Flagyl Uses, Side effects, Precautions & Interactions

Flagyl(Metronidazole) is an antibiotic that is a Nitromidazole derivative which is highly effective against most anaerobic bacterial and several protozoal infections such as  E. histolytica, Giardia lamblia, and Trichomonas vaginalis. It also helps in the excretion of guinea worm(Dracunculus medinensis).

Flagyl is effective only against bacterial and protozoal infections. It is not effective against Viral infections such as the common cold and flu.

Mechanism Of Action

Metronidazole (prodrug) enter into microorganism

Nitogroup of the Flagyl accept electrons from ferredoxins

Highly Reactive nitro radical

Damages microbial DNA

Death of the organism (cidal effect)

In the presence of oxygen (aerobes), Highly reactive nitroradicals cannot be generated; hence it is ineffective against the aerobes.

Pharmacokinetics

Flagyl is available for oral,i.v, and topical administration. It is usually well absorbed after oral administration and poorly bound to plasma proteins.

It diffuses well into the tissues including the brain; therapeutic levels are achieved in various body fluids such as saliva, semen, vaginal secretions, bile, breast milk, and CSF. Metronidazole is metabolized in the liver and the metabolites are excreted mainly in the urine.

What are the uses of Flagyl?

Amoebiasis: Metronidazole(400-800mg TDS for 7 to 10 days) is the first-line agent for the treatment of both intestinal and extraintestinal, amoebiasis except in asymptomatic carriers.

Trichomonas vaginitis: Flagyl (400 mg TDS orally for 7 days )is the drug of choice. Both partners should be treated simultaneously.

Giardiasis: Flagyl is very effective and is given orally (200 mg TDS for 7 days).

Anaerobic infections: Metronidazole is effective in most anaerobic infections such as

• Pelvic inflammation disease
• Lung abscess
• Intra-abdominal infections etc

Caused by the B fragilis, Clostridium, and other anaerobic organisms.

• In anaerobic brain abscesses, metronidazole is often used in combination with a third-generation cephalosporin.
• In antibiotic-associated pseudomembranous colitis, metronidazole is effective. It is cheaper and less toxic than vancomycin.
• Vincents angina: Metronidazole is combined usually with amoxicillin for the treatment of vincents angina( ulcerative gingival infection produced by anaerobes)
• In the treatment of H.pylori infections, Flagyl is used in combination with clarithromycin or amoxicillin and PPI( proton pump inhibitors)
• It is used for the prophylaxis of colorectal surgery.

Others.

Also helps in the removal of guinea worm. It can be used in Crohn’s disease.

What are the different side effects?

Flagyl can cause both common and rare side effects. It’s essential to be aware of these potential reactions when taking the medication.

Gastrointestinal Side Effects

Among the most common side effects of Flagyl are gastrointestinal issues. These effects include are nausea vomiting and abdominal pain. While these symptoms are typically mild, they can be bothersome for some individuals.

Neurological Side Effects

Some users may experience neurological side effects such as headaches, dizziness, and peripheral neuropathy (tingling or numbness in the hands and feet). These symptoms are usually transient but should be monitored closely.

Allergic Reactions

In rare cases, Flagyl can trigger allergic reactions. Symptoms may include a rash, itching, or swelling of the face, tongue, or throat.

Effects on the Blood

Flagyl may affect blood cell counts, leading to a decrease in white blood cells or anaemia. While these occurrences are uncommon, they require medical attention if experienced.

Also Read: Clarithromycin: Uses, Side Effects, and Many More

Liver and Kidney Effects

Liver toxicity and kidney problems are potential side effects of Flagyl. It’s crucial to monitor liver function tests during treatment, especially for individuals with pre-existing liver conditions.

Disulfiram-like Reaction

Flagyl can cause a disulfiram-like reaction when taken with alcohol. This reaction may include symptoms such as flushing, nausea, vomiting, and headache, discouraging alcohol consumption during treatment.

Interactions with Alcohol

Consuming alcohol while taking Flagyl can lead to severe reactions due to the disulfiram-like effect. It’s essential to avoid alcohol completely during treatment and for at least 48 hours after the last dose.

Risk Factors for Side Effects

Certain factors may increase the risk of experiencing side effects from Flagyl. These include a history of allergic reactions to antibiotics, liver disease, blood disorders, or neurological conditions.

Managing Side Effects

If side effects occur while taking Flagyl, it’s important to discuss them with a healthcare provider. Sometimes it is effective if we change or switch to another medication.

When to Seek Medical Help?

While most side effects of Flagyl are mild and transient, some may require medical attention. Seek prompt medical assistance if experiencing severe allergic reactions, persistent gastrointestinal symptoms, neurological issues, or signs of liver or kidney problems.

What are the different precautions when you are using Flagyl?

there are several precautions to keep in mind to ensure safe and effective use of the medication. Here are some key precautions:

Follow Doctor’s Instructions: Always take Flagyl exactly as prescribed by your healthcare provider. Do not alter the dosage or stop taking the medication without consulting your doctor first.

Complete the Full Course: Finish the entire prescribed course of Flagyl, even if your symptoms improve before the medication is finished. If you do not complete the full course then it leads to microorganism resistance.

Avoid Alcohol: Do not consume alcohol while taking Flagyl and for at least 48 hours after completing the course of treatment. Combining Flagyl with alcohol can cause a disulfiram-like reaction, leading to severe symptoms such as nausea, vomiting, headache, and flushing.

Inform Your Doctor: Before starting Flagyl, inform your healthcare provider about any medical conditions you have, especially liver disease, kidney disease, blood disorders, or neurological conditions. Also, disclose all medications, supplements, and herbal remedies you are currently taking to avoid potential interactions.

Monitor for Side Effects: Be vigilant for any potential side effects while taking Flagyl. Common side effects may include nausea, vomiting, diarrhoea, headache, dizziness, and a metallic taste in the mouth. If you experience severe or persistent side effects, contact your doctor promptly.

Be Aware of Allergic Reactions: Allergic reactions to Flagyl are rare but can occur. Watch out for symptoms such as rash, itching, swelling of the face, tongue, or throat, and difficulty breathing. Consult with your healthcare provider if you face such allergic reactions.

Use Caution During Pregnancy and Breastfeeding: If you are pregnant, planning to become pregnant, or breastfeeding, discuss the risks and benefits of taking Flagyl with your doctor. While Flagyl is generally considered safe to use during pregnancy if necessary, it’s essential to weigh the potential risks to the fetus or nursing infant.

Store Properly: Ensure that medicine is stored at room temperature protect it from sunlight and moisture and keep this always from the reach of children.

By following these precautions and guidelines provided by your healthcare provider, you can minimize the risk of adverse effects and ensure the safe and effective use of Flagyl for the treatment of bacterial infections.

 What are Different Drug Interactions with Flagyl?

When taking metronidazole (Flagyl), it’s crucial to be aware of potential drug interactions with other medications. Here are some commonly mentioned drugs that may interact with metronidazole:

Warfarin (Coumadin): Metronidazole may increase the effects of warfarin, a blood thinner, leading to an increased risk of bleeding. It’s essential to monitor your blood clotting time closely if taking these medications together and adjust the warfarin dosage as needed under the guidance of your healthcare provider.

Lithium (Eskalith, Lithobid): Metronidazole can increase the levels of lithium in the blood, potentially leading to lithium toxicity. If you are taking lithium, your healthcare provider may need to adjust your dosage and monitor your lithium levels closely while on metronidazole.

Phenytoin (Dilantin): Metronidazole may increase the concentration of phenytoin in the blood, increasing the risk of phenytoin toxicity. Your doctor may need to monitor your phenytoin levels and adjust your dosage accordingly if you are taking both medications simultaneously.

Cyclosporine (Sandimmune, Neoral): Metronidazole may increase the blood levels of cyclosporine, an immunosuppressant medication used to prevent organ rejection in transplant patients. Close monitoring of cyclosporine levels and adjustment of the dosage may be necessary if taking metronidazole concurrently.

Disulfiram (Antabuse): Concurrent use of metronidazole and disulfiram, a medication used to treat alcohol dependence, can lead to a disulfiram-like reaction characterized by severe nausea, vomiting, headache, and flushing when alcohol is consumed. It’s essential to avoid alcohol completely while taking both medications.

Cimetidine (Tagamet): Cimetidine may inhibit the breakdown of metronidazole in the body, leading to increased metronidazole levels and a higher risk of side effects. Your healthcare provider may need to adjust your metronidazole dosage if you are taking cimetidine concurrently.

Fluorouracil (Adrucil): Concurrent use of metronidazole and fluorouracil, a chemotherapy medication, may increase the risk of fluorouracil toxicity. Your doctor may need to monitor you closely for adverse effects if you are taking both medications simultaneously.

Busulfan (Busulfex): Metronidazole may increase the blood levels of busulfan, a chemotherapy medication used to treat certain types of cancer. Your doctor may need to adjust your busulfan dosage and closely monitor you for side effects if you are taking metronidazole concurrently.

It’s essential to inform your healthcare provider about all medications, supplements, and herbal remedies you are taking before starting metronidazole to avoid potential interactions. Your doctor can help determine the safest and most effective treatment plan for you while minimizing the risk of adverse effects from drug interactions.

FAQ

Can I drink alcohol while on metronidazole?

 No, alcohol should be avoided during metronidazole treatment to prevent severe reactions.

Does metronidazole treat viral infections?

No, metronidazole is for bacterial infections only, not viruses like the flu.

What are common metronidazole side effects?

 Nausea, vomiting, diarrhoea, headache, dizziness, metallic taste.

Does metronidazole affect birth control pills?

 It typically doesn’t, but using extra contraception is wise during treatment.

How soon does metronidazole work?

 Improvement often starts within days, but finishing the full course is vital.