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Neo-Fradin Side Effects

Generic Name: neomycin

Note: This document contains side effect information about neomycin. Some of the dosage forms listed on this page may not apply to the brand name Neo-Fradin.

For the Consumer

Applies to neomycin: oral solution, oral tablet

Along with its needed effects, neomycin (the active ingredient contained in Neo-Fradin) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking neomycin:

  • Any loss of hearing
  • clumsiness
  • diarrhea
  • difficulty in breathing
  • dizziness
  • drowsiness
  • greatly decreased frequency of urination or amount of urine
  • increased amount of gas
  • increased thirst
  • light-colored, frothy, fatty-appearing stools
  • ringing or buzzing or a feeling of fullness in the ears
  • skin rash
  • unsteadiness
  • weakness

Some side effects of neomycin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
  • Irritation or soreness of the mouth or rectal area
  • nausea or vomiting

For Healthcare Professionals

Applies to neomycin: compounding powder, oral solution, oral tablet


Since oral neomycin (the active ingredient contained in Neo-Fradin) is absorbed systemically after oral administration, its use may result in nephrotoxicity, neurotoxicity and/or ototoxicity, even at recommended doses and in patients with normal renal function.[Ref]


The major renal side effect of oral neomycin (the active ingredient contained in Neo-Fradin) is nephrotoxicity, which has occurred even at recommended doses and in patients with normal renal function.[Ref]

Early signs of nephropathy include mild proteinuria, sloughing of renal tubular epithelial cells, formation of cellular casts, and decreases in creatinine clearance. Often there is a high output renal failure where daily urine volume may appear unchanged until significant increases in serum creatinine and BUN levels occur.

Neomycin damages renal tubules by causing tubular epithelial cell necrosis. It is considered the most nephrotoxic aminoglycoside.[Ref]

Nervous system

Early symptoms of neomycin-induced auditory toxicity may manifest as high tone hearing loss, tinnitus, or a feeling of fullness in the ear, or its onset may be asymptomatic. If ototoxicity occurs, the onset of hearing loss is between several days to 6 weeks after therapy begins; however, it may not occur for months or years after neomycin (the active ingredient contained in Neo-Fradin) has been discontinued. Symptoms of vestibulotoxicity may include tinnitus, vertigo and ataxia.

Neomycin is considered more ototoxic than vestibulotoxic. It progressively accumulates in the inner ear and which leads to sensory hair cell loss in the in the cochlea and damage to the stria vascularis. In an animal study, neomycin was found to be more ototoxic than gentamicin, kanamycin and dihydrostreptomycin.

One case report series describes 5 cases of hearing impairment associated with long-term oral neomycin therapy for hepatic encephalopathy. Doses ranged from 2 to 12 g/day and were administered for 8 to 28 months; in 2 cases paromomycin was also administered. Renal failure did not occur.[Ref]

Nervous system side effects associated with oral neomycin therapy have included neuromuscular blockade, respiratory paralysis, and eighth cranial nerve damage with hearing loss, even at recommended doses and in patients with normal renal function. Symptoms of neurotoxicity include numbness, tingling, muscle twitching, and convulsions.[Ref]


Oral neomycin (the active ingredient contained in Neo-Fradin) therapy may result in overgrowth of nonsusceptible organisms, especially fungi.[Ref]

A case of fatal Candida albicans pyelonephritis and septicemia following preoperative bowel preparation with oral neomycin and bacitracin has been reported.[Ref]


Gastrointestinal side effects most commonly include nausea, vomiting and diarrhea. Clostridium difficile colitis has also been reported with oral neomycin (the active ingredient contained in Neo-Fradin) therapy.[Ref]


1. "Product Information. Neomycin (neomycin)" Pharma-Tek, Huntington, NY.

2. Masur H, Whelton PK, Whelton A "Neomycin toxicity revisited." Arch Surg 111 (1976): 822-5

3. Lowry LD, May M, Pastore P "Acute histopathologic inner ear changes in deafness due to neomycin: a case report." Ann Otol Rhinol Laryngol 82 (1973): 876-80

4. Hasfurther DL, Bailey PL "Failure of neuromuscular blockade reversal after rocuronium in a patient who received oral neomycin." Can J Anaesth 43 (1996): 617-20

5. Berk DP, Chalmers T "Deafness complicating antibiotic therapy of hepatic encephalopathy." Ann Intern Med 73 (1970): 393-6

6. Greenberg LH, Momary H "Audiotoxicity and nephrotoxicity due to orally administered neomycin." JAMA 194 (1965): 237-8

7. Langman AW "Neomycin ototoxicity." Otolaryngol Head Neck Surg 110 (1994): 441-4

8. Thomas J, Marion MS, Hinojosa R "Neomycin ototoxicity." Am J Otolaryngol 13 (1992): 54-5

9. Ward KM, Rounthwaite FJ "Neomycin ototoxicity." Ann Otol Rhinol Laryngol 87 (1978): 211-5

10. Crosby DL "Fatal candidiasis following colonic sterilisation with neomycin and bacitracin." Br J Urol 39 (1967): 479-81

11. Bolton RP "Clostridium difficile-associated colitis after neomycin treated with metronidazole." Br Med J 2 (1979): 1479-80

12. Faergeman O "Effects and side-effects of treatment of hypercholesterolemia with cholestyramine and neomycin." Acta Med Scand 194 (1973): 165-7

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.