Neomycin Sulfate
Antibiotic
View Brand Names (1)Dose and dosage
Snake:
For susceptible infections:
a) For bacterial gastritis: gentamicin 2.5 mg/kg IM every 72 hours with oral neomycin 15 mg/kg plus oral live lactobacillus (Burke 1986)
For oral administration to treat susceptible enteral infections:
a) 4–7.5 grams/day PO divided 2–4 times daily at regular intervals.
Calves: 2–3 grams/day, PO divided 2–4 times daily at regular intervals. Doses are not standardized; use for general guidance only. (Brander et al. 1982)
b) 10–20 mg/kg q12h (general guideline only). (Jenkins 1986)
c) 7–12 mg/kg, PO q12h (Howard 1986)
d) Feed at levels of 70–140 grams/ton of feed or mix the appropriate dose in the drinking water which will be consumed by animals in 12 hours to provide 11 mg/kg or mix with reconstituted milk replacers to provide 200–400 mg/gallon. (Label directions; Neomix Ag® 325—Upjohn)
For oral administration to treat susceptible enteral infections:
a) Adults: 4–7.5 grams/day PO divided 2–4 times daily at regular intervals. Foals: 2–3 grams/day PO divided 2–4 times daily at regular intervals. Doses are not standardized; use for general guidance only. (Brander et al. 1982)
b) 5–15 mg/kg PO once daily (Robinson 1987)
For intrauterine infusion:
a) Neomycin alone: 3–4 grams.
Combination of neomycin (2 grams) and procaine penicillin G (3,000,000 IU), Combination of Neomycin (1grams) and Polymyxin B (40,000 IU), Furaltadone (600 mg) and penicillin G (Sodium or potassium, 3,000,000–5,000,000 IU). Little science is available for recommending doses, volume infused, frequency, diluents, etc. Most intrauterine treatments are commonly performed every day or every other day for 3–7 days. (Perkins 1999)
For oral administration to treat susceptible enteral infections:
a) Lambs: 0.75–1 grams/day PO divided 2–4 times daily at regular intervals. Doses are not standardized; use for general guidance only. (Brander et al. 1982)
b) Feed at levels of 70–140 grams/ton of feed or mix the appropriate dose in the drinking water which will be consumed by animals in 12 hours to provide 11 mg/kg or mix with reconstituted milk replacers to provide 200–400 mg/gallon. (Label directions; Neomix Ag® 325—Upjohn)
For treatment of hepatic encephalopathy:
a) A check list for acute management of hepatic encephalopathy includes: 1) Lactulose (orally, or by enema if stupor or seizures); 2) NPO for 12 to 24 hours; 3) If no response, add metronidazole orally at 15 mg/kg/day; 4) If no response, add neomycin orally at 20 mg/kg PO three times daily. 5) Provide IV fluids with potassium (and dextrose for patients with portosystemic shunts or severe cirrhosis). 6) Add anti-ulcer therapy (GI bleeding is a protein load in hepatic encephalopathy), and add vitamin K1 if jaundiced. 7) Withhold any glucocorticoids until encephalopathy is resolved! 8) Give as much dietary protein as tolerated; increase the lactulose dosage if needed. (Trepanier 2008)
b) For adjunctive management of portosystemic shunts: 10–20 mg/kg PO two to three times a day. (Twedt 2009)
c) Animals that are neurologically and systemically stable should be treated with orally-administered nonabsorbable antibiotics in order to decrease the numbers of urease-producing bacteria within the gastrointestinal tract. If using neomycin: 20 mg/kg PO q12h. Avoid neomycin if any evidence of intestinal bleeding, ulcerations, or renal failure. The use of oral lactulose therapy, in conjunction with or as an alternative to antibiotics, is also beneficial in neurologically stable animals. The combination of neomycin and lactulose may be synergistic. (Silverstein 2009)
d) 15 mg/kg as an enema every 6 hours after a cleansing enema or 10–20 mg/kg, PO every 6 hours. May be used with lactulose. (Johnson 1986) For GI tract infections:
a) For campylobacteriosis: 20 mg/kg PO q12h (Willard 2003) For systemic therapy (Caution: Very nephrotoxic):
a) 3.5 mg/kg IV, IM or SC q8h (Kirk 1989)
For treatment of hepatic encephalopathy:
a) See “A check list for acute management of hepatic encephalopathy” in Dog dose section above.
b) 22 mg/kg q8h PO (Cornelius, Bartges et al. 2000)
c) Lactulose at 0.5–1 mg/kg PO q8h with or without neomycin at 20 mg/kg PO q8–12h. (Marks 2004)
d) Animals that are neurologically and systemically stable should be treated with orally-administered nonabsorbable antibiotics in order to decrease the numbers of urease-producing bacteria within the gastrointestinal tract. If using neomycin: 20 mg/kg PO q12h. Avoid neomycin if any evidence of intestinal bleeding, ulcerations, or renal failure. The use of oral lactulose therapy, in conjunction with or as an alternative to antibiotics, is also beneficial in neurologically stable animals. The combination of neomycin and lactulose may be synergistic. (Silverstein 2009)
For GI tract infections: For campylobacteriosis:
a) 20 mg/kg PO q12h (Willard 2003) For systemic therapy (Caution: Very nephrotoxic):
a) 3.5 mg/kg IV, IM or SC q8h (Kirk 1989)
For susceptible enteric infections:
a) 10–20 mg/kg, PO twice to four times daily (Williams 2000)
Note: Contraindicated in rabbits/hares
a) Chinchillas: 15 mg/kg, PO once daily. Gerbils: 100 mg/kg, PO once daily, Guinea Pigs: 8 mg/kg, PO once daily.
Hamsters: 100 mg/kg, PO once daily, or 0.5 mg/mL in drinking water.
Mice, Rats: 50 mg/kg, PO once daily (Adamcak & Otten 2000)
For oral administration to treat susceptible enteral infections:
a) Young pigs: 0.75–1 grams/day, PO divided 2–4 times daily at regular intervals. Doses are not standardized; use for general guidance only. (Brander, Pugh, and Bywater 1982)
b) 7–12 mg/kg, PO q12h (Howard 1986)
For bacterial enteritis:
a) Chickens, turkeys, ducks: Feed at levels of 70–140 grams/ton of feed or mix the appropriate dose in the drinking water which will be consumed by animals in 12 hours to provide 11 mg/kg (Label directions; Neomix Ag® 325—Upjohn)
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Iindicated for the prevention and treatment of bacterial enteritis caused by microorganisms like E. coli, Salmonella spp., Campylobacter spp., Pasteurella, Staphylococci & Listeria spp. in poultry, calf, goat, sheep & swine.
Because neomycin is more nephrotoxic and less effective against several bacterial species than either gentamicin or amikacin, its use is generally limited to topical formulations for skin, eyes, and ears, oral treatment of enteric infections, to reduce microbe numbers in the colon prior to colon surgery, and oral or enema administration to reduce ammonia-producing bacteria in the treatment of hepatic encephalopathy. Doses for parenteral administration are listed below, but should be used only with extreme caution due to the drug’s toxic potential.
- Oral: Hypersensitive to aminoglycosides, intestinal blockage;
- rabbits
Aminoglycoside antibiotic usually used orally (gut “sterilization”) or in topical formulations.
Neomycin has a mechanism of action and spectrum of activity (primarily gramnegative aerobes) similar to the other aminoglycosides, but in comparison to either gentamicin or amikacin, it is significantly less effective against several species of gram-negative organisms, including strains of Klebsiella, E. coli, and Pseudomonas. However, most strains of neomycin-resistant bacteria of these species remain susceptible to amikacin. More detailed information on the aminoglycosides mechanism of action and spectrum of activity is outlined in the amikacin monograph.
It irreversibly binds to the 30S ribosomal subunit of bacteria & thereby inhibits bacterial protein synthesis.
The following drug interactions have either been reported or are theoretical in humans or animals receiving oral neomycin and may be of significance in veterinary patients:
DIGOXIN: Oral neomycin with orally administered digoxin may result in decreased absorption. Separating the doses of the two medications may not alleviate this effect. Some human patients (<10%) metabolize digoxin in the GI tract and neomycin may increase serum digoxin levels in these patients. It is recommended that enhanced monitoring be performed if oral neomycin is added or withdrawn from the drug regimen of a patient stabilized on a digitalis glycoside.
METHOTREXATE: Absorption may be reduced by oral neomycin but is increased by oral kanamycin (found in Amforal®)
OTOTOXIC, NEPHROTOXIC DRUGS: Although only minimal amounts of neomycin are absorbed after oral or rectal administration, the concurrent use of other ototoxic or nephrotoxic drugs with neomycin should be done with caution
PENICILLIN VK (oral): Oral neomycin should not be given concurrently with oral penicillin VK as malabsorption of the penicillin may occur
WARFARIN: Oral neomycin may decrease the amount of vitamin K absorbed from the gut; this may have ramifications for patients receiving oral anticoagulants
Refer to the amikacin monograph for more information regarding drug interactions with parenteral neomycin.
Refer to the amikacin monograph for more information regarding these topics with parenteral neomycin; however, parenterally administered neomycin is much more nephrotoxic than is amikacin.
Rarely, oral neomycin may cause ototoxicity, nephrotoxicity, severe diarrhea, and intestinal malabsorption.
In humans, the FDA categorizes this drug as category C for use during pregnancy (Animal studies have shown an adverse effect on the fetus, but there are no adequate studies in humans; or there are no animal reproduction studies and no adequate studies in humans.) In a separate system evaluating the safety of drugs in canine and feline pregnancy (Papich 1989), this drug is categorized as class: A (Probably safe. Although specific studies may not have proved he safety of all drugs in dogs and cats, there are no reports of adverse effects in laboratory animals or women.)
Neomycin is excreted in cow’s milk following a single IM injection. If used orally, it is unlikely neomycin poses significant systemic risk to nursing offspring, but may negatively alter gut flora and cause diarrhea.
Oral neomycin is contraindicated in the presence of intestinal obstruction or if the patient is hypersensitive to aminoglycosides.
In neonates, orally administered neomycin can yield high systemic levels; avoid use in neonatal patients.
Chronic usage of oral aminoglycosides may result in bacterial or fungal superinfections.
Because aminoglycosides can cause irreversible ototoxicity when administered parenterally, they should be used with caution in “working” dogs.
Aminoglycosides should be used with caution in patients with neuromuscular disorders (e.g., myasthenia gravis) due to their neuromuscular blocking activity.
Because aminoglycosides are eliminated primarily through renal mechanisms, when administered parenterally they should be used cautiously, preferably with serum monitoring and dosage adjustment in neonatal or geriatric animals. When neomycin is given orally, only perhaps 3% of a dose is absorbed, but use with caution in patients with renal dysfunction.
Aminoglycosides are generally considered contraindicated in rabbits/hares, as they adversely affect the GI flora balance in these animals. Oral neomycin has been associated with antibiotic-associated diarrhea (enterocolitis) in horses and it is not commonly used in this species.
Poultry: Meat- 0 (zero) day. Egg- Egg must not be consumed up to 1 day after administration.
Calf, goat, sheep & swine: Meat- Meat must not be consumed up to 1 day after administration.
Milk- Milk must not be consumed up to 1 day after administration.