NEOMYCIN SULFATE

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

Availability

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

Action

Aminoglycoside antibiotic obtained from Streptomyces fradiae. It inhibits bacterial protein synthesis through irreversible binding to the 30S ribosomal subunit within susceptible bacteria. Causes bacteria not to replicate.

Therapeutic Effect

Active against a wide variety of gram-negative bacteria. 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.

Contraindications

Use of oral drug in patients with intestinal obstruction; ulcerative bowel lesions; topical applications over large skin areas; hypersensitivity to aminoglycosides; parkinsonism; myasthenia gravis; pregnancy (category C), lactation.

Cautious Use

Topical otic applications in patients with perforated eardrum, children; dehydration; renal disease, renal impairment.

Route & Dosage

Intestinal Antisepsis Adult: PO 1 g q1h x 4 doses, then 1 g q4h x 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.

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