Complete the entire prescribed course, even if you feel better before it is finished. Strictly avoid all alcoholic beverages and alcohol-containing products during treatment and for at least 48 hours after the last dose. Read labels on mouthwashes, cough syrups, and food products.
• Monitoring: No routine laboratory monitoring is required for short-term therapy in healthy individuals. For prolonged courses (beyond 10 days), complete blood counts and liver function tests should be monitored periodically. Patients on warfarin should have their INR checked before and during therapy. Report any neurological symptoms (tingling, numbness, pain in the hands or feet, or seizures) immediately.
• Storage: Store at room temperature (15-30 °C) in a dry place, protected from moisture and light. Keep the container tightly closed and out of the reach and sight of children.
• Lifestyle: Because alcohol is strictly forbidden during treatment, plan your therapy to avoid social or occupational pressures to drink. Drink plenty of water to help clear the infection. If you are being treated for giardiasis or amoebiasis, pay careful attention to hand hygiene and avoid preparing food for others to prevent the spread of infection. If you experience severe or persistent nausea, vomiting, headache, or confusion, contact your doctor immediately.
• Missed dose: If you miss a dose, take it as soon as you remember with food. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not double the dose.
• When to seek medical review: Stop taking Flagyl and contact your doctor immediately if you develop signs of peripheral neuropathy (persistent tingling, burning, or numbness), seizures, signs of an allergic reaction (rash, hives, swelling of the face, lips, tongue, or difficulty breathing), or signs of a severe disulfiram-like reaction (flushing, throbbing headache, severe nausea/vomiting, rapid heartbeat) after accidental alcohol ingestion. If you are pregnant or become pregnant during therapy, inform your doctor.
• Disposal: Return unused or expired medication to a pharmacy for safe disposal. Do not flush down the toilet or discard in household waste.

Alternative Medications

• Tinidazole (Tindamax®): A second-generation nitroimidazole with a longer half-life, allowing for single-dose therapy for trichomoniasis, giardiasis, and bacterial vaginosis. It is approved in Canada and is often preferred due to its better tolerability and simpler dosing.
• Secnidazole (Solosec®): Another nitroimidazole with a long half-life, approved as a single-dose oral treatment for bacterial vaginosis and trichomoniasis. Not yet widely available in Canada but may be sourced internationally.
• Clindamycin (Dalacin C®): An alternative for bacterial vaginosis (oral or vaginal cream) and anaerobic infections. It is not effective against protozoa.
• Paromomycin (Humatin®): A non-absorbed aminoglycoside used for intestinal amoebiasis and giardiasis, particularly during pregnancy, because it lacks systemic toxicity.
• Nitazoxanide (Alinia®): An antiprotozoal agent for giardiasis and cryptosporidiosis, used when nitroimidazoles are not tolerated or are contraindicated.
• Vancomycin (oral): First-line therapy for severe Clostridioides difficile infection, used when metronidazole is ineffective or contraindicated.
• Non-pharmacological measures: For gastrointestinal protozoal infections, meticulous hand hygiene, proper food and water sanitation, and avoidance of contaminated sources are essential to prevent infection and reinfection. For sexually transmitted infections, partner notification and treatment are critical.

Clinical Efficacy

Metronidazole has been a cornerstone of therapy for anaerobic and protozoal infections for over five decades. For trichomoniasis, a single 2 g oral dose achieves parasitological cure rates of over 95%, comparable to a 7-day course. In bacterial vaginosis, oral metronidazole 400 mg twice daily for 7 days resolves symptoms and normalises vaginal flora in approximately 80-90% of women. For amoebiasis, metronidazole 400-800 mg three times daily for 5-10 days is highly effective, with clinical and parasitological cure rates of 90-95%. For giardiasis, metronidazole 400 mg three times daily for 5 days achieves cure rates exceeding 90%. In anaerobic infections, metronidazole used in combination with an appropriate aerobic antibiotic produces clinical success rates of 85-95%. For Clostridioides difficile infection, metronidazole 400 mg three times daily is effective in mild to moderate cases. The drug's efficacy, low cost, and wide availability make it an essential medicine globally. However, its use is associated with notable side effects, particularly neurological toxicity with prolonged therapy, and the mandatory alcohol restriction requires careful patient counselling. In Canada, metronidazole remains a first-line agent for many of its indications, and our pharmacy provides the internationally sourced 200 mg and 400 mg tablets to meet individual patient needs.

Important:

Flagyl (metronidazole) is a prescription antibiotic and antiprotozoal agent that must be used under the supervision of a qualified healthcare professional. Alcohol must be completely avoided during treatment and for at least 48 hours after the last dose. Consuming alcohol while taking this medication can cause a severe, potentially life-threatening disulfiram-like reaction. Neurological side effects, including peripheral neuropathy and seizures, have been reported, especially with prolonged or repeated courses. If you experience tingling, numbness, pain in the hands or feet, or convulsions, discontinue the medication and seek immediate medical attention. This drug should not be used during the first trimester of pregnancy or while breastfeeding without consulting your physician. The 200 mg and 400 mg tablets are not approved for marketing in Canada and are imported for personal use under a valid prescription. If you have liver disease, a history of seizures, or blood disorders, inform your doctor before starting therapy. This information is not a substitute for professional medical advice, diagnosis, or treatment.

Get Generic Flagyl - Shipping across Canada