neomycin sulfate

neomycin sulfate

[ne′ō-mī′sin]

an aminoglycoside antibiotic.

indications It is prescribed orally to treat hepatic coma and infections of the intestine and to prepare the gastrointestinal tract for surgery. It is prescribed topically to treat skin infections.

contraindications Renal dysfunction, intestinal obstruction, or known hypersensitivity to this drug or to any aminoglycoside medication prohibits its use. Neomycin is not administered parenterally.

adverse effects Among the more serious adverse effects are nausea, vomiting, diarrhea, malabsorption, or superinfection. Prolonged treatment in patients with impaired renal function may result in the toxicities of systemic aminoglycosides (e.g., ototoxicity, nephrotoxicity, neuromuscular toxicity). Hypersensitivity reactions may occur with topical administration of this drug.

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neomycin sulfate (topical),

n brand name: Myciguent;
drug class: local antibacterial;
action: interferes with bacterial protein synthesis;
use: skin infections.

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neomycin sulfate

A broad-spectrum antibiotic agent effective against gram-negative and gram-positive organisms, although it is not effective against Pseudomonas aeruginosa. It may be applied topically as eyedrops or eye ointment, but it is most commonly combined with bacitracin and polymyxin B. Syn. framycetin (a mixture of neomycin A, neomycin B and neomycin C).

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neomycin sulfate

Neo-Fradin, Nivemycin (UK)

Pharmacologic class: Aminoglycoside

Therapeutic class: Anti-infective

Pregnancy risk category D

FDA Boxed Warning

• Systemic absorption follows oral use and may lead to toxic reactions. Observe patient closely for indications of toxicity. Neurotoxicity (including ototoxicity) and nephrotoxicity have occurred, even at recommended doses. Perform serial, vestibular, and audiometric tests as well as renal function tests, especially in high-risk patients. Risk of nephrotoxicity and ototoxicity is greater in patients with renal impairment. Ototoxicity may be delayed, and patients developing cochlear damage won't have symptoms during therapy; total or partial deafness may occur long after drug is stopped
• Neuromuscular blockage and respiratory paralysis may follow oral use. Consider these risks, especially to patients receiving anesthetics or neuromuscular blockers (such as tubocurarine, succinylcholine, and decamethonium) and those receiving massive transfusions of citrated anticoagulated blood. If blockage occurs, calcium salts may reverse these phenomena, but patient may need mechanical respiratory assistance.
• Avoid concurrent or sequential systemic, oral, or topical use of other aminoglycosides or neurotoxic drugs, as toxicity may be additive.
• Advanced age and dehydration increase risk of toxicity.
• Avoid giving drug concurrently with potent diuretics, as some diuretics are ototoxic. Also, I.V. diuretics may enhance neomycin toxicity by altering its blood and tissue levels.

Action

Interferes with bacterial protein synthesis by binding to 30S ribosomal subunit, causing misreading of genetic code. Inaccurate peptide sequence then forms in protein chain, causing bacterial death.

Availability

Ointment: 0.5%

Oral solution: 125 mg/5 ml

Tablets: 500 mg

⊘Indications and dosages

➣ Preoperative intestinal antisepsis

Adults: 1 g P.O. q hour for four doses, then 1 g q 4 hours for 24 hours or 1 g at 19 hours, 18 hours, and 9 hours before surgery

➣ Hepatic encephalopathy

Adults: 4 to 12 g/day P.O. in divided doses

➣ Superficial bacterial infections

Adults: Apply ointment topically one to five times daily.

Contraindications

• Hypersensitivity to drug or other aminoglycosides
• Intestinal obstruction

Precautions

Use cautiously in:
• renal impairment, neuromuscular diseases (such as myasthenia gravis), hearing impairment
• obese patients
• elderly patients
• pregnant or breastfeeding patients
• children under age 18 (safety not established).

Administration

• Give preoperative dose before bowel surgery, after cathartic administration, as ordered.

Route	Onset	Peak	Duration
P.O.	Variable	1-4 hr	Unknown
Topical	Unknown	Unknown	Unknown

Adverse reactions

CNS: neuromuscular blockade

EENT: ototoxicity (with prolonged, high-dose use)

GI: nausea, vomiting, diarrhea, malabsorption syndrome

GU: nephrotoxicity (with prolonged, high-dose use)

Other: superinfection

Interactions

Drug-drug. Acyclovir, amphotericin B, cephalosporin, cisplatin, other aminoglycosides, vancomycin: increased risk of ototoxicity and nephrotoxicity

Digoxin: decreased digoxin absorption

Dimenhydrinate: masking of ototoxicity symptoms

Oral anticoagulants: increased anticoagulant effect

Potent loop diuretics: increased risk of ototoxicity

Patient monitoring

• Assess for neuromuscular blockade, ototoxicity, and nephrotoxicity.
• Monitor kidney function tests.

Patient teaching

• Instruct patient to drink plenty of water.
• Tell patient to complete full course of therapy.
• Inform patient that drug may cause muscle weakness.
• Instruct patient to report hearing problems and change in urination pattern.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects neuromuscular status.
• Tell patient he'll undergo frequent blood testing during therapy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs mentioned above.