Amoxicillin/clavulanic acid

Amoxicillin/clavulanic acid, also known as co-amoxiclav or amox-clav, sold under the brand name Augmentin, among others, is an antibiotic medication used for the treatment of a number of bacterial infections. It is a combination consisting of amoxicillin, a β-lactam antibiotic, and potassium clavulanate, a β-lactamase inhibitor. It is specifically used for otitis media, streptococcal pharyngitis, pneumonia, cellulitis, urinary tract infections, and animal bites. It can be administered orally or intravenously.[4]

Common side effects include diarrhea, vomiting, and allergic reactions. It also increases the risk of yeast infections, headaches, and blood clotting problems.[4][5] It is not recommended in people with a history of a penicillin allergy.[4] It is relatively safe for use during pregnancy.

Amoxicillin/clavulanic acid was approved for medical use in the United States in 1984.[6] It is on the World Health Organization's List of Essential Medicines.[7][8] The World Health Organization classifies amoxicillin/clavulanic-acid as critically important for human medicine.[9] It is available as a generic medication.[6] In 2023, it was the 66th most commonly prescribed medication in the United States, with more than 9million prescriptions.[10][11]

Medical uses

Amoxicillin/clavulanic acid is widely used to treat or prevent many infections caused by susceptible bacteria, such as:

• Urinary tract infections
• Respiratory tract infections
• Skin and soft tissue infections
• Sinus infections
• Tonsillitis
• Cat scratches
• Infections caused by the bacterial flora of the mouth, such as:
• Dental infections
• Infected animal bites
• Infected human bites (including uncomplicated "clenched-fist" or "reverse-bite" injuries)[12]
• Treatment-resistant tuberculosis (see below)
• Diverticulitis

Adverse effects

Possible side effects include diarrhea, vomiting, nausea, thrush, and skin rash. These do not usually require medical attention. As with all antimicrobial agents, antibiotic-associated diarrhea due to Clostridioides difficile infection—sometimes leading to pseudomembranous colitis—may occur during or after treatment with amoxicillin/clavulanic acid.[12]

Rarely, cholestatic jaundice (also referred to as cholestatic hepatitis, a form of liver toxicity) has been associated with amoxicillin/clavulanic acid. The reaction may occur up to several weeks after treatment has stopped and usually takes weeks to resolve. It is more frequent in men, older people, and those who have taken long courses of treatment; the estimated overall incidence is one in 100,000 exposures.[12] In the United Kingdom, co-amoxiclav carries a warning from the Committee on Safety of Medicines to this effect.

As all aminopenicillins, amoxicillin has been associated with Stevens–Johnson syndrome / toxic epidermal necrolysis, although these reactions are very rare.[12][18]

Pharmacology

Amoxicillin is an antibiotic of the penicillin family, while clavulanic acid is a non-antibiotic β-lactamase inhibitor that prevents inactivation of penicillins by certain resistant bacteria.[19]

In addition to its β-lactamase inhibition, clavulanic acid shows central nervous system actions and effects and has been studied in the potential treatment of various psychiatric and neurological disorders.[20][21][22][23][24]

History

British scientists working at Beecham (now part of GlaxoSmithKline) filed for patent protection for the drug combination in 1977, which was granted in 1982.[25]

It was sold under the brand name Augmentin.[26][27]

Preparations

Amoxicillin/clavulanic acid is the International Nonproprietary Name (INN) and co-amoxiclav is the British Approved Name (BAN).

Many branded products indicate their strengths as the quantity of amoxicillin. Augmentin 250, for example, contains 250 mg of amoxicillin and 125 mg of clavulanic acid.[26][28]

An intravenous preparation has been available in the UK since 1985,[29] but no parenteral preparation is available in the US; the nearest equivalent is ampicillin/sulbactam.

Suspensions of amoxicillin/clavulanic acid are available for use in children. They must be refrigerated to maintain effectiveness.

Veterinary use

Amoxicillin/clavulanic acid is used in numerous animals for a variety of conditions:

• Dogs: Skin and soft tissue infections such as wounds, abscesses, cellulitis, superficial/juvenile and deep pyoderma due to susceptible strains of the following organisms: β-lactamase-producing Staphylococcus aureus, non-β-lactamase-producing Staphylococcus aureus, Staphylococcus spp., Streptococcus spp., and E. coli; and periodontal infections due to susceptible strains of both aerobic and anaerobic bacteria.[30]

• Cats: Skin and soft tissue infections such as wounds, abscesses, and cellulitis/dermatitis due to susceptible strains of the following organisms: β-lactamase-producing Staphylococcus aureus, non-β-lactamase-producing Staphylococcus aureus, Staphylococcus spp., Streptococcus spp., E. coli, and Pasteurella spp; urinary tract infections (cystitis) due to susceptible strains of E. coli.[30]