Triple Antibiotic Ophthalmic Preparations for Dogs and Cats
Overview of Antibiotic Ophthalmic Preparations for Canines and Felines
Combination antibiotic ophthalmic drugs, better known as Neosporin®, Vetropolycin®, TriOptic-P®, or Optiprime®, are often used in the treatment and prevention of bacterial infections of the eye. When one or two other antibacterial agents are combined, the mixture has greater potency and broader antibacterial activities. Many of the agents included in these combination products are not as effective when used alone for ocular infections.
Examples of combination products include polymyxin-bacitracin-neomycin, polymyxin-neomycin-gramicidin, and polymyxin-bacitracin.
Neomycin sulfate is bactericidal for many gram-positive and some gram-negative bacteria.
Polymyxin B is bactericidal for some gram-negative bacteria.
Bacitracin zinc has its greatest activity against gram-positive agents.
Gramicidin D is a mixture of three pairs of antibacterial substances (gramicidin A, B, C), and has antibacterial activity against gram-positive agents.
The combination products may be used to treat a variety of infections, including staphylococcal, streptococcal and E. coli bacteria.
Triple antibiotic drugs are all prescription drugs and can only be obtained from a veterinarian or by prescription from a veterinarian.
Brand Names or Other Names of Antibiotic Eye Medication
These drugs are registered for use in humans and animals.
Human formulations: AK-Poly-Bac® and AK-Spore® (Akorn), Polymycin® (Medical Ophthalmics), Neosporin® (Monarch), B-P and B-N-P ointments (Bausch & Lomb) and various generic preparations
Veterinary formulations: Vetropolycin® (Pitman-Moore), Mycitracin® (Upjohn), Neobacimyx® (Schering), Trioptic-P® (Pfizer), Optiprime® (Syntex) and various generic preparations
Uses of Combination Antibiotic Eye Medication for Dogs and Cats
Combination antibiotic ophthalmic preparations are used in the treatment of bacterial conjunctivitis, corneal ulcers and wounds, some forms of keratitis, blepharitis and eyelid wounds, and dacryocystitis.
Combination products are also useful in the management of keratoconjunctivitis sicca (KCS), also called dry eye.
Combination products may also be used before and after eye surgery.
Precautions and Side Effects
While generally safe and effective when recommended by a veterinarian, combination antibiotic ophthalmic preparations can cause side effects in some animals.
Combination antibiotic ophthalmic preparations should not be used in animals with known hypersensitivity or allergy to the drug.
Side effects produced by combination products have been linked primarily to the neomycin component. With prolonged use, the eye may become sensitized to the aminoglycoside antibiotic, neomycin. Hypersensitivity reactions are more common in the dog and appear as marked redness of the conjunctiva and third eyelid. The eyelids may also become red and partially depigmented.
Use of topical neomycin must be done cautiously in cats, because of rare reports of anaphylaxis that have occurred following its use.
Prolonged use of any topical antibiotic preparation may predispose the animal to the development of resistance.
There are no known drug interactions for these preparations, although there is no medical rationale for using them with each other, or with other topical ophthalmic antibiotics.
If multiple eye medications are being administered to an animal, it is advisable to separate all solutions from each other by 2 to 3 minutes, and in some instances it is preferable to administer solutions (drops) before ointments.
How Antibiotic Combination Eye Medications Are Supplied
Both ointments and solutions are available.
Ointment is available in 3.5 gram and 5 gram tubes. Solution is available in 5 to 10 ml bottles.
The most common antibiotic concentrations used in the ointment preparations are 400 to 500 units of bacitracin zinc, 10,000 units of polymyxin B and 3.5 mg neomycin. Typical concentrations per ml of solution are 1.75 mg neomycin, 10,000 units polymyxin B, and 0.025 mg gramicidin.
Dosing Information of Antibiotic Eye Medication for Dogs and Cats
Medication should never be administered without first consulting your veterinarian.
The frequency of administration of these antibiotics is dependent upon the underlying disease and the form of medication used. Solutions have shorter contact times with the eye, and must be applied more frequently than ointments. Your veterinarian may instruct you to apply these medications anywhere from 2 to 12 times daily.
The duration of administration depends on the condition being treated, response to the medication, and the development of any adverse effects. Unless your veterinarian advises otherwise, be certain to complete the prescription to prevent relapse or prevent the development of resistance.