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Phenoxymethylpenicillin for infection

Penicillin V

Make sure you tell your doctor if you are allergic to penicillin. Phenoxymethylpenicillin is a type of penicillin - do not take it if you are allergic to penicillin.

Space your doses out evenly over the day and complete the full course of the antibiotic, even if you feel your infection has cleared up. You should take phenoxymethylpenicillin when your stomach is empty of food (so an hour before you eat, or two hours afterwards).

If you have an allergic reaction (such as any swelling around your mouth, any difficulties breathing or a red rash) contact a doctor straightaway.

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About phenoxymethylpenicillin

Type of medicine

A penicillin antibiotic

Used for

Infections (in adults and children)

Also called

Penicillin V

Available as

Tablets and oral liquid medicine

Phenoxymethylpenicillin is an antibacterial medicine. This means that it stops infections caused by germs (bacteria). It works by killing the germs that are causing the infection.

Phenoxymethylpenicillin is prescribed to treat infections such as chest infections, tonsillitis, cellulitis, ear infections, and dental abscesses. It is used in particular for respiratory infections in children. You may also be prescribed phenoxymethylpenicillin to protect against infection if (for example) you have had rheumatic fever, or if you have sickle-cell disease, or if you have had your spleen removed.

Before taking phenoxymethylpenicillin

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you (or your child) start taking phenoxymethylpenicillin it is important that your doctor (or dentist) knows:

  • If you have an allergic condition (such as asthma, eczema, or hay fever), or if you have ever had an allergic reaction to a medicine. This is especially important if you have ever had a bad reaction to any penicillin antibiotic.

  • If you are pregnant or breastfeeding (although phenoxymethylpenicillin is not known to be harmful to babies).

  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

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How to take phenoxymethylpenicillin

  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about phenoxymethylpenicillin, and it will also provide you with a full list of the side-effects which you may experience from taking it.

  • Take phenoxymethylpenicillin exactly as your doctor tells you to. It is taken four times daily for short-term infections. If you have been prescribed it long-term (to protect from infection) then you will be asked to take one or two doses every day. Your doctor or pharmacist will tell you what dose is right for you to take, and the full directions will also be printed on the label of the pack to remind you about what was said to you. It is important that you space out the doses evenly during the day.

  • If you have been given liquid medicine for a child, read the directions carefully to make sure you measure out the correct amount of medicine.

  • You should take phenoxymethylpenicillin when your stomach is empty, which means taking your doses one hour before you eat any food, or waiting until two hours afterwards. This is because your body absorbs less of the medicine after a meal, which means it is less effective.

  • If you forget to take a dose at your usual time, take it as soon as you remember. Try to take the correct number of doses each day, but do not take two doses at the same time to make up for a forgotten dose.

Getting the most from your treatment

  • Even if you feel your infection has cleared up, keep taking the antibiotic until the course is finished (unless you are told to stop sooner by a doctor). This is to prevent the infection from coming back.

  • A course of treatment for an infection often lasts around seven days, although it can be for up to 10 days. If you still feel unwell after finishing the course, go back to see your doctor. If you have been prescribed phenoxymethylpenicillin to protect you from infection then it is likely you will be asked to take it long-term.

  • After taking a course of an antibiotic, some people develop redness and itchiness in the mouth or vagina. These are caused by an infection commonly known as thrush. If this happens to you, speak with your doctor or pharmacist for advice.

  • This antibiotic can stop the oral typhoid vaccine from working. If you are due to have any vaccinations, make sure the person treating you knows that you are taking this medicine.

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Can phenoxymethylpenicillin cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with phenoxymethylpenicillin. The best place to find a full list of the side-effects which can be associated with your medicine, is from the manufacturer's printed information leaflet supplied with the medicine. Alternatively, you can find an example of a manufacturer's information leaflet in the reference section below. Speak with your doctor or pharmacist if any of the following continue or become troublesome.


phenoxymethylpenicillin side-effects

(these affect around 1 in 10 people)

What can I do if I experience this?

Feeling sick (nausea) or being sick (vomiting), tummy (abdominal) pain

Stick to simple foods


Drink plenty of water to replace any lost fluids. If the diarrhoea continues, becomes severe, or contains blood, let your doctor know


Redness and itchiness (thrush) in the mouth or vagina

Speak with your doctor or pharmacist for advice about treatment

Skin rash, and other allergic-type reactions

Let your doctor know as soon as possible as your treatment may need to be changed

Important: if you develop an itchy rash, swollen face or mouth, or have difficulty breathing, these could be signs that you are allergic to a penicillin antibiotic. Do not take any more phenoxymethylpenicillin, and speak with your doctor or go to your local accident and emergency department straightaway.

If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.

How to store phenoxymethylpenicillin

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

  • If you have been given liquid medicine, store it in a refrigerator. It will have been made up by the pharmacy and lasts for seven days, so check the expiry date on the bottle and do not use it after this date.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

If you buy any medicines, check with a pharmacist that they are safe to take with your other medicines.

If you are having an operation or any dental treatment, tell the person carrying out the treatment which medicines you are taking.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

MHRA - Reporting adverse reactions

Report suspected side effects to medicines, vaccines, e-cigarettes, medical device incidents, defective or falsified (fake) products to the Medicines and Healthcare products Regulatory Agency to ensure safe and effective use.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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