Petracin

This is indicated for the prophylaxis and local treatment of superficial ocular infections due to oxytetracycline and polymyxin-sensitive organisms, including infections due to streptococci, rickettsiae, E. coli, and A. aerogenes, such as conjunctivitis, keratitis, pink eye, corneal ulcer, blepharitis
... Read more
This is indicated for the prophylaxis and local treatment of superficial ocular infections due to oxytetracycline and polymyxin-sensitive organisms, including infections due to streptococci, rickettsiae, E. coli, and A. aerogenes, such as conjunctivitis, keratitis, pink eye, corneal ulcer, blepharitis in dogs, cats, cattle, sheep, and horses; ocular infections due to secondary bacterial complications of distemper in dogs, and bacterial inflammatory conditions which may occur secondary to other infectious diseases in the above species.

Dosage & Administration

Oxytetracycline Hydrochloride and Polymyxin B Sulfate Ophthalmic Ointment should be administered topically to the eye 2-4 times daily.

All medicines may cause side effects, but many people have no, or minor, side effects. When used in small doses, no common side effects have been reported with Petracin. Seek medical attention right away if any of these severe side effects occur: Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); eye swelling or redness.

Serious, life threatening, hypersensitivity (anaphylactic) reactions have been reported in some cats following application of antibiotic ophthalmic preparations. If your cat has swelling of the face, itching, appears weak, vomits, or has difficulty breathing within 4 hours of application you should discontinue treatment and contact your veterinarian immediately. The use of oxytetracycline and other antibiotics may result in an overgrowth of resistant organisms such as Monilia, staphylococci, and other species of bacteria. If new infections due to nonsensitive bacteria or fungi appear during therapy, appropriate measures should be taken.

Oxytetracycline inhibits cell growth by inhibiting translation. It binds to the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. The binding is reversible in nature. Oxytetracycline is lipophilic and can easily pass through the cell membrane or passively diffuses through porin channels in the bacterial membrane.
The broad-spectrum effectiveness of this ointment against both gram-positive and gram-negative organisms is enhanced by the particular effectiveness of polymyxin B against infections associated with gram-negative organisms, especially those due to Pseudomonas aeruginosa, where polymyxin B is the antibiotic of choice. In addition, there is evidence to indicate that polymyxin B sulfate possesses some antifungal activity.