Class: β-Lactam Antibiotic
Dosage Forms. Capsule: 250 mg, 500 mg; Chewable Tablet: 125 mg, 200 mg, 250 mg, 400 mg; Drop: 50 mg/mL; Suspension: 125 mg/mL, 250 mg/mL; Tablet: 500 mg, 875 mg; Tablet, Extended Release: 775 mg
Common FDA Label Indication, Dosing and Titration.
1. Acute otitis media: Adults, 500-875 mg po q12h × 10 d; Children, 80-90 mg/kg/d po in 2-3 divided doses
2. Lower respiratory tract infection: Adults, 1 g po tid × 10 d; Children, 45 mg/kg/d divided q12h
3. Pharyngitis, tonsillitis: Adults and Children over 12 y: 775 mg po daily × 10 d
4. Streptococcal pharyngitis: Adults, 1 g po daily × 10 d; Children, 50 mg/kg po once daily for 10 d, max 1 g daily
5. Ear, nose, and throat infection, infection of skin and/or subcutaneous tissue, infection of genitourinary system: Adults, 500-875 mg po q12h × 10 d; Children, 25-45 mg/kg/d po divided q12h
6. Helicobacter pylori gastrointestinal tract infection: 1 g po bid with PPI
1. Bacterial endocarditis, prophylaxis: Adults, 2 g po 1 h before procedure; Children, 50 mg/kg po 1 h prior to procedure, max 2 g daily
2. Lyme disease: 500 mg po tid × 14-21 d; Children: 50 mg/kg/d po in 3 divided doses × 14-21 d
MOA. Semisynthetic penicillin derivative that inhibits the biosynthesis of bacterial cell wall mucopeptide. Typically active against Streptococcus, Enterococcus, Staphylococcus, and Enterobacteriaceae.
Drug Characteristics: Amoxicillin
Medication Safety Issues: Amoxicillin
Drug Interactions: Amoxicillin
Adverse Reactions: Amoxicillin
Efficacy Monitoring Parameters. Resolution of clinical signs of infection.
Toxicity Monitoring Parameters. Severe diarrhea, dark urine, yellowing of skin or eye, unusual bruising or bleeding, blistering skin rash, or shortness of breath.
Key Patient Counseling Points. Complete full course of therapy. For the suspension, shake well and store in the refrigerator. Note short expiration after reconstitution. Avoid mixing suspension with food or beverages, but food can be taken afterward. Symptoms should improve within 2-3 d; if they worsen, seek follow-up with healthcare practitioner.
Clinical Pearls. There is cross hypersensitivity between penicillin and cephalosporins; use with caution in cephalosporin allergic. May resume normal activities after 24 h of antibiotics if afebrile. Extended-release tablet not approved for children <12 y of age.