Isoxsuprine (hydrochloride)

Isoxsuprine is an adrenergic receptor modulator that has α-adrenergic receptor (α-AR) antagonist and β-AR agonist properties.^1,2 It induces vasodilation of isolated equine common digital artery strips precontracted with norepinephrine, indicating an α-AR effect, and induces relaxation of isolated fowl cecum, an effect that can be blocked by the β-AR antagonist propranolol (Item Nos. 23349 | 17291).^2,3 Isoxsuprine has antinociceptive effects in an acetic acid writhing test in mice.⁴ It also inhibits oxytocin-induced contractions in isolated rat uterus (IC₅₀ = 9.15 µM).⁵ It delays labor onset in rats by 31.63 hours when administered at a dose of 10 mg/kg per day on days 13 to 21 of gestation but increases heart rate with increasing concentration.

WARNING This product is not for human or veterinary use.

1. Cook, P., and James, I. Cerebral vasodilators (second of two parts). N. Engl. J. Med. 305(26), 1560-1564 (1981).

2. Belloli, C., Carcano, R., Arioli, F., et al. Affinity of isoxsuprine for adrenoreceptors in equine digital artery and implications for vasodilatory action. Equine Vet. J. 32(2), 119-124 (2000).

3. Ekert, R.S., and Macallister, C.G. Isoxsuprine hydrochloride in the horse: A review. J. Vet. Pharmacol. Ther. 25(2), 81-87 (2002).

4. Bentley, G.A., and Starr, J. The antinociceptive action of some β-adrenoceptor agonists in mice. Br. J. Pharmacol. 88(3), 515-521 (1988).

5. Viswanathan, C.L., Kodgule, M.M., and Chaudhari, A.S. Design, synthesis and evaluation of racemic 1-(4-hydroxyphenyl)-2-[3-(substituted phenoxy)-2-hydroxy-1-propyl]amino-1-propanol hydrochlorides as novel uterine relaxants. Bioorg. Med. Chem. Lett. 15(15), 3532-3535 (2005).