Hyoscyamine
Medicinal Chemistry
Molecular Weight
289.37
Molecular Formula
C17H23NO3
IUPAC Name
(8-methyl-8-azabicyclo[3.2.1]oct-3-yl) (2S)-3-hydroxy-2-phenylpropanoate
Pharmacognosy
Biological Source
Hyoscyamus niger, Atropa belladonna
Active Constituents
l-hyoscyamine
Pharmacology & Synthesis
Mechanism of Action
Levorotatory isomer of atropine; potent competitive muscarinic receptor antagonist.
Pharmacokinetics (ADME)
A: Well absorbed from GI tract.
D: Crosses BBB readily.
M: Hepatic hydrolysis.
E: Renal.
Pharmacodynamics
Reduces GI motility and secretions, potent antispasmodic effect.
Synthesis Pathway
Biosynthesized from ornithine and phenylalanine.
Safety, Warnings & Interactions
Adverse Effects
Dry mouth, urinary retention, blurred vision, tachycardia.
Contraindications
Glaucoma, myasthenia gravis, obstructive uropathy.
Drug Interactions
Antacids decrease absorption; additive with other anticholinergics.
Pharmaceutics & Compendia
Dosage Forms
Tablets, Elixir, Injection
Official Compendia
USP