SILVER SULFADIAZINE (OPHTHALMIC)
Indications/PharmacologySilver Sulfadiazine Cream is a broad spectrum agent which covers bacteria(gram positive and negative) and fungal agents. It has been used extensively in people suffering from skinburns. It is nontoxic to the skin, conjunctiva and cornea and has been used in the last several years forcases of fungal keratitis. Particularly good results have been noted in cases of superficial keratitis prior todevelopment of advanced disease. Clinical response is better when used early in the course of the disease.
Treatment with silver sulfadiazine is considered non-conventional in people. It is gaining in popularity inthe treatment of equine fungal keratitis by veterinary ophthalmologists. For medico-legal reasons, in veryexpensive horses in which litigation may be an issue, treatment with more conventional therapy(Natamycin) may be indicated first, or consideration can be given to signed consent regarding treatmentwith Silver Sulfadiazine. The initial response to this drug has been promising, however.Suggested Dosages/Precautions/Adverse Effects - The commercially available product is a cream, butcan be delivered into the conjunctival sac using a tuberculin syringe, without the needle. A typicaltreatment dose is 0.2 ml drawn into a syringe. It will not pass through standard sized subpalpebral lavagecatheters, although it may be administered through large medication administration systems using redrubber feeding tubes passed through the lid, with variable results getting the medication to pass throughthe tube. It is probably best applied manually. The cream sticks well to the cornea which probablyimproves effectiveness, similar to natamycin, as compared to miconazole. Treatment regimes are similarto the other antifungal agents with very frequent applications necessary during the early phases of thetreatment and reduction in therapy based upon clinical response. Daily debridement of the necroticcorneal stroma and epithelium will improve penetration of the drug and the clinical response.
The medication is inexpensive and is available from any pharmacy, but it is not labeled for use in eyes.
The label (package insert) specifically states "not to be used in eyes" so liability for use in eyes restssolely with the prescribing veterinarian and some pharmacists may be unwilling to dispense thismedication for ophthalmic use.
Dosage Forms/Preparations/FDA Approval Status - Veterinary-Approved Products: None
Human-Approved Products:Silver Sulfadiazine Topical (not an ophthalmic product) 10 mg per gram in a water miscible creambase. Available in 20, 50, 400, and 1000 g containers; Silvadene®-(Marion); Flint SSD® (Flint); Rx
Antiviral drugs are used most commonly in clinical practice for the treatment of feline ocular herpesvirus infections. Simple acute conjunctivitis is best managed with symptomatic antibiotic therapy alone(i.e., tetracycline treatment). The development of concurrent corneal disease, however, indicates thatconsideration should be given to the use of antiviral drugs. Persistent cases of conjunctivitis in the cat dueto feline herpes virus infection may also benefit from treatment with topical antiviral drugs.