Metronidazole

What is Metronidazole?

Metronidazole is an antibiotic used to treat certain bacterial infections. It is also used to treat certain protozoal infections, including some types of amebiasis and trichomoniasis.

Metronidazole belongs to a group of drugs called antiprotozoal agents, which kills certain types of bacteria and parasites. It comes in the form of oral tablets or a topical vaginal gel called Zidoval.

It works by stopping the growth of organisms in the body and by reducing the production of molecules called free radicals, which can damage cells. This can help to reduce the symptoms of bacterial and parasitic infections.

The tablets stop the growth of the bacteria (or parasite) that is initiating the infection. This prevents the cells' ability to reproduce, stopping the infection from spreading and giving the immune system a better chance of fighting the infection.

When taking any course of antibiotics, it is important to complete the course of treatment, even if you feel better or the infection has cleared. Stopping Metronidazole  too early can cause your infection to return.

Understanding Bacterial Vaginosis:

Metronidazole is a medication often prescribed to treat bacterial infections of the vagina, stomach, skin, joints, and respiratory tract.

Vaginal Bacterial Vaginosis (BV) is a common vaginal infection, affecting 1 in 3 women in the UK.

Though not considered an STI, BV can be initiated through sexual intercourse and may even be transmitted from one woman to another.

What Triggers Bacterial Vaginosis?

The potential causes of BV encompass:

• Using scented products in or around the vagina
• Changing sexual partners
• Vaginal pH changes during menstrual cycles
• Washing underwear with potent detergents
• Using an IUD for contraception

Is Bacterial Vaginosis Comparable to Thrush?

BV is often confused with thrush due to the similar symptoms.

The distinction lies in the vaginal discharge's consistency and odor.

Unlike thrush’s thick, odorless discharge, BV's discharge is often thin, watery, and foul or fishy-smelling.

If you detect a change in vaginal discharge, consult an online prescriber or a pharmacist.

To locate a Pharmacy near you, Visit NHS Find a Pharmacy

Treating Bacterial Vaginosis Online Using Metronidazole

Metronidazole may be requested online if you have been diagnosed with bacterial vaginosis and successfully treated by your GP. You might be eligible for online BV treatment if you:

• Received a diagnosis or had a positive home test for bacterial vaginosis
• Were prescribed Metronidazole and successfully treated the infection
• Have symptoms such as fishy odor and possibly thin discharge

Metronidazole Dosing Regimen

The typical dosing regimen for metronidazole used to treat bacterial vaginosis (BV) is 500 mg twice daily (morning and evening) for seven days.

Depending on the individual patient, doses may range from 250 mg to 1000 mg. 

It is important to always take metronidazole exactly as prescribed by your healthcare provider. Do not take a double dose if you miss a dose. If you have any questions about dosing or any other aspects of treatment, contact your healthcare provider.

What Should I Do If I Forget to Take Metronidazole?

If you forget to take Metronidazole 400mg, take it as soon as you remember.

If it is near the time of your next dose, skip the missed dose and continue taking Metronidazole as you normally would.

To help you remember when to take your next dose of Metronidazole, put your medicine in a place where you are most likely to remember it, or a place where you will see it to prompt you to take it.

Alternatively, you could set a reminder on your phone or smart device which will prompt you near the time of your next dose of Metronidazole.

To learn more on how to take Metronidazole visit the NHS website.

How Will I Know If Metronidazole 400mg Is Safe for Me?

By filling out our confidential medical questionnaire, our prescribers will be able to determine whether Metronidazole is safe for you.

When you order metronidazole online from Prescription Doctor, it is important to inform our doctor of all medications you are taking, including medicines prescribed by your GP or bought over the counter from pharmacies, as well as health and herbal supplements.

Speak to your doctor before using Metronidazole if you:

• are on dialysis
• are pregnant or breastfeeding
• have liver problems
• suspect you have vaginal thrush
• will not be able to stop drinking alcohol while using Metronidazole

Metronidazole has the potential of causing side effects, though not everybody gets them. Understanding the risks associated with the medicine, and remaining vigilant of any side effects is an essential part of your treatment.

Metronidazole Side Effects and Cautions

Before you start taking Metronidazole, you must read the patient information leaflet.

You can view the patient information leaflet for Metronidazole online as a PDF, which you can download or print off for future reference.

Common side effects of Metronidazole may include:

• Diarrhoea
• Metallic taste
• Nausea
• Vomiting

If you notice any of the side effects listed below, speak to your doctor as soon as possible.

• Bleeding gums
• Bruising
• Fatigue
• Stomach pain which radiates to your back (pancreatitis)
• Ulcers in the mouth
• Unexpected infections
• Yellowing of the skin and eyes (jaundice)

Very rare side effects of Metronidazole may include:

• Darkening of urine
• Dizziness
• Fits (convulsions)
• Hallucinations
• Headache
• Liver problems
• Muscle and joint pain
• Rash
• Sleepiness

Metronidazole Interactions

While Metronidazole is very effective at treating these infections, it can also interact with other medications. When taking Metronidazole, or any other medication, it is important to be aware of potential interactions. When taking Metronidazole, it is important to avoid taking it with the following medications:

• Anticoagulants (blood-thinning medications) such as Warfarin
• Certain antacids
• Alcohol
• Bismuth subsalicylate (e.g. Pepto-Bismol)
• Cimetidine (Tagamet) • Lithium • Cotrimoxazole (Bactrim, Septra)
• Disulfiram
• Nitrofurantoin (Macrodantin, Furadantin)
• Phenytoin (Dilantin)
• Sulfonamides such as sulfamethoxazole
• Vancomycin (Vancocin)

It is important to speak to your doctor before taking Metronidazole if you are currently taking any other medications, as they may interact with the antibiotic. Additionally, some foods and beverages may interact with Metronidazole and should be avoided, such as alcoholic beverages and other beverages containing alcohol.

Metronidazole can interact with other medications. This includes;

• Warfarin and other blood-thinning agents
• Lithium
• Medicines used to treat epilepsy
• Certain medications used to treat cancer
• Medications used to treat alcohol dependence
• ciclosporin

Tell your online prescriber about any medications you are currently taking, including herbal remedies and non-prescription medication.

Metronidazole interacts with alcohol and you must abstain from drinking alcohol while taking it. Do not resume drinking until at least two days after you have taken the last tablet.

This is not an exhaustive list of side effects & interactions of Metronidazole. For more information visit BNF Metronidazole Interactions. 

Metronidazole Allergic Reactions

Do not take Metronidazole if you are allergic to Metronidazole or any of its other ingredients listed in the patient information leaflet.

Signs of an allergic reaction include:

• Blue skin or lips
• Collapse or loss of consciousness
• Difficulty breathing
• Dizziness and confusion
• Rash
• Stomach pain
• Swelling of the face, lips, tongue and throat
• Tightness of the chest

Metronidazole During Pregnancy and Breastfeeding

Do not take Metronidazole if you are pregnant, think you might be pregnant, or breastfeeding.

Where Can I Buy Metronidazole Online in the UK?

Metronidazole is available in the UK as oral tablets and as a topical gel. It offers a comprehensive solution for treating bacterial vaginosis.

The medication works by inhibiting the growth of harmful organisms, aiding your immune system in effectively combating the infection. It's a go-to treatment for bacterial vaginosis, a common condition affecting 1 in 3 women in the UK.

How Prescription Doctor Can Assist You

Acquiring Metronidazole through Prescription Doctor is straightforward. After a quick online consultation, our qualified doctors will assess your request. If approved by 3 pm on weekdays, our UK-registered pharmacy will promptly dispatch your medication.

Enjoy the convenience of fast, discreet, and next-day delivery, ensuring you receive your essential medication promptly.

Other Treatment Options for BV

• Zidoval - Vaginal gel that contains Metronidazole which is applied internally into the vagina using the provided applicator.
• 5 day course
• Treat infections locally 

Authored & Reviewed By

Mohamed Imran Lakhi

MPharm - Lead Pharmacist

Imran Lakhi is the superintendent pharmacist and founder at Prescription Doctor. He has been at the core of our team.

Published on: 22/03/2019 Reviewed on: 26/10/2023