Isoxsuprine is reported to be a peripheral vasodilator used in human and veterinary medicine to treat ischaemic vascular disease. In horses, it is generally administered orally to treat navicular disease and other lower limb problems. To deflne the scope and duration of its pharmacological responses after oral administration, 6 horses were dosed with isoxsuprine HCI (1.2 mg/kg bwt) q. 12 h for 8 days and then tested to assess the duration and extent of pharmacological actions. There was no significant difference between isoxsuprine and control treatment values for heart rate, spontaneous activity, sweat production, anal muscle tone, core and skin temperatures, and cutaneous blood flow. The lack of pharmacological effect following oral administration was in sharp contrast to the marked response following i.v. dosing reported in earlier experiments.
Supported by grants from the Kentucky Racing Commission and the Kentucky Equine Drug Council, Lexington, Kentucky, the National and Florida offices of the Horsemen's Benevolent and Protective Association, Aventura, Florida, the Grayson-Jockey Club Research Foundation, Lexington, Kentucky and Mrs J. Hay Whitney.
Harkins, J. Daniel; Mundy, G. D.; Stanley, S.; Woods, W. E.; Sams, R. A.; Richardson, D. R.; Grambow, S. C.; and Tobin, Thomas, "Absence of detectable pharmacological effects after oral administration of isoxsuprine" (1998). Maxwell H. Gluck Equine Research Center Faculty Publications. 88.