amoxicillin trihydrate

Drug Name

Generic Name:  amoxicillin trihydrate

Brand Name: Amoxil, Amoxil Pediatric Drops, Apo-Amoxi (CAN), DisperMox, Novamoxin (CAN), Nu-Amoxi (CAN), Trimox

Classification: Antibiotic (penicillin–ampicillin type)

Pregnancy Category B

Dosage & route

ADULTS AND PEDIATRIC PATIENTS > 40 KG

  • URIs, GU infections, skin and soft-tissue infections: 250–500 mg PO q 8 hr or 875 mg PO bid.
  • Postexposure anthrax prophylaxis: 500 mg PO tid.
  • Lower respiratory infections: 500 mg PO q 8 hr or 875 mg PO bid.
  • Uncomplicated gonococcal infections: 3 g amoxicillin with 1 g probenecid PO.
  • C. trachomatis in pregnancy: 500 mg PO tid for 7 days or 875 mg PO bid.
  • Prevention of SBE in dental, oral, or upper respiratory procedures: 2 g 1 hr before procedure.
  • Prevention of SBE in GI or GU procedures: 2 g ampicillin plus 1.5 mg/kg gentamicin IM or IV 30 min before procedure, followed by 1 g amoxicillin; for low-risk patients, 2 g 1 hr before procedure.
  • H. pylori infections: 1 g bid with clarithromycin 500 mg bid and lansoprazole 30 mg bid for 14 days.

PEDIATRIC PATIENTS < 40 KG

  • URIs, GU infections, skin, and soft-tissue infections: 20–40 mg/kg/day PO in divided doses q 8 hr.
  • Post-exposure anthrax prophylaxis: 80 mg/kg/day PO divided into 3 doses.
  • Prevention of SBE in dental, oral, or upper respiratory procedures: 50 mg/kg 1 hr before procedure.
  • Prevention of SBE in GI or GU procedures: 50 mg/kg ampicillin plus 2 mg/kg gentamicin IM or IV 30 min before procedure followed by 25 mg/kg amoxicillin. For moderate-risk patients, 50 mg/kg PO 1 hr before procedure.

PEDIATRIC PATIENTS > 3 MO

  • Mild to moderate URIs, GU infections, and skin infections: 20 mg/kg daily in divided doses q 8 hr or 25 mg/kg in divided doses q 12 hr.
  • For lower respiratory infections, or severe URIs, GU, or skin infections: 40 mg/kg daily in divided doses q 8 hr or 45 mg/kg daily in divided doses q 12 hr.

PEDIATRIC PATIENTS < 12 WK

  • Up to 30 mg/kg daily in divided doses q 12 hr.
Therapeutic actions
  • Bactericidal: Inhibits synthesis of cell wall of sensitive organisms, causing cell death.
Indications
  • Infections due to susceptible strains of Haemophilus influenzae, Escherichia coli, Proteus mirabilis, Neisseria gonorrhoeae, Streptococcus pneumoniae, Enterococcus faecalis, streptococci, non–penicillinase-producing staphylococci
  • Helicobacter pylori infection in combination with other agents
  • Postexposure prophylaxis against Bacillus anthracis
  • Unlabeled use: Chlamydia trachomatis in pregnancy
Adverse effects
  • CNS: Lethargy, hallucinations, seizures
  • GI: Glossitis, stomatitis, gastritis, sore mouth, furry tongue, black “hairy” tongue, nausea, vomiting, diarrhea, abdominal pain, bloody diarrhea, enterocolitis, pseudomembranous colitis, nonspecific hepatitis
  • GU: Nephritis
  • Hematologic: Anemia, thrombocytopenia, leukopenia, neutropenia, prolonged bleeding time
  • Hypersensitivity: Rash, fever, wheezing, anaphylaxis
  • Other: Superinfections—oral and rectal moniliasis, vaginitis
Contraindications
  • Contraindicated with allergies to penicillins, cephalosporins, or other allergens.
  • Use cautiously with renal disorders, lactation.
Nursing considerations
Assessment
  • History: Allergies to penicillins, cephalosporins, or other allergens; renal disorders; lactation
  • Physical: Culture infected area; skin color, lesion; R, adventitious sounds; bowel sounds; CBC, LFTs, renal function tests, serum electrolytes, Hct, urinalysis
Interventions
  • Culture infected area prior to treatment; reculture area if response is not as expected.
  • Give in oral preparations only; amoxicillin is not affected by food.
  • Continue therapy for at least 2 days after signs of infection have disappeared; continuation for 10 full days is recommended.
  • Use corticosteroids, antihistamines for skin reactions.
Teaching points
  • Take this drug around-the-clock.
  • Take the full course of therapy; do not stop because you feel better.
  • This antibiotic is specific for this problem and should not be used to self-treat other infections.
  • You may experience these side effects: Nausea, vomiting, GI upset (eat frequent small meals); diarrhea; sore mouth (frequent mouth care may help).
  • Report unusual bleeding or bruising, sore throat, fever, rash, hives, severe diarrhea, difficulty breathing.