Abstract

Misoprostol, a synthetic prostaglandin E₁ analog, is used to decrease gastric secretion and increase uterine contraction frequency in both veterinary and human medicine. Phenytoin is used as an anticonvulsant and antidysrhythmic, and is commonly incorporated into euthanasia solutions in veterinary medicine. These drugs have been compounded together and used topically to treat ulcers in human medicine. Mechanisms of action include stimulation of fibroblasts, increased collagen deposition, glucocorticoid antagonism and antimicrobial activity. Misoprostol/phenytoin gel (MP) was used for treatment of dermal ulcerations due to conspecific aggression and/or environmental trauma in multiple teleost cases at the Audubon Aquarium of the Americas and its effectiveness was evaluated.

A community compounding pharmacist prepared the two drugs into a fine powder, consisting of 0.0024% misoprostol and 2% phenytoin. During treatment, the affected teleost was manually restrained or sedated with tricaine methanesulfonate, and temporarily removed from the water. Lesion sites were cleaned with dilute chlorohexidine and rinsed with saline. A thin layer of MP was applied to the ulcerated area. Once in contact with moist surfaces, the powder quickly transformed into an opaque, sticky gel-like substance. Additional saline or enclosure water was applied to further transform the powder to gel if needed. Once a thin layer was established, the patient was returned to the normal enclosure. Depending on the lesion site and application thickness, the compounded gel typically remained in place for 3–5 days, and re-application was performed as needed. The gel acts as a protective layer, potentially decreasing osmotic stressors to the patient while promoting granulation tissue and healing. This compound has been used in multiple marine and freshwater species, including Channel Catfish (Ictalurus punctatus), Porcupine Pufferfish (Diodon hystrix), Green Moray Eel (Gymnothorax funebris), Chainlink Moray Eel (Echidna catenata), and Cownose Rays (Rhinoptera bonasus). No adverse reactions have been noted due to application of the drugs in any patient. Misoprostol/phenytoin gel is easily applied, durable in the aquatic environment, and subjectively decreases healing time in ulcerated dermal tissue of teleosts.

Acknowledgements

The author thanks Randy Carr of Carr Drugs and the Audubon Aquarium of the Americas for their technical assistance.

* Presenting author