Leaflet: Information for the user
Flagyl 500 mg vaginal tablets
metronidazole
Read this leaflet carefully before starting to use this medicine, as it contains important information for you.
Contents of the leaflet
Flagyl 500 mg vaginal tablets are an anti-infectious medicine belonging to the group of imidazoles.
Antibiotics are used to treat bacterial infections and are not effective against viral infections such as the flu or the common cold.
It is essential to follow the instructions regarding dosage, administration interval, and treatment duration indicated by your doctor.
Do not store or reuse this medicine. If you have any leftover antibiotic after completing treatment, return it to the pharmacy for proper disposal. Do not throw medicines down the drain or in the trash.
They are used to treat infections caused by parasites and bacteria that are susceptible to this medicine. The infections that can be treated with Flagyl 500 mg vaginal tablets are those caused by Trichomonas, such as urethral inflammation (urethritis) and vaginal inflammation (vaginitis).
Do not use Flagyl 500 mg vaginal tablets
Warnings and precautions
Consult your doctor or pharmacist before starting to use Flagyl 500 mg vaginal tablets:
There have been reports of severe liver toxicity/liver failure, some of which were fatal, in patients with Cockayne syndrome taking metronidazole.
If you have Cockayne syndrome, your doctor should closely monitor your liver function while you are being treated with metronidazole and afterwards.
Inform your doctor immediately and stop taking metronidazole if you experience:
There have been reports of severe cutaneous bullous reactions with metronidazole, such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), or acute generalized exanthematous pustulosis (AGEP) (see "Possible side effects"). If symptoms or signs of AGEP, SJS, or TEN appear, treatment with Flagyl should be discontinued immediately.
If you are going to have a blood test, inform your doctor or nurse that you are taking Flagyl. Flagyl may alter the results of some blood tests.
Using Flagyl 500 mg vaginal tablets with other medicines
Inform your doctor or pharmacist if you are using, have recently used, or may need to use any other medicine, including those obtained without a prescription.
The concomitant administration of metronidazole and disulfiram (a medicine used to help treat alcoholism) is not recommended, as there have been reports of mental disorders.
The concomitant administration of metronidazole and oral anticoagulant medicines (medicines that help prevent blood clot formation, such as warfarin) may increase the risk of bleeding. If metronidazole is administered with these medicines, you should be closely monitored by your doctor.
There is a risk of elevated blood levels of lithium (a medicine for depression) and cyclosporine (a medicine that reduces the body's defenses) when these medicines are administered concomitantly with metronidazole. Therefore, if they are administered concomitantly, it should be under strict medical control.
Phenytoin and phenobarbital (antiepileptic medicines) increase the elimination of metronidazole, thereby reducing its blood levels.
Metronidazole increases the toxicity of fluorouracil and busulfan (medicines used to treat cancer).
Inform your doctor if you are taking any medicine that may cause changes in heart rhythm (prolongation of the QT interval that can be seen on an ECG), such as certain antiarrhythmics (medicines for heart rhythm disorders), certain antibiotics, and medicines primarily used to control psychosis (including delusions, hallucinations, paranoia, or disordered thinking).
Using Flagyl 500 mg vaginal tablets with food, drinks, and alcohol
Drinks and medicines containing alcohol should not be consumed during treatment with metronidazole until at least one day after treatment, due to the possibility of the so-called Antabus effect, a reaction characterized by skin redness, vomiting, and tachycardia.
Pregnancy, breastfeeding, and fertility
If you are pregnant or breastfeeding, think you may be pregnant, or plan to become pregnant, consult your doctor or pharmacist before using this medicine.
Since metronidazole crosses the placental barrier and there is not enough data to establish its safety during pregnancy, your doctor will carefully assess the convenience of using Flagyl during pregnancy.
Metronidazole is excreted in breast milk, so its administration should be avoided during breastfeeding.
Driving and using machines
During the use of Flagyl, you may feel dizzy or experience vertigo (a sensation of spinning), confusion, hallucinations (seeing or hearing things that do not exist), convulsions (having seizures), or vision problems (such as blurred vision or double vision). If this occurs, do not drive vehicles or use machines.
Flagyl 500 mg vaginal tablets contain wheat starch
This medicine contains wheat starch, 1.6 mg of gluten, which is equivalent to 800 ppm per tablet, and this should be taken into account by patients with celiac disease.
Patients with a wheat starch allergy (different from celiac disease) should not take this medicine.
Follow your doctor's instructions for administering this medicine exactly. If you are unsure, consult your doctor again.
Remember to use your medicine.
Your doctor will indicate your daily dose and the duration of your treatment. Do not stop treatment before completing it. The dose is individualized for you and may be modified by your doctor based on your response to treatment.
If you think the effect of Flagyl is too strong or too weak, inform your doctor or pharmacist.
This medicine should be administered vaginally, placing one tablet at the back of the vagina at night, for 10-20 days. This therapy should always be associated with the administration of metronidazole orally (Flagyl 250 mg tablets).
Whether your partner has symptoms of Trichomonas vaginalisinfection or not, even if laboratory tests are negative, it is necessary for them to be treated with metronidazole orally.
If you use more Flagyl 500 mg vaginal tablets than you should
In case of overdose or accidental ingestion, consult your doctor or pharmacist immediately or call the Toxicology Information Service. Phone: (91) 562 04 20, indicating the medicine and the amount ingested.
An accidental overdose could cause vomiting, lack of coordination, and mild disorientation.
There is no specific antidote for metronidazole overdose. In cases where massive ingestion is suspected, treatment will be based on symptoms.
If you forget to use Flagyl 500 mg vaginal tablets
Do not use a double dose to make up for forgotten doses.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Severe allergic reactions, such as anaphylactic shock.
A certain type of inflammation of the meninges, the membranes that surround the brain and spinal cord (aseptic meningitis).
Frequency not known (cannot be estimated from available data): posterior reversible encephalopathy syndrome (PRES), a brain disorder characterized by symptoms such as headache, confusion, vision problems, and convulsions.
There have been reports of liver failure requiring liver transplantation in patients treated with metronidazole in combination with other antibiotics.
Acute liver failure in patients with Cockayne syndrome (see section 2 "Warnings and precautions").
Reporting side effects
If you experience any of the side effects, consult your doctor or pharmacist, even if they are not listed in this leaflet. You can also report them directly through the Spanish Medicines and Healthcare Products Agency (AEMPS) website: https://www.notificaram.es. By reporting side effects, you can help provide more information on the safety of this medicine.
Keep out of sight and reach of children.
Do not store above 25°C.
Do not use this medicine after the expiration date stated on the packaging after CAD. The expiration date is the last day of the month indicated.
Medicines should not be disposed of via wastewater or household waste. Place the packaging and any unused medicines in the pharmacy's SIGRE collection point. If you are unsure, ask your pharmacist how to dispose of the packaging and any unused medicines. This will help protect the environment.
Composition of Flagyl 500 mg vaginal tablets
Each tablet contains 500 mg of metronidazole.
Appearance of the product and package contents
Each package contains 10 tablets.
Marketing authorization holder and manufacturer
Marketing authorization holder:
Laboratorios Fidia Farmacéutica S.L.U.
Parque Empresarial de la Moraleja - Edificio Torona
Avenida de Europa, 24 - Edificio A - 1 B
28108 Alcobendas - Madrid – España
Manufacturer:
Famar Health Care Services Madrid, S.A.U.
Avda. de Leganés, 62
28923 Alcorcón (Madrid)
Date of the last revision of this leaflet: June 2025
Detailed and updated information on this medicine is available on the website of the Spanish Agency for Medicines and Healthcare Products (AEMPS) http://www.aemps.gob.es/
The average price of FLAGYL 500 mg VAGINAL TABLETS in October, 2025 is around 2.37 EUR. Prices may vary depending on the region, pharmacy, and whether a prescription is required. Always check with a local pharmacy or online source for the most accurate information.