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amoxicillin trihydrate (amoxycillin trihydrate)
Alphamox‡, Amoxil, Apo-Amoxi†, Cilamox‡, Moxacin‡, Novamoxin†, Nu-Amoxi†, Trimox

Pregnancy Risk Category B

How supplied
Tablets (chewable):
125 mg, 250 mg
Capsules:
250 mg, 500 mg
Oral suspension:
50 mg/ml (pediatric drops), 125 mg/5 ml, 250 mg/5 ml (after reconstitution)

Action
An aminopenicillin that inhibits cell-wall synthesis during bacterial multiplication. Bacteria resist amoxicillin by producing penicillinases-enzymes that hydrolyze amoxicillin.

Indications & dosage
Systemic infections, acute and chronic urinary tract infections due to susceptible strains of gram-positive and gram-negative organisms
-
Adults and children weighing 20 kg (44 lb) or over:
250 to 500 mg P.O. q 8 hours.
Children weighing under 20 kg:
20 mg/
kg P.O. daily in divided doses q 8 hours; in severe infection, 40 mg/kg P.O. daily in divided doses q 8 hours or 500 mg to 1 g/m2 P.O. in divided doses q 8 hours.
Uncomplicated gonorrhea-

Adults and children weighing over 45 kg (99 lb):
3 g P.O. with 1 g probenecid given as a single dose.
Children ages 2 and older weighing under 45 kg:
50 mg/kg (maximum of 3 g) P.O. with 25 mg/kg (up to 1 g) of probenecid as a single dose. Don't give probenecid to children under age 2.
Endocarditis prophylaxis for dental and GI/GU procedures
-
Adults:
2 g P.O. 1 hour before procedure.
Children:
50 mg/kg P.O. 1 hour before procedure.

Adverse reactions
CNS:
lethargy, hallucinations, seizures, anxiety, confusion, agitation, depression, dizziness, fatigue.
GI:
nausea, vomiting, diarrhea, glossitis, stomatitis, gastritis, abdominal pain, enterocolitis, pseudomembranous colitis, black "hairy" tongue.
GU:
interstitial nephritis, nephropathy, vaginitis.
Hematologic:
anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, leukopenia, hemolytic anemia, agranulocytosis.
Other:
hypersensitivity reactions, anaphylaxis, overgrowth of nonsusceptible organisms.

Interactions
Drug-drug.
Allopurinol: increased incidence of rash. Monitor patient.
Oral contraceptives:
efficacy of oral contraceptives may be decreased. Recommend additional form of contraception during penicillin therapy.
Probenecid:
increased blood levels of amoxicillin and other penicillins. Probenecid may be used for this purpose.

Effects on diagnostic tests
Amoxicillin may alter results of urine glucose tests that use cupric sulfate (Benedict's reagent or Clinitest). Make urine glucose determinations with glucose oxidase methods (Diastix or Chemstrip uG). Amoxicillin may falsely cause a positive Coombs' test.

Contraindications
Contraindicated in patients with hypersensitivity to drug or other penicillins.

Nursing considerations

Patient teaching

*Liquid contains alcohol. **May contain tartrazine.  †Canada  ‡Australia  §U.K.  OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING

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