Characterization of the oxybutynin antagonism of drug-induced spasms in detrusor.

Abstract

Oxybutynin chloride exerts a moderate anticholinergic effect on rabbit detrusor in vitro, which is reversible and competitive in nature (KB = 4.7 x 10(-9), and midway in potency between atropine and papaverine. In addition, oxybutynin strongly antagonizes BaCl2-induced spasms of detrusor with a potency equivalent to that of papaverine and 10 times that of atropine. This musculotropic spasmolytic effect is slightly greater in rabbit than human or monkey tissue, and noncompetitive (pD2 = 5.5). This direct relaxant effect, unlike that of papaverine, is not mediated by the inhibition of tissue phosphodiesterase, but probably reflects oxybutynin's local anesthetic properties and associated effects on Ca++ fluxes and binding.

• Authors: G F Anderson, C M Fredericks
• Journal: Pharmacology (Pharmacology) Vol. 15 Issue 1 Pg. 31-9 ( 1977) ISSN: 0031-7012 [Print] Switzerland
• PMID: 190623 (Publication Type: Journal Article)

Chemical References

• Cyclohexanes
• Diethylamines
• Mandelic Acids
• Parasympatholytics
• Phosphodiesterase Inhibitors
• Barium
• Carbachol

Topics

• Animals
• Barium (antagonists & inhibitors)
• Carbachol (antagonists & inhibitors)
• Cyclohexanes (pharmacology)
• Diethylamines (pharmacology)
• Dose-Response Relationship, Drug
• Humans
• In Vitro Techniques
• Mandelic Acids (pharmacology)
• Muscle, Smooth (drug effects)
• Parasympatholytics
• Phosphodiesterase Inhibitors
• Rabbits
• Urinary Bladder (drug effects)