Co-amoxiclav 500mg/125mg – patient leaflet, side effects, dosage

1. What Co-amoxiclav is and what it is used for

Co-amoxiclav is an antibiotic and works by killing bacteria that cause infections. It contains two different medicines called amoxicillin and clavulanic acid. Amoxicillin belongs to a group of medicines called “penicillins” that can sometimes be stopped from working (made inactive). The other active component (clavulanic acid) stops this from happening.

Co-amoxiclav is used in adults and children to treat the following infections:

• middle ear and sinus infections
• respiratory tract infections
• urinary tract infections

• skin and soft tissue infections including

  dental infections

• bone and joint infections.

2. What you need to know before you take Co-amoxiclav

Methotrexate (used to treat cancer and severe psoriasis), penicillins may reduce the excretion of methotrexate causing a potential increase in side effects.

Probenecid (used to treat gout), concomitant use of probenecid may reduce the excretion of amoxicillin and is not recommended. Do not take Co-amoxiclav:

• if you are allergic to amoxicillin, clavulanic

  acid, penicillin or any of the other ingredients of this medicine (listed in section 6).

• if you have ever had a severe allergic

  reaction to any other antibiotic. This can include a skin rash or swelling of the face or throat.

• if you have ever had liver problems or

  jaundice (yellowing of the skin) when taking an antibiotic.

→ Do not take Co-amoxiclav if any of the above apply to you. If you are not sure, talk to your doctor or pharmacist before taking Co-amoxiclav.

Warnings and precautions

Talk to your doctor or pharmacist before taking Co-amoxiclav if you:

• have glandular fever

• are being treated for liver or kidney

  problems

• are not passing water regularly. If you are not sure if any of the above apply to you, talk to your doctor or pharmacist before taking Co-amoxiclav.

In some cases, your doctor may investigate the type of bacteria that is causing your infection. Depending on the results, you may be given a different strength of Co-amoxiclav or a different medicine.

Conditions you need to look out for

Co-amoxiclav can make some existing conditions worse, or cause serious side effects. These include allergic reactions, convulsions (fits) and inflammation of the large intestine. You must look out for certain symptoms while you are taking Co-amoxiclav, to reduce the risk of any problems. See ‘Conditions you need to look out for’ in section 4.

Co-amoxiclav can cause a serious immune system condition, in which the part of the body that fights disease is overactive, and this condition can be life threatening. If you have any of the symptoms listed under ‘Conditions you need to look out for’ in Section 4 while taking Co-amoxiclav, contact your doctor immediately.

Blood and urine tests

If you are having blood tests (such as red blood cell status tests or liver function tests) or urine tests (for glucose), let the doctor or nurse know that you are taking Co-amoxiclav. This is because Co-amoxiclav can affect the results of these types of tests.

Other medicines and Co-amoxiclav

Tell your doctor or pharmacist if you are using, have recently used or might use any other medicines.

• If you are taking allopurinol (used for gout)

  with Co-amoxiclav, it may be more likely that you will have an allergic skin reaction.

• If you are taking probenecid (used for gout), your doctor may decide to adjust your dose of Co-amoxiclav.
• If medicines to help stop blood clots (such as warfarin) are taken with Co-amoxiclav then extra blood tests may be needed.

• Co-amoxiclav can affect how methotrexate

  (a medicine used to treat cancer or rheumatic diseases) works.

• Co-amoxiclav may affect how mycophenolate mofetil (a medicine used to prevent the rejection of transplanted organs) works.

Pregnancy, breast-feeding and fertility

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Driving and using machines

Co-amoxiclav can have side effects and the symptoms may make you unfit to drive. Do not drive or operate machinery unless you are feeling well.

Co-amoxiclav contains sodium

This medicine contains less than 1 mmol sodium (23mg) per tablet, that is to say essentially ‘sodium-free’.

3. How to take Co-amoxiclav

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. Used in adults and children weighing 40 kg and over

The usual dose is:

• 1 tablet three times a day

Use in children weighing less than 40 kg

Children aged 6 years or less should preferably be treated with Co-amoxiclav oral suspension or sachets.

Ask your doctor or pharmacist for advice when giving Co-amoxiclav tablets to children weighing less than 40 kg. The tablets are not suitable for children weighing less than 25 kg. Patients with kidney and liver problems

• If you have kidney problems the dose might be changed. A different strength or a different medicine may be chosen by your doctor.
• If you have liver problems you may have more frequent blood tests to check how your liver is working.

How to take Co-amoxiclav

• Take with a meal.

• Swallow the tablets whole with a glass of water.
• Tablets can be broken along the score line to make them easier to swallow. You must take both pieces of the tablet at the same time.
• Space the doses evenly during the day, at least 4 hours apart. Do not take 2 doses in 1 hour.
• Do not take Co-amoxiclav for more than 2 weeks. If you still feel unwell you should go back to see the doctor.

If you take more Co-amoxiclav than you should

If you have too much Co-amoxiclav, signs might include an upset stomach (feeling sick, being sick or diarrhoea) or convulsions. Talk to your doctor as soon as possible. Take the medicine carton or bottle to show the doctor. If you forget to take Co-amoxiclav

• If you forget to take a dose, take it as soon as you remember.
• You should not take the next dose too soon, but wait about 4 hours before taking the next dose. Do not take a double dose to make up for a forgotten dose. If you stop taking Co-amoxiclav

Keep taking Co-amoxiclav until the treatment is finished, even if you feel better. You need every dose to help fight the infection. If some bacteria survive they can cause the infection to come back.

If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them. The side effects below may happen with this medicine.

Conditions you need to look out for Allergic reactions:

• skin rash

• inflammation of blood vessels (vasculitis)

  which may be visible as red or purple raised spots on the skin, but can affect other parts of the body

• fever, joint pain, swollen glands in the neck, armpit or groin

• swelling, sometimes of the face or throat

  (angioedema), causing difficulty in breathing

• collapse.
• chest pain in the context of allergic reactions, which may be a symptom of allergy triggered cardiac infarction (Kounis syndrome).

→ Contact a doctor immediately if you get any of these symptoms. Stop taking Co-amoxiclav.

Serious immune system condition (haemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS)):

• fever

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• skin rashes
• problems related to nerves, such as shaking or tremor, confusional state
• upper abdominal pain
• yellowing of the skin and/or eyes
• swollen glands in the neck, armpit and/or groin
• bleeding and/or bruising more easily; looking pale, feeling tired.

→ Contact a doctor immediately if you get any of these symptoms. Stop taking Co-amoxiclav. Inflammation of large intestine

Inflammation of the large intestine, causing watery diarrhoea usually with blood and mucus, stomach pain and/or fever. Drug-induced enterocolitis syndrome (DIES)

DIES has been reported mainly in children receiving amoxicillin/clavulanate. It is a certain kind of allergic reaction with the leading symptom of repetitive vomiting (1-4 hours after drug administration). Further symptoms could comprise abdominal pain, lethargy, diarrhoea and low blood pressure.

Acute inflammation of the pancreas (acute pancreatitis)

If you have severe and on-going pain in the stomach area this could be a sign of acute pancreatitis.

→ Contact your doctor as soon as possible for advice if you get these symptoms. Very common side effects

(These may affect more than 1 in 10 people)

• diarrhoea (in adults).

Common side effects

(These may affect up to 1 in 10 people)

• thrush (candida - a yeast infection of the

  vagina, mouth or skin folds)

• feeling sick (nausea), especially when

  taking high doses

  → if affected take Co-amoxiclav with a

  meal

• vomiting
• diarrhoea (in children).

Uncommon side effects

(These may affect up to 1 in 100 people)

• skin rash, itching
• raised itchy rash (hives)
• indigestion
• dizziness
• headache.

Uncommon side effects that may show up in your blood tests:

• increase in some substances (enzymes)

  produced by the liver.

Rare side effects

(These may affect up to 1 in 1000 people)

• skin rash, which may blister, and looks like

  small targets (central dark spots surrounded by a paler area, with a dark ring around the edge - erythema multiforme) → if you notice any of these symptoms

  contact a doctor urgently.

Rare side effects that may show up in your blood tests:

• low number of cells involved in blood

  clotting

• low number of white blood cells. Frequency not known

Frequency cannot be estimated from the available data

• allergic reactions (see above)

• serious immune system condition (see

  above)

• inflammation of the large intestine (see

  above)

• inflammation of the membranes that

  surround the brain and spinal cord (aseptic meningitis)

• Serious skin reactions:

  • a widespread rash with blisters and

    peeling skin, particularly around the mouth, nose, eyes and genitals (Stevens-Johnson syndrome), and a more severe form, causing extensive peeling of the skin (more than 30% of the body surface - toxic epidermal necrolysis)

  • widespread red skin rash with small

    pus-containing blisters (bullous exfoliative dermatitis)

  • a red, scaly rash with bumps under the

    skin and blisters (exanthemous pustulosis).

  • flu-like symptoms with a rash, fever,

    swollen glands, and abnormal blood test results (including increased white blood cells (eosinophilia) and liver enzymes) (Drug Reaction with Eosinophilia and Systemic Symptoms. (DRESS)).

  • a red rash commonly seen on both

    sides of buttocks, upper inner thighs, armpits, neck (Symmetrical

    Drug-Related Intertriginous and Flexural Exanthema (SDRIFE)).

→ Contact a doctor immediately if you get any of these symptoms.

• rash with blisters arranged in a circle with

  central crusting or like a string of pearls (linear IgA disease)

• inflammation of the liver (hepatitis)

• jaundice, caused by increases in the blood

  of bilirubin (a substance produced in the liver) which may make your skin and whites of the eyes appear yellow

• inflammation of tubes in the kidney
• blood takes longer to clot
• hyperactivity

• convulsions (in people taking high doses of

  Co-amoxiclav or who have kidney problems)

  • black tongue which looks hairy. Side effects that may show up in your blood or urine tests:
  • severe reduction in the number of white blood cells
  • low number of red blood cells (haemolytic anaemia)
  • high blood level of protein that stores iron in the body
  • high blood levels of triglycerides, a type of fat
  • crystals in urine leading to acute kidney injury.

Reporting of side effects

If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

By reporting side effects, you can help provide more information on the safety of this medicine.

5. How to store Co-amoxiclav

Keep out of the sight and reach of children Do not use Co-amoxiclav after the expiry date which is stated on the carton. The expiry date (EXP) refers to the last day of that month. Do not store above 25°C.

Store in the original package in order to protect from moisture.

Do not use if the tablets are chipped or damaged.

6. Contents of the pack and other information

What Co-amoxiclav contains

• The active substances are amoxicillin and clavulanic acid. Each film-coated tablet contains 500 mg amoxicillin as amoxicillin trihydrate and 125 mg of clavulanic acid as potassium clavulanate diluted.

• The other ingredients are:

  Tablet core - magnesium stearate, sodium starch glycolate (type A), colloidal anhydorus silica, ,microcrystalline cellulose. Film-coat – opadry White 21K58794

  (hypromellose, titanium dioxide, ethylcellulose, triacetin), isopropyl alcohol, methylene chloride.

What Co-amoxiclav looks like and contents of the pack

Co-amoxiclav 500mg/125mg film-coated tablets are white to off-white, caplet shaped, approx. 20.00 mm x 9.00 mm in dimension, film coated, biconvex tablets, debossed with 'C' and 50’ on either side of breakline on one side and plain on other side.

Co-amoxiclav 500mg/125mg film-coated tablets are supplied in PVDC/PVC blister pack with 1 no. of molecular sieve in Alu pouch. Pack size: 7, 14, 21, 28, 56 and 84 tablets Marketing Authorization Holder and Manufacturer

Ipca Laboratories UK Ltd.

Unit 97-98, Silverbriar,

Sunderland Enterprise Park East,

Sunderland, SR5 2TQ

United Kingdom

This leaflet was last revised in 09/2026 Advice/medical education

Antibiotics are used to treat infections caused by bacteria. They have no effect against infections caused by viruses.

Sometimes an infection caused by bacteria does not respond to a course of an antibiotic. One of the commonest reasons for this to occur is because the bacteria causing the infection are resistant to the antibiotic that is being taken.

This means that they can survive and even multiply despite the antibiotic.

Bacteria can become resistant to antibiotics for many reasons. Using antibiotics carefully can help to reduce the chance of bacteria becoming resistant to them.

When your doctor prescribes a course of an antibiotic it is intended to treat only your current illness. Paying attention to the following advice will help prevent the emergence of resistant bacteria that could stop the antibiotic working.

1. 1. It is very important that you take the antibiotic at the right dose, at the right times and for the right number of days. Read the instructions on the label and if you do not understand anything ask your doctor or pharmacist to explain.
2. 2. You should not take an antibiotic unless it has been prescribed specifically for you and you should use it only to treat the infection for which it was prescribed.
3. 3. You should not take antibiotics that have been prescribed for other people even if they had an infection that was similar to yours.
4. 4. You should not give antibiotics that were prescribed for you to other people.
5. 5. If you have any antibiotic left over when you have taken the course as directed by your doctor you should take the remainder to a pharmacy for appropriate disposal.

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