Pharmacokinetics of nebulized and subcutaneously implanted terbinafine in cottonmouths (Agkistrodon piscivorus)

Abstract

Ophidiomyces ophiodiicola, the causative agent of snake fungal disease, is proposed as a serious threat to the conservation of several snake populations. The objective of this study was to determine the pharmacokinetic parameters of terbinafine administered through nebulization and a sustained subcutaneous implant as potential treatments of Ophidiomyces in reptiles. Seven adult cottonmouths (Agkistrodon piscivorus) were used in single-dose trials. Each snake was nebulized with terbinafine (2 mg/ml) for 30 min and had blood collected before nebulization and up to 12 hr after nebulization. Following a 5-month washout, the same snakes were administered a subcutaneous implant containing 24.5 mg terbinafine; blood was collected at baseline, 1 day postimplant placement, and then once weekly for 9 weeks. Plasma for both studies was analyzed by high-performance liquid chromatography. The mean plasma concentrations of nebulized terbinafine peaked between 0.5 and 4 hr. The subcutaneously implanted terbinafine reached therapeutic concentrations on day 1 and maintained therapeutic for over 6 weeks. These methods and doses are recommended as potential treatment options for snake fungal disease in reptiles.

Fungal dermatitis secondary to a hemipenal plug in a rhinoceros viper (Bitis nasicornis)

“…Previous studies have demonstrated that nebulisation is effective in treating ophidiomycosis. 7 Fusarium spp. are ubiquitous soil saprophytes and were found in the freshly shed skins of 4% of 127 captive squamate reptiles surveyed.…”

Emydomyces testavorans , a New Genus and Species of Onygenalean Fungus Isolated from Shell Lesions of Freshwater Aquatic Turtles

“…Reported MIC values suggest that Emydomyces is susceptible to antifungal drugs commonly used in the treatment of reptilian fungal infections, such as itraconazole, voriconazole, and terbinafine (4,30). However, only a few studies evaluating the safety, efficacy, and pharmacokinetics of these antifungal drugs have been performed in a limited selection of reptile species (30)(31)(32). Toxicity associated with voriconazole administration has been reported in at least one species of snake with clinically relevant dosages (30).…”

Diagnosis, treatment and post‐release monitoring of an eastern black rat snake (Pantherophis alleghaniensis) with ophidiomycosis and traumatic injuries

“…The snake was treated with terbinafine (Terbinafine, 250 mg; InvaGen Pharmaceuticals, Hauppauge, NY, USA) via nebulisation at 2 mg/ml for 30 minutes every 24 hours from 21 July 2015 to 19 August 2015 6. In October 2015, following nebulisation treatment, the animal was negative for O ophiodiicola on qPCR.…”