Scopolamine butylbromide

Scopolamine butylbromide (Hyoscine butylbromide) is an orally active anticholinergic agent and spasmolytic. Scopolamine butylbromide binds with high affinity to rat cardiac M2 (K_i 83 nmol/L), hM2 (K_i 233 nmol/L), rat intestinal M3 (K_i 290 nmol/L) and hM3 (K_i 643 nmol/L) muscarinic receptors. Scopolamine butylbromide exerts a dose-dependent antagonistic effect on Carbachol-induced gastrointestinal smooth muscle spasm. Scopolamine butylbromide can be used for the research of abdominal colic and pain associated with gastrointestinal spasm, functional abdominal pain, chronic gastropathy and gastric ulcer^[1][2]. In Vitro:Scopolamine butylbromide binds with high affinity to rat cardiac M2 (K_i 83 nmol/L), hM2 (K_i 233 nmol/L), rat intestinal M3 (K_i 290 nmol/L) and hM3 (K_i 643 nmol/L) muscarinic receptors^[1].
Scopolamine butylbromide specifically inhibits acetylcholine-induced contraction of isolated guinea pig ileum, with a pA₂ value of 7.8; it also slightly inhibits histamine-induced contraction, with a pA₂ value of 4.6^[1].
Scopolamine butylbromide inhibits the contraction of isolated guinea pig colon induced by acetylcholine, transmural stimulation and pelvic nerve stimulation, with ID₅₀ values of 8.13 × 10^-8 mol/L, 1.15 × 10^-7 mol/L and 2.54 × 10^-7 mol/L, respectively. It also reduces acetylcholine release from stimulated nerves^[1].
Scopolamine (0.1-800 μg/mL) butylbromide inhibits transmural stimulation-induced contraction and pressure-induced peristalsis of isolated guinea pig ileum at concentrations of 0.1-0.6 μg/mL and 4-6 μg/mL; however, due to limited tissue penetration, a dose of 600-800 μg/mL is required when administered via the mucosa^[1]. In Vivo:Scopolamine (intravenous injection) butylbromide exhibits a dose-dependent antagonistic effect on carbachol-induced gastrointestinal smooth muscle spasm in anesthetized rats^[1].
Scopolamine (0.1-30 mg/kg; p.o.; single administration) butylbromide displaces ≥50% of the radioligand bound to muscarinic receptors in rat duodenal smooth muscle at doses of 0.1-3.0 mg/kg, whereas a dose of ≥30 mg/kg is required to achieve similar displacement in myocardium^[1].
Scopolamine (3.0 μg/kg; intraduodenal administration; single dose) butylbromide and (0.25-50 mg/kg; intravenous injection; single dose) inhibits spontaneous and electrical stimulation-induced duodenal motility in anesthetized dogs^[1].
Scopolamine (intravenous injection) butylbromide reduces pelvic nerve-induced colonic contractions in anesthetized guinea pigs in a dose-dependent manner, with an ED₅₀ of 26 μg/kg and a relative potency of 16.4^[2].