Metronidazole

Metronidazole tablets contain an antibiotic medicine used to treat a range of infections caused by anaerobic bacteria and a microorganism called protozoa. It is most commonly prescribed to treat an infection called bacterial vaginosis (also known as BV), which is a mild infection of the vagina that affects many women throughout their lifetime.

BV is not dangerous but can be unpleasant and many women will seek medical treatment for it. It is caused when there is an upset of the balance of bacteria in the vagina, which leads to an infection. It usually occurs among sexually active women but can happen to any woman at any point in their lives. A common symptom is a greyish-white or yellow discharge from the vagina, with a smelly or ‘fishy’ odour. However, half of all women with BV will notice no symptoms at all.

You should use this antibiotic once you have been diagnosed by a medical professional as having a bacterial infection, such as Bacterial Vaginosis. Metronidazole is safe to use by people who are allergic to penicillin.

You should not take this antibiotic if you are allergic or hypersensitive to any of the ingredients in metronidazole.

Consult your nurse, midwife or doctor before taking metronidazole if you are pregnant, breastfeeding or planning on having a baby. You should avoid taking this medicine if you are pregnant or breast-feeding unless it is considered absolutely necessary.

Avoid drinking alcohol for the duration of your treatment and for at least 48 hours after the course is complete.Always inform your prescribing nurse, doctor or pharmacist if you are taking or have recently taken any other medicines, herbal or otherwise, because metronidazole can sometimes affect the way other medicines work. In particular, consult your doctor if you are taking:

• Lithium, as this can affect the kidneys if taken at the same time as Metronidazole
• Anti-coagulants (blood-thinning agents) like warfarin. You may be required to reduce your dosage of warfarin if you are planning to take Metronidazole
• Medicines to treat epilepsy, like primidone, phenytoin or phenobarbitone
• Disulfiram (for alcoholism)
• Busulfan (for leukaemia)
• 5 fluorouracil (for cancer)
• Ciclosporin (to prevent organ rejection after an organ transplant)

Do not drive, use tools or operate machinery if you experience the following symptoms as a result of taking metronidazole:

• Sleepiness, dizziness or confusion
• Hallucination (seeing or hearing things that are not there)
• Fits or convulsions
• Temporary eyesight problems, like double or blurred vision

Always follow the directions for usage from your nurse, doctor or prescribing pharmacist when taking this medicine. It is important that you finish the full course of treatment to prevent reinfection. The number of tablets you receive will depend on the type of infection you are being treated for, and your dosage will correspond accordingly.

If you are taking this medicine in treatment for bacterial vaginosis (BV), you will receive 10 off-white coloured tablets, which are plain on one side and are engraved with ‘MZ 400’ on the other. This constitutes a full course of treatment for BV. You should swallow one of these 400mg tablet whole with water twice a day for 5 days. Try to space your doses evenly throughout the day, preferably with a meal or snack, and avoid drinking alcohol during and for 48 hours after finishing the treatment. Do not crush or chew the tablets.

If you ever take more metronidazole tablets than you should, speak to your nurse, doctor or contact the Accident and Emergency Department of your local hospital, bringing the original packaging with you so that they know what you have taken.

If you ever forget to take your metronidazole tablets, or miss a dose, take this dose as soon as you remember and carry on with the treatment as usual. If, by this point, it is time for your next dose, skip the original missed dose and continue with the treatment as before. Never take a double dose to make up for one that you have missed.

As with all medicines, it is possible that you may experience side effects from taking metronidazole. Not everybody gets these but it is a good idea to be aware of the warning signs and symptoms of an allergic reaction, and to keep your nurse, doctor or pharmacist informed of any side effects you might be having.

The following side effects will affect less than 1 in 10,000 people. If you notice any of these side effects, tell your nurse, doctor or pharmacist as soon as possible:

• Problems with vision (blurred or double vision)
• Fits or convulsions
• Hallucination (confusion and/or seeing or hearing things that don’t exist)
• Rashes or flushed skin
• Headache
• Dizziness or severe tiredness
• Pains in your joints or muscles
• Darkened urine

There is an extremely small chance that you could suffer a brain disease (encephalopathy) as a result of taking metronidazole. Symptoms of a brain disease vary but, if you experience the following symptoms, stop taking the medication and contact your doctor or the Accident and Emergency Department of your local hospital:

• Hallucination (seeing or hearing things that aren’t there)
• Difficulty speaking or feeling confused
• Problems using your arms or legs
• Headache or a stiff neck
• Fever

If you react badly in any way to metronidazole or experience any symptoms that have not been listed above, inform your nurse, doctor or pharmacist. You can also report any of these symptoms to the Yellow Card Scheme at www.mhra.gov.uk/yellowcard to help provide more information and ensure the safe use of this product.

Stop taking metronidazole immediately and seek medical attention if you are experiencing the following symptoms, as you could be having an allergic reaction:

• Swelling of the feet, ankles, hands, lips, face or throat
• Difficulty breathing or swallowing
• Rashes - lumpy or itchy (hives) or nettle rash (urticaria)