eMedExpert Home > Medications Facts > Amoxicillin Clavulanate (Augmentin)

Augmentin is an oral antibacterial combination consisting of the semisynthetic antibiotic amoxicillin and the beta-lactamase inhibitor, clavulanate potassium (the potassium salt of clavulanic acid).

The presence of clavulanic acid in Augmentin protects amoxicillin from degradation by beta-lactamase enzymes and effectively extends the antibacterial spectrum of amoxicillin to include many bacteria normally resistant to amoxicillin and other penicillin and cephalosporin antibiotics.

Amoxicillin/Clavulanic Acid was invented around 1977/78 by British scientists working at Beecham, which filed for US patent protection for the drug combination in 1979. U.S. Patents 4,441,609 was granted in 1984.

Amoxicillin is indicated for the treatment of the following infections due to susceptible strains of sensitive organisms:

• Lower respiratory tract infections - tracheobronchitis, bronchitis, pneumonia.
• Otitis media (middle ear infection)
• Sinusitis
• Skin and skin structure infections - cellulitis (infection of the dermis and subcutaneous tissue), erysipelas (superficial form of cellulitis), folliculitis (inflammation of the hair follicles, if the infection of the follicle is deeper and involves more follicles, it moves into the furuncle and carbuncle), furuncles, carbuncles, abscesses, impetigo (large vessicles or honey-crusted sores), infected ulcers and infected burns and other.
• Urinary tract infections (UTI) - infections of thr urinary tract (kidneys, ureters, bladder and urethra)

Off-label and investigational uses of amoxicillin include:

• Antimicrobial prophylaxis in gynecologic surgery4
• Intra-abdominal and pelvic sepsis
• Peritonitis5
  
• Pelvic inflammatory disease7
• Chlamydial infections. Amoxycillin/clavulanic acid may have potential for the treatment of polymicrobial infections involving Chlamydia trachomatis6.

Advantages:

• The main advantage of Augmentin over Amoxicillin is a broader antimicrobal spectrum. Spectrum is the same as amoxicillin with additional coverage of beta-lactamase producing B. catarrhalis, H. influenzae, N. gonorrhoeae, and S. aureus (not MRSA). The expanded coverage of Augmentin combination makes it a useful alternative when amoxicillin resistance is present and persons cannot tolerate alternative antibiotics.
• Can be given without regard to meals. Absorption of amoxicillin/clavulanic acid is not affected by food.
• Excellent tissue penetration. Amoxicillin diffuses readily into most body tissues and fluids, with the exception of brain and spinal fluid.
• Long-established track record in scientific studies and in practice.
• Very effective for middle ear infection (otitis media). Amoxicillin and amoxicillin/clavulanate are preferred beta-lactam antibiotics for the treatment of acute otitis media2.
• Animal and human bites. Because of its anaerobic coverage, amoxicillin/clavulanate is an excellent drug for treating infections caused by human and animal bites.
• In situations when there is increased development of beta-lactamase producing organisms, amoxicillin/clavulanate may be the first choice for the treatment of otitis media, sinusitis, bronchitis, urinary tract infections and skin and soft tissue infections.

Disadvantages:

• More expensive than amoxicillin.
• Increased rate of gastrointestinal side effects, than with amoxicillin alone1. More likely to cause diarrhea than other antibiotics.
  Diarrhea or loose stools is the most common side effect seen with amoxicillin-clavulanic acid
• Risk of liver injury. Can produce a wide range of liver injury including intrahepatic cholestasis without hepatitis, acute hepatocellular injury, and cholestatic hepatitis with hepatocellular necrosis. It can produce cholecystitis-like symptoms. Normalization of liver enzymes usually occurs some time between 11.5-18 weeks after discontinuation of drug. Rarely the liver enzymes remain elevated with resulting chronic liver disease and progression to cirrhosis.
  The most important predisposing factor is age more than 65.
  The reporting rate of hepatitis is on average 9-fold higher for amoxicillin/clavulanic acid than for amoxicillin1.
• Superinfection. Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea and pseudomembranous colitis.
• Like amoxicillin, lacks activity against atypical agents.
• Allergy to amoxicillin (Penicillin hypersensitivity reaction). The penicillin allergy results from the formation of an allergen when the beta-lactam ring reacts with a terminal amine on a lysine residue in a polypeptide. Every time a person is exposed to this allergen, their immune system will sometimes cause an hypersensitivity (anaphylactic) reaction.
• Broad spectrum of antimicrobal activity of amoxicillin/clavulanic acid increases the risk of evolving resistance.

Penicillins are bactericidal antibiotics. Augmentin works by inhibiting the synthesis of bacterial cell walls.

Amoxicillin inhibits bacterial cell wall mucopeptide synthesis. Clavulanic acid inactivates a wide range of beta-lactam enzymes found in bacteria resistant to penicillins and cephalosporins.

The half-life of amoxicillin after the oral administration of Augmentin is 1.3 hours and that of clavulanic acid is 1.0 hour.

• Amoxicillin Clavulanate (Augmentin) versus Other Medications

• 1. Francesco Salvo, Giovanni Polimeni, Ugo Moretti, Anita Conforti, Roberto Leone, Olivia Leoni, Domenico Motola, Giulia Dusi and Achille Patrizio Caputi. Adverse drug reactions related to amoxicillin alone and in association with clavulanic acid: data from spontaneous reporting in Italy. Journal of Antimicrobial Chemotherapy Advance Access published online on April 21, 2007
• 2. Beta-lactam Antibiotics Against S pneumoniae. Pharmacotherapy 19(11):1308-1314, 1999. MedScape
• 3. Cormio G, Bettocchi S, Ceci O, Nappi L, Di Fazio F, Cacciapuoti C, Selvaggi L. Antimicrobial prophylaxis in laparoscopic gynecologic surgery: a prospective randomized study comparing amoxicillin-clavulanic acid with cefazolin. J Chemother. 2003 Dec;15(6):574-8. PubMed
• 4. Cormio G, Vicino M, Loizzi V, Tangari D, Selvaggi L. Antimicrobial prophylaxis in vaginal gynecologic surgery: a prospective randomized study comparing amoxicillin-clavulanic acid with cefazolin. J Chemother. 2007 Apr;19(2):193-7. PubMed
• 5. Grange JD, Amiot X, Grange V, Gutmann L, Biour M, Bodin F, Poupon R. Amoxicillin-clavulanic acid therapy of spontaneous bacterial peritonitis: a prospective study of twenty-seven cases in cirrhotic patients. Hepatology. 1990 Mar;11(3):360-4. PubMed
• 6. Beale AS, Faulds E, Hurn SE, Tyler J, Slocombe B. Comparative activities of amoxycillin, amoxycillin/clavulanic acid and tetracycline against Chlamydia trachomatis in cell culture and in an experimental mouse pneumonitis. J Antimicrob Chemother. 1991 May;27(5):627-38. PubMed
• 7. Uri FI, Sartawi SA, Dajani YF, Masoud AA, Barakat HF. Amoxycillin/clavulanic acid (augmentin) compared with triple drug therapy for pelvic inflammatory disease. Int J Gynaecol Obstet. 1992 May;38(1):41-3. PubMed