What is clavulanic acid used for?

Posted on  February 20, 2021, Edited by Jason, Category  

What is clavulanic acid?

1. Definition

Clavulanic acid belongs to the irreversible competitive beta lactamase inhibitor, which can inactivate the enzyme after being firmly bound to the enzyme, so it has a strong effect not only on the beta lactamase of Staphylococcus aureus, but also on the beta lactamase of Negative bacilli gram. The combination of penicillins and cephalosporins greatly improves the antibacterial activity, and can significantly reduce the minimum inhibitory concentration (MIC).

The drug can increase the effect several times to ten times, so that the drug-resistant strains can restore their sensitivity. Clavulanic acid is a new oxygen-containing nucleus beta lactam antibiotic produced by Streptomyces. Clavulanate potassium is needle-like crystals and is easily soluble in water.

The beta lactamase produced by bacteria hydrolyzing and inactivating certain β-lactam antibiotics is the main mechanism of bacterial drug resistance. Methoxypenicillin was the first semi-synthetic enzyme-resistant penicillin. Subsequently, many semi-synthetic enzyme-resistant penicillins came out, such as oxacillin, cloxacillin and dicloxacillin. Enzyme-resistant penicillin is a reversible competitive beta lactamase inhibitor. When the drug inhibitor is eliminated, the enzyme activity can be restored, so the inhibitory activity of penicillinase is poor, which brings great inconvenience to clinical application.

2. Pharmacology and Toxicology

This product is a broad-spectrum beta lactamase inhibitor, which has only weak antibacterial activity, but has a strong inhibitory effect on various beta lactamases. And it can be firmly combined with most beta lactamases to produce irreversible conjugates and protect penicillins or cephalosporins not resistant to enzymes from enzyme damage, enhance antibacterial activity and expand antibacterial spectrum. Combined with penicillins and cephalosporins, the dosage of clavulanic can be greatly reduced.

Clavulanate potassium is needle-like crystals and is easily soluble in water.

3. Antibacterial effect

Clavulanic acid is a broad-spectrum antibiotic, but its antibacterial activity is very weak. It has an inhibitory concentration of 30~60μg/m1 for Gram-negative bacteria and positive bacteria. It is ineffective against Pseudomonas aeruginosa and Enterococcus. Its MIC for Neisseria gonorrhoeae is 5μg/m1. The MIC of Gram-positive bacteria such as Streptococcus is 12-15μg/ml, the MIC of Bacteroides fragilis is 13.1μg/ml, and the MIC for most other bacteria is 30-125μg/ml.

4. Principle of action

Clavulanic acid is a broad-spectrum inhibitor. It is effective against beta lactamase produced by gram-positive bacteria (such as Staphylococcus aureus) and type I, II, IV and type V beta lactamase produced by gram-negative bacteria, but has weak inhibitory effect on type I cephalosporinase.

Clavulanic acid can broaden the antibacterial spectrum of antibiotics intolerant to beta lactamase, such as penicillin g, ampicillin, amoxicillin or cephalosporin II (cephalothin), increase the antibacterial activity, and increase efficacy of β -Endophthalaminase bacteria, such as Staphylococcus aureus, Escherichia coli, Pneumoniae bacillus, Proteus mirabilis, Proteus vulgaris, Influenza bacillus and Fragile bacillus, etc. However, there is no synergistic effect on amoxicillin or ceftizidine-sensitive bacteria in combination with clavulanic acid.

What is clavulanic acid used for?


The medical data of BRL 25000 reported that oral administration has a good effect on urethral and respiratory tract infections caused by Escherichia coli, various Proteus, Inflammatory bacilli, Influenza bacilli, and pneumococcus.

Clavulanic acid alone is not effective. The enzyme is irreversibly inactivated by being firmly combined with beta lactamase to protect the penicillin or cephalosporin antibiotics that are not resistant to the enzyme from being destroyed, so that they can enter the active site and exert their antibacterial effect, overcoming bacterial resistance to improve curative effect.

In addition, the combination of clavulanic acid and amoxicillin is clinically common, and amoxicillin and clavulanate potassium is a representative drug.

Amoxicillin and Clavulanate Potassium

1. Definition

Amoxicillin and clavulanate potassium is suitable for lower respiratory tract infections, otitis media, sinusitis caused by beta lactamase producing Haemophilus influenzae and Moraxella catarrhalis; urinary tract and skin and soft tissue infections caused by Staphylococcus aureus producing beta lactamase and intestines bacteria producing enzyme such as Escherichia coli and Klebsiella; it can also be used for mild to moderate infections caused by enterococci. This product can also be used for the above-mentioned various infections caused by non-enzyme-producing strains of the above-mentioned bacteria. This product is white or off-white suspended particles, fragrant and sweet. This product is a compound preparation, and its components are amoxicillin and clavulanate potassium.

2. Efficacy and indications

This product is suitable for various infections caused by sensitive bacteria, such as:

  • Upper respiratory tract infection: sinusitis, tonsillitis, pharyngitis, etc.
  • Lower respiratory tract infection: acute bronchitis, acute exacerbation of chronic bronchitis, pneumonia, lung abscess and bronchial co-infection, etc.
  • Urinary system infections: cystitis, urethritis, pyelonephritis, prostatitis, pelvic inflammatory disease, Neisseria gonorrhoeae urinary tract infection and soft chancre, etc.
  • Skin and soft tissue infections: boils, abscesses, cellulitis, wound infections, intra-abdominal sepsis, etc.
  • Other infections: otitis media, osteomyelitis, sepsis, peritonitis and postoperative infections.

3. Pharmacological effects

This product is a compound preparation composed of amoxicillin and Clavulanate potassium in a ratio of 7:1. Amoxicillin and ampicillin have similar anti-sensitive microbial effects. It mainly acts in the reproduction stage of microorganisms by inhibiting the adhesion of cell wall peptides.

Clavulanate potassium has a beta lactam structure similar to penicillin. It can inactivate most of the enzymes produced by bacteria by blocking the active site of beta lactamase, especially for clinically important and plasmid-mediated beta lactamases (these enzymes are usually associated with changes in penicillin and cephalosporin resistance) work better.

The results of in vitro tests and clinical use have shown that this compound is effective against most of the following microorganisms; Gram-positive aerobic microorganisms: Staphylococcus aureus (beta-lactamase-producing and non-beta-lactamase-producing strains) Cillin/oxacillin resistant staphylococci are also resistant to this product.

4. Amoxicillin clavulanate dosage

  • Adults: pneumonia and other moderately severe infections: 625 mg (including amoxicillin 500 mg) orally once every 8 hours, the course of treatment is 7-10 days. General infection: 1 time 375 mg (including amoxicillin 250 mg), once every 8 hours, the course of treatment is 7-10 days.
  • Childrren: Newborns and infants under 3 months: 15 mg/kg every 12 hours based on amoxicillin; dose for children under 40 kg: based on amoxicillin, 25 mg/kg every 12 hours or 20 mg/ every 8 hours for general infection kg, 45 mg/kg every 12 hours for heavier infections, or 40 mg/kg every 8 hours, depending on the severity of the disease. The course of treatment is 7-10 days; the dose of other infections is halved. Children over 40 kg can be administered as an adult dose.
  • Patients with impaired renal function: No need to reduce the creatinine clearance rate> 30ml/min; Amoxicillin 250-500 mg every 12 hours for those with a creatinine clearance rate> 30ml/min; Amoxicillin 250~500 mg every 24 hours for those with a creatinine clearance rate of <10ml/min.
  • Hemodialysis patients: According to the severity of the disease, amoxicillin 250-500 mg is used every 24 hours, and a dose is added during and at the end of hemodialysis.

5. Indications

This product is suitable for lower respiratory tract infections, otitis media, sinusitis caused by enzyme-producing Haemophilus influenzae and Moraxella catarrhalis; enzyme-producing Staphylococcus aureus and enzyme-producing Enterobacteriaceae bacteria such as Escherichia coli, Klebsiella Respiratory tract, urinary tract and skin and soft tissue infections; and it can also be used for mild to moderate infections caused by enterococci. This product can also be used for the above-mentioned infections caused by sensitive non-enzyme-producing bacteria.

Amoxicillin / clavulanic acid side effects


1. Amoxicillin side effects

Patients may have allergic reactions after taking amoxicillin. Allergic reactions of urticaria and skin rash are common adverse reactions in patients treated with amoxicillin. Patients with such adverse reactions may be accompanied by fever, skin itching, pain and even exfoliative dermatitis, profuse sweating, convulsions and other symptoms. Studies have found that allergic reactions caused by amoxicillin generally occur within 3-30 minutes of patients after taking the drug, and have the characteristics of rapid onset and rapid disease progression.

Amoxicillin can enter the kidney cells to play a role, so it can damage the kidney cells of the patient, thereby impairing its kidney function. With age, the kidney function of middle-aged and elderly people gradually declines. If such patients use excessive amoxicillin for treatment, it can increase the burden on their kidneys, slow down the excretion of drugs from the body, and form solid crystals in their urine, which can block their urethra and make them rupture and hemorrhage, leading to symptoms such as blood in the urine and renal colic.

2. Clavulanic acid side effects

Clavulanic acid has small toxicity and little side effects in clinical application. People who are allergic to penicillin should not use it.

3. Clavulanate potassium side effects

  • A few patients may have mild gastrointestinal side effects such as nausea, vomiting and diarrhea. If these side effects occur, drugs can be taken at the beginning of a meal and these symptoms will disappear.
  • Occasionally, urticaria and measles-like rashes occur. When urticaria and severe measles-like rashes occur, stop using this product.
  • A very small number of patients have temporary abnormal liver function, interstitial nephritis, and anaphylactic shock.
  • Very few patients may have neutropenia, eosinophilia, drug fever, and asthma.


Clavulanic acid itself is not very useful, but due to its unique characteristics, it can be combined with other drugs to exert a satisfactory effect. Amoxicillin and clavulanate potassium is a successful case, which can be used to treat a variety of infections.

BALLYA provides a betalactam test to tell you if there are beta lactams residues in dairy products you eat every day.


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