Boxed Warning

SYSTEMIC ABSORPTION OF NEOMYCIN OCCURS FOLLOWING ORAL ADMINISTRATION AND TOXIC REACTIONS MAY OCCUR. Patients treated with neomycin should be under close clinical observation because of the potential toxicity associated with their use. NEUROTOXICITY (INCLUDING OTOTOXICITY) AND NEPHROTOXICITY FOLLOWING THE ORAL USE OF NEOMYCIN SULFATE HAVE BEEN REPORTED, EVEN WHEN USED IN RECOMMENDED DOSES. THE POTENTIAL FOR NEPHROTOXICITY, PERMANENT BILATERAL AUDITORY OTOTOXICITY AND SOMETIMES VESTIBULAR TOXICITY IS PRESENT IN PATIENTS WITH NORMAL RENAL FUNCTION WHEN TREATED WITH HIGHER DOSES OF NEOMYCIN AND/OR FOR LONGER PERIODS THAN RECOMMENDED. Serial, vestibular and audiometric tests, as well as tests of renal function, should be performed (especially in high-risk patients). THE RISK OF NEPHROTOXICITY AND OTOTOXICITY IS GREATER IN PATIENTS WITH IMPAIRED RENAL FUNCTION. Ototoxicity is often delayed in onset and patients developing cochlear damage will not have symptoms during therapy to warn them of developing eighth nerve destruction and total or partial deafness may occur long after neomycin has been discontinued.

Neuromuscular blockage and respiratory paralysis have been reported following the oral use of neomycin. The possibility of the occurrence of neuromuscular blockage and respiratory paralysis should be considered if neomycin is administered, especially to patients receiving anesthetics, neuromuscular blocking agents such as tubocurarine, succinylcholine, decamethonium, or in patients receiving massive transfusions of citrate anticoagulated blood. If blockage occurs, calcium salts may reverse these phenomena but mechanical respiratory assistance may be necessary.

Concurrent and/or sequential systemic, oral or topical use of other aminoglycosides, including paromomycin and other potentially nephrotoxic and/or neurotoxic drugs such as bacitracin, cisplatin, vancomycin, amphotericin B, polymyxin B, colistin and viomycin, should be avoided because the toxicity may be additive.

Other factors which increase the risk of toxicity are advanced age and dehydration.

The concurrent use of neomycin with potent diuretics such as ethacrynic acid or furosemide should be avoided, since certain diuretics by themselves may cause ototoxicity. In addition, when administered intravenously, diuretics may enhance neomycin toxicity by altering the antibiotic concentration in serum and tissue.

Indications and Usage

To reduce the development of drug-resistant bacteria and maintain the effectiveness of neomycin sulfate tablets and other antibacterial drugs, neomycin sulfate tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Suppression of Intestinal Bacteria

Neomycin sulfate tablets are indicated as adjunctive therapy as part of a regimen for the suppression of the normal bacterial flora of the bowel, e.g., preoperative preparation of the bowel. It is given concomitantly with erythromycin enteric-coated base (see DOSAGE AND ADMINISTRATION ).

Hepatic Coma (Portal-Systemic Encephalopathy)

Neomycin sulfate has been shown to be effective adjunctive therapy in hepatic coma by reduction of the ammonia-forming bacteria in the intestinal tract. The subsequent reduction in blood ammonia has resulted in neurologic improvement.

Dosage and Administration

To minimize the risk of toxicity, use the lowest possible dose and the shortest possible treatment period to control the condition. Treatment for periods longer than two weeks is not recommended.

Hepatic Coma

For use as an adjunct in the management of hepatic coma, the recommended dose is 4 to 12 grams per day given in the following regimen:

Withdraw protein from diet. Avoid use of diuretic agents.
Give supportive therapy, including blood products, as indicated.
Give neomycin sulfate tablets in doses of 4 to 12 grams of neomycin sulfate per day (eight to 24 tablets) in divided doses. Treatment should be continued over a period of five to six days, during which time protein should be returned incrementally to the diet.
If less potentially toxic drugs cannot be used for chronic hepatic insufficiency, neomycin in doses of up to four grams daily (eight tablets per day) may be necessary. The risk for the development of neomycin-induced toxicity progressively increases when treatment must be extended to preserve the life of a patient with hepatic encephalopathy who has failed to fully respond. Frequent periodic monitoring of these patients to ascertain the presence of drug toxicity is mandatory (see PRECAUTIONS ). Also, neomycin serum concentrations should be monitored to avoid potentially toxic levels. The benefits to the patient should be weighed against the risks of nephrotoxicity, permanent ototoxicity and neuromuscular blockade following the accumulation of neomycin in the tissues.

Preoperative Prophylaxis for Elective Colorectal Surgery.

Listed below is an example of a recommended bowel preparation regimen. A proposed surgery time of 8:00 a.m. has been used.

Pre-op Day 3:Minimum residue or clear liquid diet. Bisacodyl, 1 tablet orally at 6:00 p.m.

Pre-op Day 2:Minimum residue or clear liquid diet. Magnesium sulfate, 30 mL, 50% solution (15 g) orally at 10:00 a.m., 2:00 p.m., and 6:00 p.m. Enema at 7:00 p.m. and 8:00 p.m.

Pre-op Day 1:Clear liquid diet. Supplemental (IV) fluids as needed. Magnesium sulfate, 30 mL, 50% solution (15 g) orally at 10:00 a.m., and 2:00 p.m. Neomycin sulfate (1 g) and erythromycin base (1 g) orally at 1:00 p.m., 2:00 p.m. and 11:00 p.m. No enema.

Day of Operation:Patient evacuates rectum at 6:30 a.m. for scheduled operation at 8:00 a.m.

Contraindications

Neomycin sulfate oral preparations are contraindicated in the presence of intestinal obstruction and in individuals with a history of hypersensitivity to the drug. Patients with a history of hypersensitivity or serious toxic reaction to other aminoglycosides may have a cross-sensitivity to neomycin.

Neomycin sulfate oral preparations are contraindicated in patients with inflammatory or ulcerative gastro- intestinal disease because of the potential for enhanced gastrointestinal absorption of neomycin.

Adverse Reactions

The most common adverse reactions to oral neomycin sulfate are nausea, vomiting and diarrhea. The “Malabsorption Syndrome” characterized by increased fecal fat, decreased serum carotene and fall in xylose absorption has been reported with prolonged therapy. Nephrotoxicity, ototoxicity and neuromuscular blockage have been reported (see BOXED WARNINGS and PRECAUTIONS sections).

Overdosage

Because of low absorption, it is unlikely that acute overdosage would occur with oral neomycin sulfate. However, prolonged administration could result in sufficient systemic drug levels to produce neurotoxicity, ototoxicity and/or nephrotoxicity.

Hemodialysis will remove neomycin sulfate from the blood.

Description

Neomycin Sulfate Tablets, USP for oral administration, contain neomycin which is an antibiotic obtained from the metabolic products of the actinomycete Streptomyces fradiae.

Structurally, Neomycin Sulfate, USP may be represented as follows:

Chemically, it is O-2,6-diamino-2,6-dideoxy-α-D- glucopyranosyl-(1→3)- O-β-D-ribofuranosyl-(1→ 5)- O- [2,6-diamino-2,6-dideoxy -α-D- glucopyranosyl-(1→ 4)]-2-deoxy-D-streptamine. Neomycin B is identical except that the α -D- glucopyranosyl residue in the neobiosamine moiety is β-L-idopyranosyl.

Each tablet contains 500 mg Neomycin Sulfate, USP (equivalent to 350 mg neomycin base).

Inactive Ingredients:anhydrous lactose, calcium stearate, and povidone.

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Clinical Pharmacology

Neomycin sulfate is poorly absorbed from the normal gastrointestinal tract. The small absorbed fraction is rapidly distributed in the tissues and is excreted by the kidney in keeping with the degree of kidney function. The unabsorbed portion of the drug (approximately 97%) is eliminated unchanged in the feces.

Growth of most intestinal bacteria is rapidly suppressed following oral administration of neomycin sulfate, with the suppression persisting for 48 to 72 hours. Nonpathogenic yeasts and occasionally resistant strains of Enterobacter aerogenes(formerly Aerobacter aerogenes) replace the intestinal bacteria.

As with other aminoglycosides, the amount of systemically absorbed neomycin transferred to the tissues increases cumulatively with each repeated dose administered until a steady state is achieved. The kidney functions as the primary excretory path as well as the tissue binding site, with the highest concentration found in the renal cortex. With repeated dosings, progressive accumulation also occurs in the inner ear. Release of tissue-bound neomycin occurs slowly over a period of several weeks after dosing has been discontinued.

Protein binding studies have shown that the degree of aminoglycoside protein binding is low and, depending upon the methods used for testing, this may be between 0% and 30%.

Microbiology

In vitro tests have demonstrated that neomycin is bactericidal and acts by inhibiting the synthesis of protein in susceptible bacterial cells. It is effective primarily against gram-negative bacilli but does have some activity against gram-positive organisms. Neomycin is active in vitroagainst Escherichia coliand the Klebsiella- Enterobactergroup. Neomycin is not active against anaerobic bowel flora.

Susceptibility Testing

For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.

How Supplied / Storage and Handling

Neomycin Sulfate Tablets, USP 500 mg (equivalent to 350 mg of neomycin base per tablet) are available as white to off-white, round tablets debossed with “ CE” on one side and “ 119”, on the other side and are supplied in:

Bottles of 90 (NDC 62135-443-90)

Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].

Dispense in tight containers as defined in the USP/NF.

KEEP THIS AND ALL MEDICATIONS OUT OF THE REACH OF CHILDREN.

Manufactured for
Chartwell RX, LLC.
Congers, NY 10920

L71735

Rev. 02/2026

Professional Information — Neomycin Sulfate