Antif

• Approved Indications:
• Respiratory tract infections: acute otitis media, pharyngitis, tonsillitis, sinusitis, bronchitis, and community-acquired pneumonia caused by susceptible bacteria.
• Genitourinary tract infections: cystitis, pyelonephritis, and uncomplicated gonorrhea.
• Skin and soft tissue infections including cellulitis and abscesses.
• Helicobacter pylori infection (as part of combination therapy).
• Dental infections and prophylaxis for bacterial endocarditis.
• Gastrointestinal infections caused by susceptible organisms.
• Off-label Uses:
• Early Lyme disease.
• Prophylaxis against bacterial infections in immunocompromised patients.

• Route: Oral.
• Adults:
• 250–500 mg every 8 hours, or 500–875 mg every 12 hours depending on infection severity.
• Severe infections may require up to 1 g every 8 hours.
• Pediatrics:
• 20–40 mg/kg/day divided every 8 hours or 25–45 mg/kg/day divided every 12 hours, adjusted by infection severity.
• Elderly:
• No adjustment needed unless renal impairment exists.
• Renal Impairment:
• Mild to moderate impairment: no adjustment generally needed.
• Severe impairment (CrCl <30 mL/min): dose reduction or extended dosing interval required.
• Hepatic Impairment:
• Use with caution; no specific dose adjustment.
• Duration: 5 to 14 days based on infection type and clinical response.

Amoxicillin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), preventing cross-linking of peptidoglycan chains essential for cell wall integrity. This results in bacterial cell lysis and death. It is bactericidal against susceptible Gram-positive and some Gram-negative bacteria.

• Absorption: Well absorbed orally; bioavailability 75–90%.
• Distribution: Widely distributed in body fluids and tissues including middle ear, sputum, and bile; crosses placenta and appears in breast milk.
• Metabolism: Minimal hepatic metabolism.
• Half-life: Approximately 1 hour in healthy adults.
• Elimination: Primarily renal excretion via active tubular secretion and glomerular filtration.

• Pregnancy: FDA Category B; no proven risk in humans but use only if clearly indicated.
• Lactation: Excreted in breast milk in low concentrations; generally considered safe; monitor infant for adverse effects.

• Beta-lactam antibiotic; Penicillin subclass.

• Hypersensitivity to amoxicillin, penicillin, or any beta-lactam antibiotics.
• History of severe allergic reactions to beta-lactams.

• Risk of hypersensitivity reactions including anaphylaxis; monitor closely.
• Use cautiously in renal impairment; adjust dose accordingly.
• Monitor for signs of Clostridioides difficile-associated diarrhea.
• Prolonged use may result in superinfections with resistant organisms.

• Common: Diarrhea, nausea, vomiting, rash, urticaria.
• Rare/Serious: Anaphylaxis, Stevens-Johnson syndrome, toxic epidermal necrolysis, hemolytic anemia, hepatic dysfunction.

• Probenecid increases amoxicillin plasma levels by inhibiting renal excretion.
• May reduce efficacy of oral contraceptives.
• Increased risk of rash with concurrent allopurinol.
• Potential increased anticoagulant effect with warfarin; monitor INR.
• May enhance methotrexate toxicity.

• Remains first-line for many common bacterial infections including otitis media and sinusitis.
• Emphasis on antimicrobial stewardship to prevent resistance.
• Updated dosing for certain infections per latest clinical guidelines.

• Store at 20°C to 25°C (68°F to 77°F), protected from moisture and light.
• Keep tablets in tight containers.
• Reconstituted suspensions require refrigeration (2°C to 8°C) and must be used within 7–10 days.
• Do not freeze liquid forms.