Metronidazole tablets

Metronidazole is an antibiotic that is used to treat bacterial infections. It is a prescription-only medication and can be used to treat infections such as:

• bacterial vaginosis (BV)
• rosacea
• dental abscesses
• trichomoniasis

Metronidazole can come as a tablet, cream, gel, liquid, or a suppository that you insert into your vagina. At Asda Online Doctor, we only prescribe metronidazole tablets for the treatment of bacterial vaginosis and trichomoniasis.

BV is not caused by one single bacterium, but an imbalance in the natural vaginal bacteria. Metronidazole tablets and other treatments for BV work by stopping the growth of the bacteria that are causing the infection, so your body can restore its natural balance.

How long does metronidazole take to work?

Metronidazole tablets are an effective treatment for BV. Some people report improvements after 2 to 3 days, though you need to take your whole course of treatment to fully get rid of the infection.

How effective is metronidazole?

Metronidazole is an effective bacterial vaginosis treatment, with studies finding that it has over a 90% success rate at clearing the infection.

Metronidazole tablets should be swallowed whole with a drink of water and should always be taken during or after a meal. 2 doses of metronidazole tablets are usually recommended for BV:

• a 2g single dose of 5 tablets taken at once
• a 400mg tablet taken twice a day for 7 days (most commonly prescribed)

The single-dose option is 86% effective, while the 7-day, 400mg twice daily course is 97% effective, making both an effective treatment for BV. However, the single-dose option may lead to more side effects. The 7-day course is recommended for people who get BV often.

It is important you do not drink alcohol while you are taking metronidazole, and for 48 hours after, as it can cause severe side effects.

What if I forget a dose?

If you forget to take a dose, you should take it as soon as you remember unless it is nearly time for the next dose. In this case, skip the forgotten dose. You should never take a double dose, as it could cause severe side effects.

Like all medications, metronidazole may cause some people to have side effects. Common side effects of metronidazole include:

• feeling and being sick (nausea and vomiting)
• diarrhoea
• a metallic taste in the mouth or a furry tongue
• headache
• constipation
• pain in the upper abdomen or abdominal cramping

In rare cases, you may get serious side effects. You should speak with your doctor, pharmacist, or 111 if you experience:

• the whites of your eyes or skin turning yellow (jaundice)
• double vision or blurred eyesight
• stomach pains that may also reach your back
• fits (convulsions)

Metronidazole can also cause a serious allergic reaction, and you should call 999 if:

• your lips, mouth, or throat suddenly become swollen
• your throat feels tight, or you are struggling to swallow
• you start to breathe very fast or are struggling to breathe
• you become suddenly very drowsy, confused, or dizzy

How long do metronidazole side effects last?

Side effects of metronidazole usually clear up within a few days once you have stopped using the medication. If side effects persist or get worse, you should speak with your doctor.

What to do if you get side effects

If you get side effects, you can usually manage them at home. You can help:

• nausea, vomiting, and diarrhoea, by staying hydrated, getting plenty of rest, and eating bland foods
• headaches and abdominal pain, by taking over-the-counter medication such as paracetamol or ibuprofen
• constipation, by increasing fibre and fluid intake

For some people, metronidazole may not be the right medication. You should speak with your doctor before taking metronidazole if you:

• are pregnant or breastfeeding
• are allergic to metronidazole
• are under the age of 18
• do not think you can stop drinking alcohol for the length of your treatment

Medication interactions

Some medications can interact with metronidazole and make it potentially unsafe, impacting the effectiveness of the medication. You should tell your doctor if you are taking, have taken, or may take any medication, especially:

• lithium, used to treat depression
• warfarin, used to treat blood clots
• ciclosporin, used to treat autoimmune diseases
• fluorouracil or busulfan, used in some cancer treatments
• phenytoin, used to treat epilepsy
• disulfiram, used to help treat alcoholism

There are no known problems with taking herbal remedies with metronidazole, but you should still let your doctor know.

Medical conditions

To make sure that metronidazole is safe for you to take, you should talk to your doctor if you have any medical conditions, especially:

• liver disease
• kidney disease, or you’re on dialysis
• a central nervous system condition, or a blood disease
• a stomach or intestinal disease, such as Crohn's disease
• a heart rhythm disorder
• Cockayne syndrome

Metronidazole tablets are a prescription-only medication, which means you will need a doctor’s approval to get them. You can request metronidazole tablets for bacterial vaginosis from trusted online services, or you can get a prescription on the NHS.

Can I buy metronidazole 400mg tablets online?

Yes. You can buy metronidazole tablets online with Asda Online Doctor by following these steps:

1. Completing a short online health assessment for one of our doctors to review.
2. Placing your order.
3. If approved, your order will be dispatched and sent to your home address in discreet packaging, or you can choose to collect it from your local Asda Pharmacy 4 hours after a doctor’s approval.
4. If your order is not approved, one of our doctors will contact you through your account with alternative treatment options.

Using our online doctor service means you can get the treatment you need, quickly and conveniently. There’s no need to make an appointment or see anyone face-to-face – all you need is a spare few minutes and an internet connection. You can also get expert advice by messaging a doctor for free through your patient account if you need help with your treatment.

Can I buy metronidazole over the counter?

No, as metronidazole is a prescription-only antibiotic, you cannot buy it over the counter.

Can I get metronidazole on the NHS?

Yes, you can get metronidazole tablets on the NHS, but you will need to make an appointment with your GP to get a diagnosis and a prescription. BV may also be diagnosed and treated at a sexual health clinic.

If you do not react well to metronidazole tablets, or you prefer creams, gels, or vaginal tablets, there are alternative treatment options available. Other BV treatment options include:

• Dalacin cream – a 2% cream containing the antibiotic clindamycin, which is applied by using an applicator to insert the cream into your vagina
• Zidoval vaginal gel – metronidazole vaginal gel which is also inserted directly into the vagina using an applicator
• Fluomizin - a non-antibiotic vaginal tablet that is inserted once a day (one tablet per day) for 6 days.