Metronidazole (Flagyl)
Metronidazole, commonly known as Flagyl Generic, is a powerful antibiotic and antiprotozoal medication used to combat infections caused by anaerobic bacteria and certain parasites. The active substance in this medication is metronidazole, which works by disrupting the DNA of these microorganisms, effectively stopping their growth and replication. It’s often prescribed for conditions like bacterial vaginosis (BV), trichomoniasis, giardiasis, amoebic dysentery, and various other infections where anaerobic bacteria play a significant role.
Think of it as a targeted strike against unwelcome guests in your body – metronidazole doesn’t harm the good bacteria, but efficiently eliminates those causing trouble. While specific manufacturers can vary, Sigma Pharmaceuticals is a known supplier, with information accessible as recently as 2021. It’s important to remember that this medication requires a prescription and should only be taken under the guidance of a healthcare professional.
Metronidazole isn’t a one-size-fits-all solution; it’s tailored to your specific infection and health profile. The effectiveness of metronidazole is well documented, with cure rates for bacterial vaginosis ranging from 70% to 80%, making it a reliable option when prescribed appropriately. However, like any medication, understanding its nuances is key to safe and effective use.
Forms & Dosages Available
Metronidazole comes in several forms to suit different needs and treatment plans. The most common form is the tablet, available in strengths of 400mg and 500mg. These tablets are typically film-coated for easier swallowing and can be taken whole with water, ideally with a meal. Dr Fox commonly supplies 14 x 400mg tablets for a 7-day course of treatment.
Beyond tablets, metronidazole is also available as a 0.75% vaginal gel (Zidoval) for treating bacterial vaginosis directly in the affected area. This offers a convenient alternative to oral medication. While less common, intravenous formulations are used in hospitals for severe infections requiring immediate and potent action. It’s crucial to follow your doctor’s instructions regarding dosage and duration of treatment precisely.
Regarding tablet splitting, it is generally not recommended unless specifically instructed by your doctor or pharmacist. The coating on the tablets helps with controlled release, and breaking them can alter this process. Here’s a quick overview in table format:
| Form | Strength | Administration | Splittable? |
|---|---|---|---|
| Tablets | 400mg/500mg | Oral, with water, ideally with food | No |
| Vaginal Gel | 0.75% | Intravaginal application | N/A |
| Injection | Varies | Intravenous (administered by a healthcare professional) | N/A |
Who Can Take Metronidazole?
Metronidazole is generally suitable for both men and women, though it’s frequently prescribed to women for bacterial vaginosis and trichomoniasis. Age isn’t typically a strict barrier, but dosage adjustments may be necessary for individuals with kidney problems or those undergoing dialysis – specialist advice is crucial in these cases.
However, certain populations require extra caution. It’s generally not recommended during pregnancy, particularly the single high dose of 2 grams, as some studies have linked its use to an increased risk of miscarriage (though this may be due to the underlying infection itself). Dr Fox does not prescribe for pregnant women; consultation with a GP or midwife is essential.
Similarly, breastfeeding mothers should avoid metronidazole as it passes into breast milk and can affect its taste. The elderly might also require lower doses due to potential kidney function decline. Always inform your doctor about any pre-existing medical conditions and all medications you are taking before starting metronidazole.
How To Take Metronidazole Generic
Taking metronidazole correctly is vital for maximizing its effectiveness and minimizing side effects. Generally, tablets should be swallowed whole with water, ideally during or immediately after a meal to reduce potential stomach upset. For bacterial vaginosis, Dr Fox typically prescribes 14 x 400mg tablets taken twice daily (every 12 hours) for seven days.
Timing is key; maintaining consistent intervals between doses ensures optimal drug levels in your system. Metronidazole has a half-life of approximately 8 hours, meaning it takes that long for the concentration in your body to reduce by half. Therefore, spacing doses roughly 12 hours apart helps maintain therapeutic levels. If you miss a dose, take it as soon as you remember unless it’s almost time for your next scheduled dose – do not double up to catch up.
Crucially, avoid alcohol consumption both during treatment and for at least 48 hours after finishing the course. Combining metronidazole with alcohol can cause a disulfiram-like reaction, resulting in unpleasant symptoms like nausea, vomiting, dizziness, and chest pain. It’s also important to complete the full course of treatment even if you start feeling better before it’s finished – stopping early could lead to incomplete eradication of the infection.
How Does Metronidazole Work?
Metronidazole works by targeting the very core of anaerobic bacteria and certain parasites: their DNA. These microorganisms lack the mechanisms to repair damaged DNA effectively, making them particularly vulnerable to metronidazole’s action. The drug enters the bacterial or parasitic cell and is activated, creating toxic compounds that disrupt the DNA structure.
This disruption prevents the microorganism from replicating, essentially halting its growth and leading to its eventual death. It’s a bit like dismantling a complex machine by interfering with its blueprints – once the instructions are scrambled, the machine can no longer function. This targeted action is why metronidazole is so effective against anaerobic infections while generally sparing beneficial bacteria in your gut.
The drug’s effectiveness hinges on its ability to penetrate these organisms and disrupt their DNA replication process. It’s a sophisticated mechanism that has made metronidazole a cornerstone of treatment for various infectious diseases. Understanding this basic principle helps appreciate why adherence to the prescribed dosage and duration is so important – ensuring sufficient drug levels to effectively target the invading microorganisms.
Contraindications: Who Should Avoid Metronidazole?
While metronidazole is generally safe when used appropriately, certain conditions preclude its use. Individuals with severe liver failure should not take this medication, as it can exacerbate their condition. Similarly, those with active neurological diseases may experience worsening symptoms.
A history of allergy to metronidazole or any other nitroimidazole derivative (a class of similar drugs) is a strict contraindication. If you’ve previously experienced an allergic reaction – such as hives, swelling, or difficulty breathing – avoid this medication at all costs. Furthermore, individuals undergoing treatment with certain medications, like busulphan, cancer chemotherapy drugs, ciclosporin, disulfiram, fluorouracil, lithium, phenobarbital, phenytoin, and warfarin-type anticoagulants should exercise extreme caution and consult their doctor before starting metronidazole.
It’s also important to reiterate that Dr Fox does not prescribe metronidazole for pregnant or breastfeeding women due to potential risks to the developing fetus or infant. Always provide a complete medical history to your healthcare provider to ensure metronidazole is safe for you.
Interactions: What To Watch Out For
Metronidazole can interact with several other medications and substances, potentially altering their effects or increasing the risk of side effects. The most significant interaction involves alcohol – as previously mentioned, combining metronidazole with alcohol can trigger a disulfiram-like reaction, causing unpleasant symptoms like nausea, vomiting, dizziness, and chest pain.
Beyond alcohol, be cautious when taking metronidazole alongside blood thinners (warfarin), as it can enhance their anticoagulant effect, increasing the risk of bleeding. Similarly, interactions with certain chemotherapy drugs, such as fluorouracil, may increase their toxicity. It’s also important to avoid combining metronidazole with disulfiram, a medication used to treat alcoholism, as this could intensify the adverse effects of both drugs.
Even seemingly harmless substances can interfere with metronidazole’s effectiveness. For example, certain antacids or medications that alter stomach acidity might affect its absorption. Always inform your doctor about all medications you are taking, including over-the-counter drugs, herbal supplements, and vitamins, to avoid potentially harmful interactions.
Side Effects: What To Expect
Like all medications, metronidazole can cause side effects, although not everyone experiences them. Common side effects are generally mild and include nausea, vomiting, diarrhea, loss of appetite, numbness or tingling in the extremities, a metallic taste in the mouth, and skin dryness. These symptoms usually subside on their own as your body adjusts to the medication.
Less common side effects may include dizziness, drowsiness, headache, and dark urine. If you experience any of these, consult your doctor. However, certain side effects require immediate medical attention. These include signs of a severe allergic reaction (swelling of the face, lips, tongue, or throat; difficulty breathing), fever, stiff neck, confusion, hallucinations, or seizures.
Rarely, metronidazole can cause more serious side effects like encephalopathy (brain inflammation) or severe skin rashes. If you notice any unusual or concerning symptoms while taking this medication, don’t hesitate to seek medical help promptly. Remember, the benefits of treatment often outweigh the risks of mild side effects, but it’s crucial to be aware and vigilant.
Overdose Risks: What To Do
An overdose of metronidazole is rare but can occur if you take more than your prescribed dose or accidentally ingest a large amount of the medication. Symptoms of an overdose may include nausea, vomiting, diarrhea, dizziness, confusion, seizures, and even coma in severe cases.
If you suspect an overdose, seek immediate medical attention. Call emergency services (999) or go to the nearest hospital emergency room. Do not attempt to induce vomiting unless instructed by a healthcare professional. Providing information about the amount of metronidazole ingested and when it was taken can help guide treatment decisions.
It’s crucial to store metronidazole securely, out of reach of children and pets, to prevent accidental ingestion. Always follow your doctor’s instructions carefully regarding dosage and administration to minimize the risk of overdose.
Price & Availability in the UK
The price of metronidazole varies depending on the dose, quantity, and where you purchase it. As of 2025, Dr Fox offers 14 tablets of 400mg metronidazole for £9.80 plus a prescription fee (ranging from £1.00 to £4.00 based on order value). Other online pharmacies like Simple Online Pharmacy and Superdrug Online Doctor offer similar products at varying prices – typically ranging from £17.50 to £23.00 for 14 tablets, with additional delivery charges. For a wider range of options and competitive pricing, you can also explore Medicade.
Metronidazole is a prescription-only medication in the United Kingdom, meaning you cannot purchase it over the counter. However, online pharmacies like https://medicade.co.uk/ offer convenient access to prescriptions through online consultations and UK pharmacy dispatch. This allows patients to obtain the medication legally and safely from the comfort of their homes.
Here’s a table showing estimated delivery times for various cities in the UK:
| City | Estimated Delivery Time |
|---|---|
| London | 1-3 working days |
| Manchester | 2-4 working days |
| Birmingham | 2-4 working days |
| Glasgow | 3-5 working days |
| Cardiff | 2-4 working days |
Alternatives to Metronidazole
While metronidazole is a highly effective treatment for many infections, several alternatives are available. For bacterial vaginosis, clindamycin tablets (300mg twice daily for 7 days) or metronidazole vaginal gel (Zidoval – every night for 5 nights) offer alternative delivery methods and may be suitable for individuals who prefer to avoid oral medication.
In some cases, natural alternatives are explored, though their effectiveness is often less well-established than pharmaceutical options. Probiotics containing lactobacilli can help restore the natural balance of bacteria in the vagina, potentially preventing recurrent bacterial vaginosis. However, probiotics should not be used as a substitute for prescribed antibiotics during an active infection.
It’s important to discuss all available treatment options with your doctor to determine the most appropriate course of action based on your individual circumstances and medical history. Each alternative has its own advantages and disadvantages in terms of effectiveness, side effects, and convenience.
Precautions & Important Considerations
Before starting metronidazole, inform your doctor about any allergies you have, especially to nitroimidazole derivatives. Also, disclose all medications you are taking, including over-the-counter drugs, herbal supplements, and vitamins. Be sure to mention if you have liver problems, kidney disease, or neurological conditions.
Avoid alcohol consumption during treatment and for at least 48 hours afterward, as it can cause a disulfiram-like reaction. Store metronidazole in a cool, dry place away from direct sunlight and out of reach of children. Do not share your medication with others, even if they have similar symptoms.
If you are pregnant or breastfeeding, discuss the risks and benefits of metronidazole with your doctor before taking it. Always complete the full course of treatment as prescribed, even if you start feeling better before it’s finished. If you experience any unusual or concerning side effects, seek medical attention promptly.
Frequently Asked Questions (FAQ)
Q: Can I drive while taking metronidazole? A: Metronidazole can cause drowsiness and dizziness in some individuals. Avoid driving or operating machinery if you experience these symptoms.
Q: What should I do if I miss a dose? A: Take the missed dose as soon as you remember, unless it’s almost time for your next scheduled dose. Do not double up to catch up.
Q: Can metronidazole interact with food? A: While there are no major dietary restrictions, taking metronidazole with food can help reduce stomach upset.
Q: How long does it take for metronidazole to work? A: Symptoms typically start improving within a few days of starting treatment, but it’s important to complete the full course as prescribed.
Reviewed by a Medical Professional
Reviewed by a medical professional Isabel D White.
