Moxarin (Amoxicillin)

Amoxicillin is used to treat bacterial infections of the respiratory and urinary tracts.

• Upper respiratory tract infections: Reduces bacterial load and improves cough, fever and sore throat.
• Otitis media: Clears middle‑ear infection, relieving pain and inflammation.
• Sinusitis: Resolves bacterial sinus infection, easing congestion and facial pressure.
• Community‑acquired pneumonia: Eradicates causative bacteria, supporting recovery of lung function.
• Urinary tract infections: Eliminates common uropathogens, alleviating dysuria and frequency.

• Amoxicillin exerts its antibacterial effect by binding to penicillin‑binding proteins (PBPs) located on the bacterial cell wall. This binding inhibits the transpeptidation step of peptidoglycan synthesis, weakening the cell wall and leading to osmotic lysis of susceptible Gram‑positive and selected Gram‑negative organisms. The drug is stable in the acidic gastric environment, allowing oral absorption, and is primarily excreted unchanged in the urine, which contributes to its efficacy in urinary tract infections.

Amoxicillin may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Nausea: mild gastrointestinal upset, often transient.
• Diarrhea: loose stools, may be self‑limiting.
• Rash: mild skin erythema or itching.
• Headache: transient cranial discomfort.
• Vomiting: occasional emesis, usually mild.
• Taste disturbance: altered taste perception, usually temporary.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction with airway compromise and hypotension.
• Stevens‑Johnson syndrome: rare mucocutaneous blistering disorder with skin detachment.
• Clostridioides difficile colitis: severe diarrhea due to bacterial overgrowth.
• Hepatotoxicity: elevated liver enzymes or jaundice indicating liver injury.
• Hemolytic anemia: immune‑mediated red cell destruction leading to fatigue.
• Serum sickness‑like reaction: fever, arthralgia, rash occurring weeks after therapy.

When prescribing amoxicillin, several safety considerations should be observed.

• Assess allergy: verify no known penicillin hypersensitivity before prescribing.
• Adjust renal function: modify dose in patients with impaired kidney function.
• Monitor liver: check hepatic enzymes during prolonged therapy.
• Use caution in pregnancy: consider risk‑benefit as safety data are limited.
• Review concomitant medications: check for potential drug interactions.
• Store below 25°C: keep in the original pack, protect from moisture.

Amoxicillin can interact with other medicines, requiring attention to avoid reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Probenecid: reduces renal excretion, increasing amoxicillin plasma levels.
• Methotrexate: may increase toxicity due to reduced clearance.
• Oral contraceptives: may have reduced efficacy, advise additional contraception.

Moderate Interactions (Monitor Closely)

• Warfarin: may enhance anticoagulant effect, monitor INR.
• Allopurinol: possible rash, monitor skin reactions.
• Tetracyclines: antagonistic effect on bacterial killing, avoid concurrent use.
• Other oral anticoagulants: may require dose adjustment.