CAS number  YesY
ChemSpider  YesY
ATC code C04
Jmol-3D images Image 1
Molecular formula C18H23NO3
Molar mass 301.38 g mol−1
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N   YesY/N?)

Isoxsuprine (used as isoxsuprine hydrochloride) is a drug used as a vasodilator[2] in humans (under the trade name Duvadilan) and equines. Isoxsuprine is a beta-adrenergic agonist that causes direct relaxation of uterine and vascular smooth muscle via beta-2 receptors.[3]


  • Use in equines 1
    • Reasons for use and controversy 1.1
    • Precautions and side-effects 1.2
    • Administration 1.3
  • Use in humans 2
  • References 3

Use in equines

Reasons for use and controversy

Isoxsuprine is most commonly used to treat hoof-related problems in the horse, most commonly for laminitis and navicular disease, as its effects as a vasodilator are thought to increase circulation within the hoof to help counteract the problems associated with these conditions.

There are many veterinarians—and horsemen—who do not believe isoxsuprine to be effective. Its use is therefore rather controversial within the veterinary field.

Precautions and side-effects

Isoxsuprine may increase the human's heart rate, cause changes in blood pressure, and irritate the GI tract. It should therefore be used with caution if combined with other drugs that affect blood pressure, such as sedatives and anesthetic drugs. Because it is a vasodilator, it should not be used in horses that are bleeding, or in mares following foaling.

Isoxsuprine is a prohibited class B drug in FEI-regulated competition, and is often prohibited by other equine associations. It may be detected in the urine for several weeks or months following administration. It is therefore important to check the drug-rules within an animal's given competitive organization, before administering the drug.


Isoxsuprine is given orally, and many horses find the pills quite palatable.[4]

Use in humans

Isoxsuprine it is used in humans for treatment of premature labor, i.e. a tocolytic,[5] and as a vasodilator for the treatment of cerebral vascular insufficiency, Raynaud's phenomenon, and other conditions.[6]


  1. ^ Isoxsuprine - Compound Summary, PubChem.
  2. ^ Gozo EG, Yebes RB (November 1984). "Hemodynamic effects of isoxsuprine in cardiac failure". Chest 86 (5): 736–40.  
  3. ^ Falkay, G.; Kovács, L. (1986). "Affinity of tocolytic agents on human placental and myometrial beta-adrenergic receptors". Journal of perinatal medicine 14 (2): 109–113.  
  4. ^ Forney, Barbara C (2007). Equine Medications. Lexington, KY: Blood Horse Publications. 
  5. ^ Giorgino, F. L.; Egan, C. G. (2010). "Use of isoxsuprine hydrochloride as a tocolytic agent in the treatment of preterm labour: A systematic review of previous literature". Arzneimittel-Forschung 60 (7): 415–420.  
  6. ^ Isoxsuprine