Urapidil hydrochloride

Description

Urapidil is an antagonist of α₁-adrenergic receptors (α₁-ARs) and a partial agonist of the serotonin (5-HT) receptor subtype 5-HT_1A. It selectively binds to α₁- over α₂-ARs (IC₅₀s = 0.74 and 42 μM, respectively) and to 5-HT_1A over 5-HT_1B and 5-HT₂ receptors (IC₅₀s = 0.4, 20.4, and >10 μM, respectively) in rat cortex. Urapidil inhibits cAMP accumulation induced by forskolin in calf hippocampus as a functional model for 5-HT_1A receptors (EC₅₀ = 390 nM). It is also a β₁-AR antagonist that inhibits the positive chronotropic response induced by isoproterenol in isolated rat atria (pA₂ = 6.05). Urapidil (1 μmol/kg, i.v.) lowers mean arterial pressure (MAP) in anesthetized cats, an effect that is reduced by central administration of the 5-HT_1A receptor antagonist spiroxatrine.

Chemical Properties

White to Off-White Crystalline Powder

Uses

Antihypertensive;Serotonergic receptor agonist

Uses

α1-Adrenergic antagonist; derivative of Uracil (U801000). Antihypertensive.

Uses

a1-Adrenergic antagonist; derivative of Uracil. Antihypertensive

Biological Activity

α 1 -adrenoceptor antagonist and 5-HT 1A receptor agonist (pIC 50 values are 6.13 and 6.4 respectively). Clinically used hypotensive agent.

Side effects

Side effects that may occur during treatment with uradil antihypertension include dizziness, fatigue, nausea, and light-headedness effects. The increases in systolic blood pressure heart rate caused by three progressive work loads bicycle exercise were not affected during urapidil, A slight reduction in forced expiratory volume was observed in some patients during treatment with beta-blocker. There was no case orthostatic hypotension during urapidil administration, despite its alpha1-blocking action. Side-effects were rare negligible^[1].

References

[1] G LEONETTI. Comparison of the antihypertensive effect of urapidil and metoprolol in hypertension.[J]. European Journal of Clinical Pharmacology, 1986, 30 6: 637-640. DOI:10.1007/BF00608208.