CLAMOXIN 1000 TABLETS

Indications

• Otitis media
• Sinusitis
• Pneumonia
• Bronchitis
• Urinary tract infections
• Skin and soft tissue infections
• H. pylori eradication (as part of combination therapy)

Dosage

Children: Refer to the BNF for Children for appropriate pediatric dosing based on age and weight.

Adults: Refer to the BNF for specific dosing guidelines as dosage may vary depending on the type and severity of the infection.

Mechanism of action

Amoxicillin exerts its antibacterial effect by binding to penicillin-binding proteins (PBPs) located inside the bacterial cell wall. This binding inhibits the transpeptidation enzyme that is crucial for cross-linking peptidoglycan layers, ultimately disrupting cell wall synthesis, leading to bacterial cell lysis and death.

Pharmacodynamics

Amoxicillin shows bactericidal activity, meaning it kills bacteria rather than merely inhibiting their growth. The effectiveness of amoxicillin depends on the susceptibility of the bacteria, and it is typically more effective against rapidly dividing organisms. Resistance can occur, particularly through the production of beta-lactamases by certain bacteria.

Pharmacokinetics

Amoxicillin is well absorbed from the gastrointestinal tract, with food having little effect on its absorption. It achieves peak plasma concentrations within 1-2 hours after oral administration. The drug is widely distributed throughout the body tissues and fluids, including the lungs, liver, and kidneys. Amoxicillin is metabolized minimally in the liver and is excreted primarily unchanged in the urine, with a half-life of about 1 hour in healthy individuals.

Contra-indications

• Hypersensitivity to amoxicillin or other penicillins
• History of severe allergic reactions to beta-lactam antibiotics
• Mononucleosis due to Epstein-Barr virus

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Rash
• Anaphylaxis
• Clostridium difficile-associated diarrhea
• Hepatic dysfunction

Interactions

• Probenecid may increase the serum concentration of amoxicillin
• May reduce the effectiveness of oral contraceptives
• Antibiotics may interact with anticoagulants

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of anaphylaxis in patients with a history of penicillin allergy
• Use with caution in infectious mononucleosis patients due to risk of rash

Pregnancy

Amoxicillin is classified as pregnancy category B. Animal studies have not shown any harm to the fetus, but there are no adequate and well-controlled studies in pregnant women.

Breast-feeding

Amoxicillin is excreted in breast milk. Caution should be exercised when administering to nursing mothers, as it may affect the infant's gut flora.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Oral tablets
• Oral suspension
• Injectable forms

Indications

• Bacterial infections caused by beta-lactamase producing organisms
• Community-acquired pneumonia
• Respiratory tract infections
• Urinary tract infections
• Skin and soft tissue infections

Dosage

Children: Paediatric dosing of clavulanate should be determined based on the specific indication and the formulation used. Refer to the BNF for

Adults: The usual adult dose of clavulanate varies depending on the specific antibiotic it is combined with, generally ranging from 125 mg to 250 mg, taken every 8 hours when combined with amoxicillin.

Mechanism of action

Clavulanate works by irreversibly binding to the active site of beta-lactamase enzymes. By inhibiting these enzymes, clavulanate protects beta-lactam antibiotics from degradation, allowing them to exert their antibacterial effects effectively. This mechanism enhances the spectrum of activity of the co-administered antibiotic, thereby improving clinical outcomes in infections caused by beta-lactamase producing organisms.

Pharmacodynamics

Clavulanate exhibits a time-dependent antibacterial effect, characterized by its ability to maintain effective concentrations against beta-lactamase producing bacteria. Its pharmacodynamic properties are mainly influenced by its interaction with beta-lactam antibiotics, enhancing their efficacy in treating infections. The overall effect is a synergistic relationship that increases the potency of the antibiotic treatment.

Pharmacokinetics

Clavulanate is usually administered orally or parenterally, and it is rapidly absorbed from the gastrointestinal tract. It reaches peak plasma concentrations within 1 to 2 hours after administration. The drug is widely distributed in body tissues, with a volume of distribution indicative of good tissue penetration. Clavulanate undergoes hepatic metabolism, primarily by conjugation, and is excreted largely in the urine as metabolites. The elimination half-life is approximately 1 hour, necessitating frequent dosing for optimal therapeutic effect.

Contra-indications

• Hypersensitivity to clavulanate or any component of the formulation
• History of jaundice or hepatic impairment related to previous use of beta-lactam antibiotics

Adverse effects

• Diarrhea
• Nausea
• Vomiting
• Rash
• Hepatic dysfunction
• Allergic reactions

Interactions

• Probenecid may increase concentrations of clavulanate
• Anticoagulants may have altered effects due to changes in gut flora

Precautions

• Monitor liver function during prolonged therapy
• Use cautiously in patients with renal impairment
• Assess for history of allergy to penicillins or cephalosporins

Pregnancy

Clavulanate is classified as category B. Animal studies have not shown teratogenic effects, but adequate and well-controlled studies in pregnant women are lacking.

Breast-feeding

Clavulanate is excreted in breast milk. Caution is advised when administering to nursing mothers.

Storage

Store in a cool, dry place away from direct light. Keep out of reach of children.

Formulations

• Clavulanate potassium 125 mg/5 mL
• Clavulanate potassium 250 mg/5 mL