Phenoxymethylpenicillin

Phenoxymethylpenicillin is a type of penicillin antibiotic.

It's used to treat bacterial infections, including ear, chest, throat and skin infections.

It can also be used to prevent infections if you have sickle cell disease, or if you have had chorea (a movement disorder), rheumatic fever, or your spleen removed.

Phenoxymethylpenicillin is only available on prescription. It comes as tablets or as a liquid that you swallow.

Most adults and children can take phenoxymethylpenicillin, including during pregnancy and while breastfeeding.

Phenoxymethylpenicillin is not suitable for some people. To make sure this medicine is safe for you, tell your doctor if you have:

• ever had an allergic reaction to phenoxymethylpenicillin, or any other antibiotics or medicine
• kidney problems
• any allergies
• asthma

It's safe to take phenoxymethylpenicillin during pregnancy.

It's OK to take phenoxymethylpenicillin while breastfeeding.

Evidence shows that only tiny amounts of phenoxymethylpenicillin get into breast milk and it would not be expected to cause any side effects in your baby.

If your baby is not feeding as well as usual, has sickness or diarrhoea, oral thrush (mouth thrush) or a skin rash, or if you have any other concerns about your baby, talk to your doctor, pharmacist, health visitor or midwife.

There's no evidence to suggest that taking phenoxymethylpenicillin reduces fertility in either men or women.

These common side effects of phenoxymethylpenicillin happen in 1 in 10 people. There are things you can do to help cope with them:

Stick to simple meals and do not eat rich or spicy food while you're taking this medicine.

Take small, frequent sips of water or squash to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat vomiting without speaking to a pharmacist or doctor.

If you take the combined contraceptive pill or progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.

If you take the combined contraceptive pill or progestogen-only pill and you have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help. If you're in a lot of pain, speak to your pharmacist or doctor.

Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.

Mild allergic reactions

Around 1 in 10 people have an allergic reaction to phenoxymethylpenicillin.

In most cases, the allergic reaction is mild.

You can usually treat a mild allergic reaction by taking antihistamines.

Talk to your doctor or pharmacist if you have a mild allergic reaction and your symptoms get worse.

Serious side effects are rare and happen in less than 1 in 1,000 people.

Call your doctor or call 111 now if you get:

• stomach pain
• a high temperature and watery diarrhoea with blood and mucus in it – this could be a sign that your bowels have become irritated and swollen (inflamed).

Serious allergic reaction

In rare cases, phenoxymethylpenicillin can cause a serious allergic reaction (anaphylaxis).

Call 999 now if:

• your lips, mouth, throat or tongue suddenly become swollen
• you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
• your throat feels tight or you're struggling to swallow
• your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
• you suddenly become very confused, drowsy or dizzy
• someone faints and cannot be woken up
• a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of a serious allergic reaction and may need immediate treatment in hospital.

These are not all the side effects of phenoxymethylpenicillin. For a full list, see the leaflet inside your medicine packet.

Phenoxymethylpenicillin comes as 250mg and 500mg tablets and as a liquid.

There are 2 strengths of liquid available. The lower strength is 125mg/5ml and the higher strength is 250mg/5ml. Both strengths can also come as a sugar free liquid.

The dose of phenoxymethylpenicillin you take depends on your age, how bad the infection is and whether you're taking it to treat or prevent an infection.

Dose for treating infections

The usual dose for adults and children 12 years and over is 500mg, taken 4 times a day.

The usual dose for younger children is:

• children aged 1 month to 11 months have 62.5mg, taken 4 times a day
• children aged 1 to 5 years have 125mg, taken 4 times a day
• children aged 6 to 11 years have 250mg, taken 4 times a day

Sometimes for adults and children, a higher dose is taken twice a day.

Dose for preventing infections

The usual dose for adults and children 12 years and over is 250mg or 500mg, taken 2 times a day.

For preventing infections in younger children it is usually taken 2 times a day. The dose depends on which type of infection is being prevented.

Try to space the doses evenly throughout the day. If you take phenoxymethylpenicillin 4 times a day, this could be first thing in the morning, around midday, late afternoon and at bedtime.

If you're taking it twice a day, leave 12 hours between each dose. For example you could take it at 8am and 8pm.

It's best not to take phenoxymethylpenicillin at mealtimes because food can stop it from working well. Take it 30 minutes before a meal or at least 2 hours after you have eaten.

Swallow phenoxymethylpenicillin tablets whole. Do not chew or break them.

If you or your child are taking phenoxymethylpenicillin as a liquid, your pharmacist will make it up for you.

The medicine will come with a plastic syringe or spoon to help you measure out the right dose. If you do not have one, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.

How long you take it for depends on the type of infection you have.

The usual course of phenoxymethylpenicillin lasts for 5 to 10 days.

If you're taking phenoxymethylpenicillin to prevent infection (for example, if you have sickle cell disease or have had chorea, rheumatic fever or your spleen removed), you may have to take it for the rest of your life.

Carry on taking this medicine until you have completed the course, even if you feel better. If you stop your treatment early, the infection could come back.

If you forget to take a dose, take it as soon as you remember, unless it's nearly time for your next dose. In this case, just leave out the missed dose and take your next dose at the usual time.

Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.

If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

Taking an extra dose of phenoxymethylpenicillin is unlikely to harm you or your child.

Taking more than 1 extra dose could make you feel sick and cause vomiting and diarrhoea. Rest and take it easy until these side effects get better. Speak to your pharmacist or doctor if you're worried.

There are many medicines that do not mix well with phenoxymethylpenicillin.

Tell your doctor if you're taking any of these medicines before you start taking phenoxymethylpenicillin:

• methotrexate
• warfarin, a medicine that helps to prevent blood clots
• gout medicines called probenecid or sulphinpyrazone
• typhoid vaccine (as capsules)
• other antibiotics

It's best not to take herbal remedies and supplements at the same time as phenoxymethylpenicillin. Take phenoxymethylpenicillin at least 2 hours before or after you have taken any herbal remedies or supplements.

Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.