Neomycin

Neomycin In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• A concentration-dependent antimicrobial agent.
• Inhibits the process of bacterial protein synthesis.
• It achieves this by gaining entry into the bacterial cell by a carrier mechanism that is dependent on the presence of oxygen.
• Similar to other aminoglycosides, the method of cell-killing is concentration-dependent, which results in a significant post-antibiotic effect.

Uses of Neomycin 

• It shows a primary efficacy against Gram-negative bacteria, with a notable sensitivity shown in some species of Staphylococcus and Enterococcus.
• Obligate anaerobic bacteria and a significant number of haemolytic streptococci exhibit resistance.
• Parenteral neomycin, due to its significant nephrotoxic and ototoxic properties, is employed in topical applications for the treatment of skin, ear, or mucous membrane infections.
• Oral administration of neomycin is employed as a means to decrease the abundance of intestinal bacteria, particularly in the context of managing hepatic encephalopathy.
• Similar to other aminoglycosides, oral absorption of this medication is not possible unless there is gastrointestinal ulceration.
• The utilisation of this medication, frequently in conjunction with antimuscarinic drugs, has been observed in the therapeutic management of non-specific bacterial enteritides.
• Neomycin exhibits enhanced activity inside an alkaline environment.

Dose of Neomycin in Dogs and Cats

Dogs, Cats:

Oral:

• 20 mg/kg p.o. q6–8h; or per rectum as a retention enema for management of acute hepatic encephalopathy only.
• As the drug is not absorbed, it is not an effective treatment for other sites of infection.
• In stable animals, decrease frequency to q12h.

Ophthalmic: 1 drop/eye q6–8h.

Otic: 2–12 drops/ear or apply liberally to skin q4–12h.

Side Effects of Neomycin in Dogs and Cats

• Neomycin may cause systemic, ototoxicity, and nephrotoxicity in rare cases of sustained high-dose oral therapy or severe GI ulceration/inflammatory bowel illness due to absorption.
• Nephrotoxicity and ototoxicity are possible negative effects of parenteral usage.
• Patients may get severe diarrhoea/malabsorption syndrome and bacterial or fungal superinfections.
• Local irritation may occur with topical ophthalmology.

Contraindications of Neomycin in Dogs and Cats

• For systemic use, do not use in animals with pre-existing renal disease.
• Do not use ear preparations if the tympanum is ruptured.

Some Notes:

• Absorption of digoxin, methotrexate, potassium, and vitamin K may decrease.
• Other ototoxic and nephrotoxic drugs, e.g. furosemide, should be used with caution in
  patients on oral neomycin therapy as the combinations are likely to have synergistic toxicity.