Isoxsuprine

Isoxsuprine (used as isoxsuprine hydrochloride) is a drug used as a vasodilator^[4] in humans (under the trade name Duvadilan) and equines. Isoxsuprine is a β₂ adrenoreceptor agonist that causes direct relaxation of uterine and vascular smooth muscle via β₂ receptors.^[5]

Isoxsuprine

Clinical data
Pronunciation	/aɪˈsɒksjʊpriːn/
Trade names	Duvadilan, Vasodilan
MedlinePlus	a682831
Routes of administration	Oral (tablets)
ATC code	C04AA01 (WHO)
Legal status
Legal status	In general: ℞ (Prescription only)
Pharmacokinetic data
Bioavailability	~100% (humans),[1] 2.2% (horses; oral)[2]
Onset of action	1 hour
Elimination half-life	<3 hours (horses)[3]
Excretion	Mainly renal
Identifiers
IUPAC name 4-{1-Hydroxy-2-[(1-methyl-2-phenoxyethyl)amino]propyl}phenol
CAS Number	395-28-8
PubChem CID	3783
DrugBank	DB08941
ChemSpider	3651 Y
UNII	R15UI3245N
KEGG	D08092 Y
ChEMBL	ChEMBL1197051 N
CompTox Dashboard (EPA)	DTXSID9023178
ECHA InfoCard	100.006.272
Chemical and physical data
Formula	C18H23NO3
Molar mass	301.386 g·mol−1
3D model (JSmol)	Interactive image
SMILES O(c1ccccc1)CC(NC(C)C(O)c2ccc(O)cc2)C
InChI InChI=1S/C18H23NO3/c1-13(12-22-17-6-4-3-5-7-17)19-14(2)18(21)15-8-10-16(20)11-9-15/h3-11,13-14,18-21H,12H2,1-2H3 Y Key:BMUKKTUHUDJSNZ-UHFFFAOYSA-N Y

Use

In humans

Isoxsuprine is used in humans for treatment of premature labor, i.e. a tocolytic,^[6] and as a vasodilator for the treatment of cerebral vascular insufficiency, Raynaud's phenomenon, and other conditions.^[7]

Isoxsuprine may increase the 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.

In horses

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. Isoxsuprine is given orally, and many horses find the pills quite palatable.^[8] 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.

Because it is a vasodilator, it should not be used in horses that are bleeding, or in mares following foaling.

References

1. McGuigan MA, Whyte IM, Dawson AH, Seifert SA, Schonwald S, Yip L, et al. (2004). "125. Vasodilators". In Dart RC (ed.). Medical Toxicology (3rd ed.). Philadelphia [u.a.]: Lippincott Williams & Wilkins. p. 718. ISBN 978-0781728454.
2. Erkert RS, Macallister CG (April 2002). "Isoxsuprine hydrochloride in the horse: a review". Journal of Veterinary Pharmacology and Therapeutics. 25 (2): 81–87. doi:10.1046/j.1365-2885.2002.00386.x. PMID 12000527.
3. Cole C, Bentz B, Maxwell L, eds. (2014). "13. Clinical pharmacology of the equine musculoskeletal system". Equine Pharmacology. Wiley—Blackwell. p. 224. ISBN 978-0-8138-2262-4.
4. Gozo EG, Yebes RB (November 1984). "Hemodynamic effects of isoxsuprine in cardiac failure". Chest. 86 (5): 736–40. doi:10.1378/chest.86.5.736. PMID 6488912.
5. Falkay G, Kovács L (1986). "Affinity of tocolytic agents on human placental and myometrial beta-adrenergic receptors". Journal of Perinatal Medicine. 14 (2): 109–13. doi:10.1515/jpme.1986.14.2.109. PMID 2874205. S2CID 6039919.
6. Giorgino FL, Egan CG (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): 415–20. doi:10.1055/s-0031-1296305. PMID 20712130. S2CID 21297911.
7. "Isoxsuprine". Drugs.com.
8. Forney BC (2007). Equine Medications. The Horse health care library. Lexington, KY: Eclipse Press. OCLC 1360077554.