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Neomycin Side Effects

For the Consumer

Applies to neomycin: oral solution, oral tablet


Oral route (Tablet; Solution)

Systemic absorption occurs following oral administration and toxic reactions may occur. Therapy has been associated with potential neurotoxicity, ototoxicity, and nephrotoxicity. Patients with impaired renal function, advanced age, dehydration, and those who receive high dosage or prolonged therapy are at an increased risk of toxicity. Monitor renal and auditory function during therapy. Aminoglycoside-induced ototoxicity is usually irreversible. Neuromuscular blockade and respiratory paralysis have also been reported following administration. Concurrent use of other potentially neurotoxic or nephrotoxic agents, or potent diuretics should be avoided.

Along with its needed effects, neomycin 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


The most commonly reported side effects included diarrhea, nausea, and vomiting.[Ref]


Common (1% to 10%): Diarrhea, nausea, vomiting

Frequency not reported: Increased fecal fat, increased salivation, steatorrhea, stomatitis[Ref]


Metabolic syndrome occurred with prolonged therapy, and included increased fecal fat, steatorrhea, decreased serum carotene, and a fall in xylose absorption. Steatorrhea and diarrhea occurring during metabolic syndrome can be very severe.[Ref]

Frequency not reported: Decreased serum carotene, electrolyte disturbances, fall in xylose absorption, hypocalcemia, hypokalemia, hypomagnesemia, malabsorption syndrome[Ref]

Nervous system

Frequency not reported: Neuromuscular blockade/blockage, neurotoxicity, nystagmus, paresthesia, vestibular toxicity[Ref]


Frequency not reported: Drug fever, ototoxicity, permanent bilateral ototoxicity[Ref]


Frequency not reported: Anaphylaxis, cross-sensitivity, hypersensitivity reactions[Ref]


Frequency not reported: Increased bilirubin levels, increased hepatic enzyme levels[Ref]


Frequency not reported: Blood dyscrasias, hemolytic anemia[Ref]


Frequency not reported: Confusion, disorientation[Ref]


Frequency not reported: Dermatitis, pruritus[Ref]


Frequency not reported: Nephrotoxicity[Ref]


Superinfection occurred with prolonged therapy.[Ref]

Frequency not reported: Superinfection[Ref]


Frequency not reported: Respiratory paralysis[Ref]


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

2. "Product Information. Mycifradin (neomycin)." Emerson Laboratories, Texarkana, TX.

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.

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