Hyoscyamine


Hyoscyamine
Hyoscyamine
Systematic (IUPAC) name
(8-methyl-8-azabicyclo[3.2.1]oct-3-yl) 3-hydroxy-2-phenylpropanoate
Clinical data
Trade names Anaspaz, Levbid, Levsin
AHFS/Drugs.com monograph
MedlinePlus a684010
Pregnancy cat. C
Legal status Prescription only (US)
Routes Oral, Injection
Pharmacokinetic data
Bioavailability 50% Protein binding
Metabolism Hepatic
Half-life 3–5 hrs.
Excretion Urine
Identifiers
CAS number 101-31-5 YesY
ATC code A03BA03
PubChem CID 154417
DrugBank DB00424
ChemSpider 10246417 YesY
UNII PX44XO846X YesY
ChEBI CHEBI:17486 N
ChEMBL CHEMBL1697729 N
Chemical data
Formula C17H23NO3 
Mol. mass 289.375 g/mol
SMILES eMolecules & PubChem
 N(what is this?)  (verify)

Hyoscyamine is a tropane alkaloid. It is a secondary metabolite found in certain plants of the Solanaceae family, including henbane (Hyoscyamus niger), mandrake (Mandragora officinarum), jimsonweed (Datura stramonium), tomato (Solanum lycopersicum) and deadly nightshade (Atropa belladonna). It is the levorotary isomer of atropine (third of the three major nightshade alkaloids) and thus sometimes known as levo-atropine. Hyoscyamine should not be confused with hyoscine, an older alternate name for the related nightshade-derived anticholinergic scopolamine.

Brand names for hyoscyamine include Symax, HyoMax, Anaspaz, Buwecon, Cystospaz, Levsin, Levbid, Levsinex, Donnamar, NuLev, Spacol T/S and Neoquess.

Contents

Uses

Hyoscyamine is used to provide symptomatic relief to various gastrointestinal disorders including spasms, peptic ulcers, irritable bowel syndrome, diverticulitis, pancreatitis, colic and cystitis. It has also been used to relieve some heart problems, control some of the symptoms of Parkinson's disease, as well as for control of respiratory secretions in palliative care.[1] It may be useful in pain control for neuropathic pain treated with opioids as it increases the level of analgesia obtained. Several mechanisms are thought to contribute to this effect. The closely related drugs atropine and scopolamine and other members of the anticholinergic drug group like cyclobenzaprine, trihexyphenidyl, and orphenadrine are also used for this purpose. When hyoscyamine is used along with opioids or other anti-peristaltic agents, measures to prevent constipation are especially important given the risk of paralytic ileus.

Side effects

Side effects include dry mouth and throat, eye pain, blurred vision, restlessness, dizziness, arrhythmia, flushing, and faintness. An overdose will cause headache, nausea, vomiting, and central nervous system symptoms including disorientation, hallucinations, euphoria, sexual arousal, short-term memory loss, and possible coma in extreme cases. Some people can experience transient combativeness. The euphoric and sexual effects are stronger than those of atropine but weaker than those of scopolamine, as well as dicycloverine, orphenadrine, cyclobenzaprine, trihexyphenidyl, and ethanolamine antihistamines like phenyltoloxamine.[citation needed]

Pharmacology

Hyoscyamine is an anticholinergic, specifically an antimuscarinic, working by blocking the action of acetylcholine at parasympathetic sites in smooth muscle, secretory glands and the CNS. It also increases cardiac output, dries secretions, and antagonizes serotonin. At comparable doses, hyoscyamine has 98 per cent of the anticholinergic power of atropine. The other major belladonna-derived drug scopolamine has 92 per cent of the antimuscarinic potency of atropine.[citation needed]

Isolation and plant biosynthesis

Hyoscyamine can be extracted from plants of the Solanaceae family, notably Datura stramonium. As hyoscyamine is a direct precursor in the plant biosynthesis of scopolamine, it is produced via the same metabolic pathway.[2]

References

  1. ^ http://www.nlm.nih.gov/medlineplus/druginfo/meds/a684010.html
  2. ^ Ziegler, J; Facchini, PJ (2008). "Alkaloid biosynthesis: metabolism and trafficking.". Annual review of plant biology 59: 735–69. PMID 18251710. 

[Hyoscyamine Sulfate]http://www.medscape.com/druginfo/dosage?drugid=6428&drugname=Hyoscyamine+Sulfate+Oral&monotype=default