Phenoxymethylpenicillin

What phenoxymethylpenicillin is for

Phenoxymethylpenicillin is mainly used to treat bacterial infections, including some:

• ear infections
• throat infections
• chest infections
• skin infections

It's also used to help prevent some infections – for example, in people who:

• have sickle cell disease
• have had their spleen removed

How to take phenoxymethylpenicillin

Phenoxymethylpenicillin comes as tablets and as a liquid that you swallow.

How much you need to take and for how long depends on why you're taking it. Most people need to take it 2 to 4 times a day for a few days or weeks to treat an infection.

If you're taking it to help prevent infections you may take it for longer, sometimes for life.

When taking phenoxymethylpenicillin:

• swallow tablets whole, with a glass of water
• use the syringe or spoon that comes with the liquid medicine to help you measure the right dose
• try to space your doses evenly throughout the day
• take it at least 30 minutes before eating food or at least 2 to 3 hours after food

Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or have any problems taking it.

If you miss a dose of phenoxymethylpenicillin

If you forget to take a dose, take it as soon as you remember, unless it's nearly time for your next dose.

If it's nearly time for your next dose, skip the missed dose and take your next dose at the usual time.

Do not take 2 doses at the same time. Do not take an extra dose to make up for a missed dose.

If you take too much phenoxymethylpenicillin

Taking an extra dose of phenoxymethylpenicillin is unlikely to cause problems, but it's important to get medical advice if you take too much because it can sometimes be dangerous.

Advice about giving medicines to children

• How to give different types of medicines (Medicines for Children website)

Side effects of phenoxymethylpenicillin

Like all medicines, phenoxymethylpenicillin can cause side effects, although not everyone gets them.

Common side effects

Common side effects of phenoxymethylpenicillin include:

• feeling sick (nausea) and being sick (vomiting)
• diarrhoea
• stomach pain or cramps
• loss of appetite
• farting

Phenoxymethylpenicillin will not usually affect your ability to drive, ride a bike or use machinery.

Serious side effects

Phenoxymethylpenicillin can sometimes cause serious side effects, although most of them are rare.

Possible serious side effects of phenoxymethylpenicillin include:

• an allergic reaction (anaphylaxis) – causing symptoms such as a swollen mouth, throat or tongue, difficulty breathing or severe dizziness
• angioedema – causing swelling in areas such as your lips, tongue and face (you have a higher chance of getting angioedema if you have black skin)
• an itchy or painful rash, blisters or sores in your mouth, eyes or genitals – this could be a sign of Stevens-Johnson syndrome
• severe diarrhoea containing blood or mucus

Who can and cannot take phenoxymethylpenicillin

Most adults and children can take phenoxymethylpenicillin, but it's not suitable for some people.

For example, it may not be suitable if:

• you've ever had an allergic reaction or serious side effect from phenoxymethylpenicillin, penicillin or another antibiotic
• you have a condition that affects your stomach and regularly causes you to be sick (vomit)
• you have kidney problems
• you have allergies or asthma

Before taking phenoxymethylpenicillin, tell your doctor if you have any medical conditions.

Breastfeeding and phenoxymethylpenicillin

You can usually take phenoxymethylpenicillin while breastfeeding, but check with a doctor or pharmacist first.

It's rare for breastfed babies to get any side effects from medicine you are taking, but speak to a healthcare professional or call NHS 111 if you have any concerns about your baby.

Pregnancy and phenoxymethylpenicillin

You can usually take phenoxymethylpenicillin if you're pregnant, but it's best to check with a pharmacist or doctor first.

Find out more about taking penicillin antibiotics during pregnancy on the Bumps (Best Use of Medicines in Pregnancy) website

Taking phenoxymethylpenicillin with other medicines, food and drink

There are some medicines, remedies and supplements that may not mix well with phenoxymethylpenicillin.

This includes:

• methotrexate, used to treat immune conditions such as rheumatoid arthritis, psoriasis and Crohn's disease
• some antibiotics, such as tetracyclines, erythromycin and neomycin
• some anticoagulants, such as warfarin
• medicines used to treat gout, such as probenecid

Before taking phenoxymethylpenicillin, tell your doctor or pharmacist if you're taking any medicines, herbal remedies, vitamins or supplements.

Food, drink and alcohol with phenoxymethylpenicillin

You can eat and drink normally while taking phenoxymethylpenicillin.

Try to limit how much alcohol you drink while taking it as alcohol can increase the risk of side effects.

It's best to take phenoxymethylpenicillin 30 minutes before eating food or at least 2 to 3 hours after food.