AMOXICILLIN (a-mox-i-sill'in) Amoxil, Apo-Amoxi , Larotid, Novamoxin, Polymox, Sumox, Trimox, Utimox, Wymox, DisperMox Classifications: antiinfective; antibiotic; aminopenicillin Prototype: Ampicillin Pregnancy Category: B

Availability

125 mg, 250 mg, 500 mg tablets; 250 mg, 500 mg capsules; 50 mg/mL, 125 mg/5 mL, 250 mg/5 mL powder for suspension; 200 mg, 400 mg, 600 mg dispersible tablets

Actions

Broad-spectrum, acid-stable, semisynthetic aminopenicillin and analogue of ampicillin. Acts by inhibiting mucoprotein synthesis in cell wall of rapidly multiplying bacteria. It is bactericidal and is inactivated by penicillinase.

Therapeutic Effects

Active against both aerobic gram positive and aerobic gram negative bacteria including: Enterococcus faecalis, Streptococcus pneumonia, Escherichia coli, Haemophilus influenzae, Helicobacter pylori.

Uses

Infections of ear, nose, throat, GU tract, skin, and soft tissue caused by susceptible bacteria. Also used in uncomplicated gonorrhea. Available in combination with potassium clavulanate, which extends antibacterial spectrum of amoxicillin to include beta-lactamase-producing strains.

Contraindications

Hypersensitivity to penicillins; infectious mononucleosis.

Cautious Use

History of or suspected atopy or allergy (hives, eczema, hay fever, asthma); history of cephalosporin or carbapenem hypersensitivity; colitis, dialysis, diarrhea, GI disease; infants, neonates; viral infection, syphilis, renal impairment or failure, diabetes mellitus, leukemia, pregnancy (category B), or lactation.

Route & Dosage

Mild to Moderate Infections Adult: PO 250–500 mg q8h Child: PO 25–50 mg/kg/d (max: 60–80 mg/kg/d) divided q8h or 200–400 mg q12h Gonorrhea Adult: PO 3 g as single dose with 1 g probenecid Child: PO 2 y, 50 mg/kg as single dose with probenecid 25 mg/kg

Administration

• Ensure that chewable tablets are chewed or crushed before being swallowed with a liquid.
• Place reconstituted pediatric drops directly on child's tongue or add to formula, milk, fruit juice, water, ginger ale, or other soft drink. Have child drink all the prepared dose promptly.
• Store in tightly covered containers at 15°–30° C (59°–86° F) unless otherwise directed. Reconstituted oral suspensions are stable for 7 d at room temperature.

Adverse Effects (1%)

Interactions

Pharmacokinetics

Nursing Implications

Assessment & Drug Effects

• Determine previous hypersensitivity reactions to penicillins, cephalosporins, and other allergens prior to therapy.
• Lab tests: Baseline C&S tests prior to initiation of therapy, start drug pending results; periodic assessments of renal, hepatic, and hematologic functions should be made during prolonged therapy.
• Monitor for S&S of an urticarial rash (usually occurring within a few days after start of drug) suggestive of a hypersensitivity reaction. If it occurs, look for other signs of hypersensitivity (fever, wheezing, generalized itching, dyspnea), and report to physician immediately.
• Report onset of generalized, erythematous, maculopapular rash (ampicillin rash) to physician. Ampicillin rash is not due to hypersensitivity; however, hypersensitivity should be ruled out.
• Closely monitor diarrhea to rule out pseudomembranous colitis.

Patient & Family Education

• Take drug around the clock, do not miss a dose, and continue therapy until all medication is taken, unless otherwise directed by physician.
• Report onset of diarrhea and other possible symptoms of superinfection to physician (see Appendix F).
• Do not breast feed while taking this drug without consulting physician.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug