REDMOXY 250 DT

Indications

• Bacterial infections
• Respiratory tract infections
• Urinary tract infections
• Skin and soft tissue infections
• Otitis media
• Sinusitis
• Helicobacter pylori eradication

Dosage

Children: Refer to BNF for Children for specific dosing guidelines.

Adults: Refer to BNF for specific dosing guidelines.

Mechanism of action

Amoxicillin works by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs) located inside the bacterial cell wall, inhibiting the transpeptidation enzyme required for cross-linking peptidoglycan layers. This action compromises the integrity of the bacterial cell wall, leading to cell lysis and death, particularly in actively dividing bacteria.

Pharmacodynamics

Amoxicillin exhibits bactericidal activity, meaning it kills bacteria rather than merely inhibiting their growth. Its effectiveness is influenced by the time that the drug concentration remains above the minimum inhibitory concentration (MIC) of the target bacteria. Resistance can occur through the production of beta-lactamase enzymes by certain bacteria, which hydrolyze the beta-lactam ring of the antibiotic, rendering it ineffective.

Pharmacokinetics

Amoxicillin is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 1 to 2 hours after oral administration. It has a bioavailability of about 70-90%. The drug is widely distributed throughout body tissues and fluids, including the lungs, liver, and bile. It is partially metabolized in the liver, and approximately 50-70% of the dose is excreted unchanged in the urine. The elimination half-life ranges from 1 to 1.5 hours, and renal function significantly affects clearance.

Contra-indications

• Hypersensitivity to amoxycillin or other penicillins
• History of severe allergic reactions (e.g., anaphylaxis) to any penicillin
• Infectious mononucleosis (increased risk of rash)

Adverse effects

• Diarrhea
• Nausea
• Vomiting
• Rash
• Allergic reactions (e.g., urticaria, anaphylaxis)
• Hepatic dysfunction (elevated liver enzymes)
• Renal impairment
• Superinfection (e.g., Clostridium difficile-associated diarrhea)

Interactions

• Probenecid (increases amoxycillin levels by reducing renal clearance)
• Methotrexate (increased toxicity due to reduced clearance)
• Other antibiotics (e.g., tetracyclines may interfere with the bactericidal effect)
• Oral contraceptives (possible reduced efficacy although evidence is inconclusive)

Precautions

• Renal impairment (dose adjustment may be necessary)
• History of gastrointestinal disease (e.g., colitis)
• Use with caution in patients with a history of allergies
• Monitor for signs of anaphylaxis after the first dose

Pregnancy

Amoxycillin is commonly considered safe to use during pregnancy, but it should only be prescribed if clearly needed and after assessing the benefits versus risks.

Breast-feeding

Amoxycillin is excreted in breast milk, but it is generally considered safe for use while breastfeeding. Monitoring for potential adverse effects in the infant is recommended.

Storage

Store in a cool, dry place away from direct light. Reconstituted solutions should be refrigerated and used within a specified time frame, usually 7 to 14 days depending on the formulation.

Formulations

• Oral tablets (250 mg, 500 mg, 1000 mg)
• Oral suspension (125 mg/5 mL, 250 mg/5 mL)
• Injectable forms (e.g., amoxycillin sodium)