What is Metronidazole?
Metronidazole is an antibiotic effective against various bacteria and parasites. It's often prescribed for treating different conditions such as skin infections and pelvic inflammatory disease. Additionally, it can be used to treat sexually transmitted infections (STIs) like trichomoniasis.
Trichomoniasis, often known as 'trich', is a common infection caused by a parasite called Trichomonas vaginalis. Symptoms typically show up within a month after being infected, but about half of those who have trich won't experience any symptoms at all.
Trich is caused by a parasite that's typically passed on through unprotected sex. If symptoms appear, they often resemble those of other STIs. Women with the infection might notice soreness around their genitals, along with redness, itching, and a burning feeling. Urination can be uncomfortable, and there may be a clear, yellow, or green discharge with an unusual odour. Men with trich can have similar symptoms, such as irritation inside their genitals, a burning sensation after urinating, and a thin, white discharge from the penis.
How does Metronidazole work?
Metronidazole stops bacteria and parasites from growing, which helps to treat infections. It's one of the most commonly prescribed medicines and is used for a variety of bacterial infections.
The tablets have a 'cytotoxic' effect, which means they can damage certain cells. In practical terms, Metronidazole works by breaking down and eliminating the parasite (Trichomonas vaginalis) responsible for your trich infection.
Metronidazole is often given as a topical cream, lotion, or gel to help with skin conditions such as rosacea. It's also used inside the vagina to treat bacterial vaginosis.
What doses of Metronidazole are there?
For treating trich, Metronidazole is provided in 400mg tablets.
Typically, you would take one 400mg tablet twice daily for a week.
To help you remember to take your Metronidazole tablets and avoid any errors, consider setting an alarm as a reminder. To ensure the infection doesn't come back, it's important to finish the entire course of antibiotics.

- Metronidazole is an antibiotic tablet used to treat trichomoniasis.
- You take it twice a day for seven days.
- It's a quick treatment that gets rid of the infection in just a week.

Metronidazole isn't right for everyone, and there are a few things you should keep in mind when using it.
Here's all the official information on it. If anything doesn't make sense, just let our clinician know, and they can discuss it with you.

Useful Links:
- official info on it.: https://www.medicines.org.uk/emc/product/12817/pil

Q: Is Metronidazole similar to any other treatments for trichomoniasis?
Metronidazole is usually prescribed for most people with a trichomoniasis infection.
It's occasionally given as a one-time 2g dose, but research has shown that this approach is not as effective as taking the antibiotic over a seven-day period.
If you've been advised to take Metronidazole for your trich infection and it doesn't seem to be effective, you might be resistant to this antibiotic, though this is uncommon. If you notice no improvement after finishing your course of tablets, please talk to one of our clinicians.
Q: Does Metronidazole affect contraception?
Metronidazole doesn't interfere with any types of contraception, including emergency contraceptives and the combined pill.
If the tablets cause diarrhoea or make you vomit, they might prevent contraceptives from working effectively if they haven't been fully absorbed into your system yet.
If you experience these side effects from taking Metronidazole, stop using it straight away and inform a healthcare professional. They can guide you on any contraceptives you're using and whether you need to take extra steps to prevent an unplanned pregnancy while you look for a different treatment for trichomoniasis.
Q: Will I get any side effects from using Metronidazole?
Antibiotics such as Metronidazole can occasionally lead to side effects, but they vary from person to person, so it's uncertain which ones you might experience, if any at all.
The leaflet that comes with your medication includes a complete list of possible side effects from taking the tablets.
If you notice any severe side effects, it might indicate an allergic reaction. Look out for symptoms such as swelling of the hands, feet, or throat, skin rashes, skin peeling, and a fever. If you experience any of these, it's important to get medical help straight away by visiting the accident and emergency department at your nearest hospital.
Q: Can you get Metronidazole over the counter?
Metronidazole is a medication that requires a prescription, so you won't be able to buy it over the counter at pharmacies or supermarkets.
Antibiotics must be prescribed by a qualified healthcare professional who can oversee your treatment with Metronidazole. This helps minimise any risks and ensures the tablets are safe for you to take.

How to take Metronidazole
Stopping antibiotics during a course of treatment can mean that some of the pathogen causing your infection is still present in your system. That’s why it’s essential to stick to your dose routine as it’s been advised, and finish the full course of Metronidazole.
Does Metronidazole work right away?
Antibiotics are typically used to treat trichomoniasis. They act swiftly, and after you've completed the course of tablets, you generally won't need any more medication, as this is usually sufficient to eliminate the infection.
You may begin to feel better within a few days of taking Metronidazole, but it's crucial to complete the full 7-day course of tablets to ensure the antibiotics work effectively. If there's no improvement after 7 days, consult a clinician about other STI treatment options.
What should I do if I make a mistake when using Metronidazole?
If you take Metronidazole exactly as your clinician has prescribed, you're unlikely to make any mistakes while using the tablets.
If you've taken more tablets than you should, it's best to head to your nearest hospital straight away for help. It will be easier for the doctor to assist you if you can give them as much information as possible when you arrive, so try to bring the box your Metronidazole tablets came in.
If you miss a tablet of your antibiotics, there's no need to take a double dose. Just wait until it's time for your next dose and carry on with your treatment as usual.
While you're taking Metronidazole, it's important to steer clear of alcohol, as it can lead to vomiting and stomach pain. If you're pregnant or breastfeeding, make sure to inform your healthcare professional before beginning the medication. Metronidazole may occasionally make you feel sleepy or dizzy. If you experience these effects, it's best to avoid driving.