Co-Amoxiclav (Amoxicillin And Clavulanic Acid)

What Is Amoxicillin and Clavulanic Acid?

Amoxicillin is a penicillin antibiotic that stops infection-causing bacteria from growing. It's used to treat pneumonia, as well as infections of the mouth, ears and urinary tract, among others.

Clavulanic acid is added to amoxicillin to help protect it from being broken down by bacteria. It belongs to a group of medicines called beta-lactamase inhibitors.

Overview

Amoxicillin stops bacteria multiplying by preventing them from building their cell walls. These walls are essential for bacteria to survive and protect themselves from their surroundings. On its own, amoxicillin may be less effective if the bacteria are resistant to it. Clavulanic acid helps by boosting its effect.

How Supplied

The combination comes in 4 forms:

• Regular tablets.
  Taken just before a meal every 8 or 12 hours.
• Chewable tablets.
  Taken just before a meal every 8 or 12 hours. Chew them thoroughly; do not swallow them whole.
• Extended-release tablets.
  Taken with a meal or snack every 12 hours. They should not be chewed or crushed, so swallow the tablet whole and drink enough water afterwards (a glass is usually enough).
• Oral suspension.
  Taken just before a meal every 8 or 12 hours. Shake well to make sure the medicine is properly mixed.

It's best to take the tablets or suspension at the same time each day so you're less likely to forget a dose. Do not take more or less than your doctor has prescribed.

Take amoxicillin and clavulanic acid regularly as prescribed, even if you feel better before the course is finished. Stopping too soon or missing doses can mean the infection is not fully treated and may come back. It can also make the bacteria more resistant, which may limit treatment options later on.

Indications and Uses of Amoxicillin and Clavulanic Acid

It's important to know what amoxicillin and clavulanic acid is used for. Before taking it, you need to be sure the infection is caused by bacteria that can be treated with Augmentin or similar medicines. Otherwise, drug-resistant bacteria may increase, making future treatment less likely to work.

It's best if the doctor has culture results, but if not, local epidemiology patterns in the UK may help guide the choice of treatment.

So, what does the combination treat?

Lower Respiratory Tract Infections

Lower respiratory tract infections affect the lungs and the parts of the airways below the voice box. Bronchitis and pneumonia are among the most common. They may be caused by isolates of Moraxella catarrhalis and Haemophilus influenzae.

Acute Bacterial Otitis Media

Acute bacterial otitis media can develop after allergies, a sinus infection, a cold, flu or exposure to excess cigarette smoke, among other causes. It may also be caused by isolates of Haemophilus influenzae (H. influenzae) and Moraxella catarrhalis (M. catarrhalis).

Sinusitis

Sinusitis is inflammation of the paranasal sinuses, either acute or chronic. It may be caused by severe allergies, bacteria (beta-lactamase-producing isolates of H. influenzae and M. catarrhalis), fungi and other factors.

Skin and Skin Structure Infections

Skin and skin structure infections, whether complicated or uncomplicated, are usually caused by beta-lactamase-producing isolates of bacteria such as:

• Escherichia coli;
• Staphylococcus aureus;
• Klebsiella species.

Urinary Tract Infections

Urinary tract infections, which can affect the ureters, urethra, bladder or kidneys, are usually caused by isolates of:

• Klebsiella species;
• Escherichia coli;
• Enterobacter.

Limitations of Use

Clavulanic acid and amoxicillin should not be used if testing shows the bacteria are susceptible to amoxicillin alone.

Dosage

The dose of amoxicillin & clavulanic acid varies depending on age, weight and the form of the medicine used.

Some dosing recommendations for adults or children weighing over 40 kg are:

• A 500 mg tablet every 8 to 12 hours (2-3 times a day);
• A 250 mg tablet every 8 hours (3 times a day);
• 875 mg every 12 hours (2 times a day);
• 2000 mg every 12 hours (2 times a day) for complicated conditions.

The dose is based solely on the amount of amoxicillin needed to treat the infection.

If a child weighs less than 40 kg, the recommended dose is usually between 20-45 mg per kilogram 2-3 times a day.

To help reduce side effects such as an upset stomach, take your doses with food and do not take more than one tablet at a time. Too much clavulanic acid may also upset your stomach. Also, keep in mind that:

• The 250 mg and 500 mg tablets contain the same amount of clavulanic acid, so you should not take two 250 mg tablets if your prescription says to take one 500 mg tablet;
• You should not swap regular tablets for chewable tablets.

Side Effects

Amoxicillin & clavulanic acid can cause a range of side effects. Some of the most common are:

• Abdominal discomfort;
• Diarrhoea;
• Excess gas;
• Bloating;
• Heartburn;
• Nausea and vomiting;

Side effects can be grouped into two categories: those that need immediate medical attention and those that do not.

Side effects requiring immediate medical attention

If you have any of the following side effects from amoxicillin / clavulanic acid, get medical help as soon as possible:

• Severe itching and skin rash;
• Difficulty swallowing or breathing;
• Severe vaginal itching and discharge;
• Yellowing of the eyes and/or skin;
• Bloody diarrhoea;
• Darker urine than usual;
• High fever;
• Weakness, drowsiness and confusion;
• Severe swelling of the tongue and/or face;
• Other unusual allergic reactions;
• Easy bruising, etc.

Keep in mind that if you develop severe or unusual side effects after taking amoxicillin and clavulanic acid, you can report them through the MHRA Yellow Card scheme. Ask your doctor about the best way to describe your symptoms.

There are also rare side effects, including seizures, anaphylaxis, a shortage of red blood cells and inflammation of the colon. Antibiotics do not only kill harmful bacteria - they can also affect the helpful bacteria in your gut. This can lead to digestive problems. Ask your doctor before taking probiotics during or after your antibiotic course.

Side effects not requiring immediate medical attention

Some side effects do not need immediate medical help. They are usually mild, but you should still tell your doctor about them so they do not get worse:

• Regular diarrhoea;
• Nausea and vomiting;
• Upset stomach;
• Mild bloating;
• Mild skin rash.

If you are thinking about taking another medicine to help with these side effects, speak to your doctor first.

Drug Interactions

Medicines containing amoxicillin and clavulanic acid can interact with certain substances. Do not take any additional medicine without first checking with your doctor.

Here are some medicines that interact with Augmentin and similar treatments:

• Probenecid is commonly used to treat gout. One effect of it is that it prevents amoxicillin from being cleared by the kidneys. This can cause amoxicillin to build up to toxic levels and lead to complications.
• Birth control pills.
  The combination may reduce or stop the effect of oral contraception. If you are not using additional contraception, this could result in an unplanned pregnancy.
• If you are taking Zyloprim, Aloprim or other medicines containing allopurinol, amoxicillin and clavulanic acid may be more likely to cause a skin rash.
• Oral anticoagulants.
  Combining oral anticoagulants with amoxicillin may increase the International Normalised Ratio (INR). To help both medicines work as intended, your doctor may need to adjust the anticoagulant dose.

It can help to write down all the medicines and dietary supplements you take before starting a course of amoxicillin and clavulanic acid. That way, you are less likely to forget anything and your doctor can adjust the dose if needed.

Warnings & Precautions

There are several warnings and precautions to consider before taking amoxicillin and clavulanic acid. Here are the main points to keep in mind:

• Know your allergies.
  If you are allergic to medicines such as Trimox, Amoxil, Wymox, or others containing amoxicillin, clavulanic acid or penicillin, tell your doctor. If you are not sure of the medicine name or type, describe the allergic reactions you have had.
• Remember all medicines you are taking.
  As you can see, amoxicillin and clavulanic acid can interact with many substances. Some of these are easy to overlook, so take a list of all medicines and supplements with you when you see your doctor in the United Kingdom. This helps your treatment go as smoothly as possible and may reduce side effects.
• Tell your doctor about any medical conditions.
  If you have severe allergies, asthma, liver or kidney disease, mononucleosis, hay fever, hives or other conditions, tell your doctor before testing.
• Think about whether you plan to become pregnant.
  If you are planning a pregnancy, are already pregnant or are breastfeeding, tell your doctor in advance. If you become pregnant while taking amoxicillin, contact your doctor as soon as possible. Remember that you should use additional contraception rather than relying only on birth control pills while taking amoxicillin.
• Plan your diet.
  Ask your doctor whether you need to make any changes to your diet. Major changes are not usually needed, but diet may still matter when supplements or other medicines are involved. There are no known problems linked to drinking alcohol with amoxicillin and clavulanic acid.
• See your doctor regularly.
  Do not miss your laboratory appointments. There may be additional tests needed to check that treatment is working well and that no extra medicine or dose change is needed.
• Use the right test if you have diabetes.
  For urine glucose tests, use TesTape or Clinistix. Avoid Clinitest, as it may give false results if you are taking amoxicillin regularly.
• Do not give your medicine to anyone else.
  Usually, a prescription for amoxicillin and clavulanic acid is not refillable. If you give someone else a tablet, you may miss your final dose and put your recovery at risk. If you finish the course but still have symptoms of infection, contact your doctor as soon as possible.

These warnings are straightforward and can help you get the best results from treatment for a bacterial infection.

Hypersensitivity Reactions

If you have ever had penicillin hypersensitivity, you must tell your doctor. Ignoring this could lead to an anaphylactic reaction, which can be fatal. If penicillin is not on your allergy list but you have many other allergies, it is still worth showing the list to your doctor.

Before starting Augmentin or similar medicines, you should speak to your doctor to reduce the risk of serious side effects. If you notice an unusual allergic reaction, contact your doctor and stop taking the medicine until you are told what to do next.

Hepatic Dysfunction

Hepatitis and cholestatic jaundice are among the serious side effects that can occur in patients with liver impairment who take amoxicillin and clavulanic acid. In most cases this hepatitis is reversible, but fatal cases have been reported.

These patients need regular monitoring to check whether liver toxicity can be reversed. The groups most at risk are:

• Men;
• Older people;
• Patients treated with the same medicines for a long time.

Even if you stop taking the medicine, this side effect can still appear within the next couple of months.

Clostridium difficile-associated diarrhea (CDAD)

CDAD is a common side effect of many antibacterial medicines. When the normal balance of bacteria in the body is disrupted, bacteria in the colon can react and cause inflammation and other problems. CDAD can range from a mild, easily treated illness to fatal colitis.

CDAD should be considered in anyone taking antibacterial treatment who develops diarrhoea. The condition can become serious and may be difficult to treat. Some patients may need a colectomy. Even if the problem starts within 2 months after treatment ends, it may still be related. This is another reason why an accurate medical history is important.

If a patient is diagnosed with CDAD, any antibacterial treatment not being used to treat it should be stopped. Follow-up treatment may include protein supplements, management of fluids and electrolytes, another antibacterial medicine against Clostridium difficile (C. difficile), and surgical assessment if the condition becomes severe.

Skin Rash in Patients With Mononucleosis

Amoxicillin and clavulanic acid are not recommended for patients with mononucleosis. A skin rash is very likely to occur and complications may follow.

Potential for Microbial Overgrowth

Like any antibacterial treatment, this medicine can disrupt the normal balance of bacteria in the body and allow another organism to overgrow. If this is not properly controlled, it can lead to a superinfection. If this is suspected, the current antibacterial treatment should be stopped and further tests should be carried out to guide a new treatment plan.

Phenylketonurics

People with the metabolic disorder phenylketonuria should be very careful when taking amoxicillin / clavulanic acid/potassium medicines such as Augmentin. The brand's chewable tablets and powder for suspension contain aspartame, which provides phenylalanine and may cause problems in people with phenylketonuria.

Regular and extended-release tablets do not contain this substance.

Development of Drug-Resistant Bacteria

Augmentin and similar medicines should only be prescribed when a bacterial infection has been confirmed. If not, the treatment is unlikely to help and may encourage the growth of drug-resistant bacteria. If the patient later develops another bacterial infection, treatment may be less effective.

Use in Specific Populations

The dose may vary depending on the patient group, such as pregnant or breastfeeding women, children under or over 40 kg, and older adults.

Pregnancy

If the patient is not allergic to penicillin, this antibacterial treatment may be used and there should be no teratogenic effects. However, it is worth noting that this has not been well studied. Some reproduction studies in pregnant mice showed that doses of 1200 mg/kg daily did not affect the fetus. This was several times higher than the maximum dose used in humans.

Animal findings are not always the same as human outcomes, however. Treatment should therefore only be prescribed after a bacterial infection has been confirmed.

Labor and Delivery

There is no clear information on whether amoxicillin and/or clavulanic acid or potassium clavulanate affects the fetus or changes the length of labour.

It is known, however, that oral ampicillin-type antibiotics are not well absorbed during labour.

Nursing Mothers

Amoxicillin and clavulanic acid pass into breast milk and may cause digestive problems in infants. Medicines containing either substance should therefore be prescribed to breastfeeding women with caution and only when clearly needed.

Pediatric Use

The dose must be adjusted according to the child's age and/or weight:

• Infants younger than 3 months old should only have 30 mg/kg daily, 2 times a day;
• For patients aged 3 months and over, the dose depends on the diagnosis and weight;
• Patients weighing over 40 kg can receive adult doses according to the prescription.

Keep in mind that chewable tablets and oral suspension should not be prescribed to patients with phenylketonuria. Regular tablets are also not recommended before a child weighs 40 kg because the ratio of ingredients is different. Amoxicillin is also cleared more slowly from the body in infants.

Geriatric Use

Clinical study analyses of medicines containing amoxicillin and clavulanic acid (Augmentin) included around 3,100 patients in total. Of these, 32% were aged 65 and over, and some were aged 75 or older.

No major differences in response were found between older and younger patients. No differences in safety or effectiveness were seen unless the patient had increased sensitivity to one or more components of the medicine, or had metabolic or kidney dysfunction.

Some patients may need testing for these conditions before the medicine is prescribed.

If a patient of any age has impaired kidney function, the response to amoxicillin can be more complicated. The substance is mainly excreted by the kidneys, so they need to be working reasonably well to reduce the risk of unwanted effects. Dose selection should be guided by whether or not the patient has kidney disease.

Undesirable Effects

The undesirable effects are linked to overdose or missed doses of amoxicillin and clavulanic acid. Make sure you have a schedule and follow it carefully. Some symptoms of penicillin overdose include:

• Severe stomach pain;
• Diarrhoea;
• Skin rash;
• Nausea and vomiting;
• Drowsiness or hyperactivity;

Remember that taking your medicine at the same time every day can reduce the risk of overdose or missed doses.

Overdose

If an overdose happens:

• Stop taking the medicine immediately;
• Treat the symptoms to ease the condition;
• Drink plenty of fluids;
• Take other supportive measures to keep the person stable;
• Call a doctor.

If the dose was not over 250 mg per kg, there may be no serious symptoms or consequences, but it is still recommended to contact a doctor for further instructions. If the dose was much higher, interstitial nephritis may develop and lead to kidney failure if not treated immediately.

Crystalluria is another sign of penicillin overdose and may also lead to kidney failure.

It is important to maintain good fluid intake and diuresis in the event of an overdose.

Kidney impairment caused by overdose may improve after stopping the medicine and removing excess amoxicillin and/or clavulanic acid by haemodialysis.

Missed Dose

Missing a dose is generally less dangerous than taking too much, but you should take it as soon as you remember unless it is nearly time for your next dose. Never take a double dose to make up for a missed one, as this may lead to overdose.

Storage

Here are some key points on storing medicines containing amoxicillin/clavulanic acid:

• Keep the medicine in its original container;
• Keep it out of the reach of children and pets;
• Keep the container tightly closed at all times;
• Store it somewhere that is not too hot or humid (room temperature is usually best);
• If you are using a liquid medicine, keep it in the fridge but do not freeze it;
• Throw the liquid away if it has not been used within 10 days.

It is very important to keep medicines well out of the reach of children. Many drops, creams and other medicines do not come with child-resistant packaging, so even when closed tightly, they may still be easy to open.

Choose a storage place carefully - somewhere high up and out of reach of young children. According to Up and Away, about 50,000 children are taken to A&E departments because of their "experiments" with unknown containers of medicines.

It's also important to know how to dispose of unwanted medicines properly. Dispose of them in a way that prevents any child, animal or other person from taking them after they've been thrown away. You should also avoid flushing medicines down the toilet, especially in large quantities.

There are take-back schemes for unwanted medicines. You can ask a pharmacist or your GP about the safest way to dispose of them. In the UK, medicines should usually be returned to a pharmacy for safe disposal rather than put in household waste or recycling.

The bottom line

Overall, this combination can be used in pregnant women, children and older people when the right dose is given. Be sure to finish the full course of treatment, don't share the medicine with anyone else, and dispose of any leftover tablets or suspension properly.