NEOMYCIN SULFATE
(nee-oh-mye'sin)
Mycifradin, Myciguent, Neo-Tabs, Neo-fradin
Classifications: antiinfective; aminoglycoside antibiotic
Prototype: Gentamicin
Pregnancy Category: D

Availability

500 mg tablet; 125 mg/5 mL oral solution; 3.5 mg/g ointment, cream

Actions

Aminoglycoside antibiotic obtained from Streptomyces fradiae; reported to be the most potent in neuromuscular blocking action and the most toxic of this group.

Therapeutic Effects

Active against a wide variety of gram-negative bacteria, including Citrobacter, Escherichia coli, Enterobacter, Klebsiella, Proteus (including indole-positive and indole-negative strains), Pseudomonas aeruginosa, and Serratia sp. Also effective against certain gram-positive organisms, particularly, penicillin-sensitive and some methicillin-resistant strains of Staphylococcus aureus (MRSA).

Uses

Severe diarrhea caused by enteropathogenic Escherichia coli; preoperative intestinal antisepsis; to inhibit nitrogen-forming bacteria of GI tract in patients with cirrhosis or hepatic coma and for urinary tract infections caused by susceptible organisms. Also topically for short-term treatment of eye, ear, and skin infections. Available in a variety of creams, ointments, and sprays in combination with other antibiotics and corticosteroids.

Contraindications

Use of oral drug in patients with intestinal obstruction; ulcerative bowel lesions; topical applications over large skin areas; parenteral use in patients with kidney disease or impaired hearing; parkinsonism; myasthenia gravis; pregnancy (category D), lactation.

Cautious Use

Topical otic applications in patients with perforated eardrum, children.

Route & Dosage

Intestinal Antisepsis
Adult: PO 1 g q1h times 4 doses, then 1 g q4h times 5 doses
Child: PO 10.3 mg/kg q4–6h for 3 d

Hepatic Coma
Adult: PO 4–12 g/d in 4 divided doses for 5–6 d
Child: PO 437.5–1225 mg/m² q6h for 5–6 d

Diarrhea
Adult: PO 50 mg/kg in 4 divided doses for 2–3 d IM 1.3–2.6 mg/kg q6h
Child: PO 8.75 mg/kg q6h for 2–3 d

Cutaneous Infections
Adult: Topical Apply 1–3 times/d

Administration

Oral

Preoperative bowel preparation: Saline laxative is generally given immediately before neomycin therapy is initiated.

Topical

Consult physician about what to use for cleansing skin before each application.
Make sure ear canal is clean and dry prior to instillation for topical therapy of external ear.

Adverse Effects (1%)

Body as a Whole: Neuromuscular blockade with muscular and respiratory paralysis; hypersensitivity reactions. GI: Mild laxative effect, diarrhea, nausea, vomiting; prolonged therapy: malabsorption-like syndrome including cyanocobalamin (vitamin B₁₂) deficiency, low serum cholesterol. Urogenital: Nephrotoxicity. Special Senses: Ototoxicity. Skin: Redness, scaling, pruritus, dermatitis.

Interactions

Drug: May decrease absorption of cyanocobalamin.

Pharmacokinetics

Absorption: 3% absorbed from GI tract in adults; up to 10% absorbed in neonates. Peak: 1–4 h. Elimination: 97% excreted unchanged in feces. Half-Life: 3 h.

Nursing Implications

Assessment & Drug Effects

Perform audiometric studies twice weekly in patients with kidney or liver dysfunction receiving extended oral therapy.
Lab tests: Obtain baseline and daily urinalysis for albumin, casts, and cells; and BUN every other day. Also, serum drug levels (toxic levels reportedly range from 8 to 30 mcg/mL, although individual variations exist).
Monitor I&O in patients receiving oral or parenteral therapy. Report oliguria or changes in I&O ratio. Inadequate neomycin excretion results in high serum drug levels and risk of nephrotoxicity and ototoxicity.

Patient & Family Education

Stop treatment and consult your physician if irritation occurs when you are using topical neomycin. Allergic dermatitis is common.
Report any unusual symptom related to ears or hearing (e.g., tinnitus, roaring sounds, loss of hearing acuity, dizziness).
Do not exceed prescribed dosage or duration of therapy.
Do not breast feed while taking this drug.

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