Definition
These are drugs, which block the muscarinic receptors.
Classification
A- Natural Alkaloids
Examples:
- Atropine : extracted from Atropa belladonna plant or Datura stramonium plant.
- Scopolamine (L –Hyoscine).
B- SYNTHETIC ESTERS
These are either tertiary amines (lipid soluble and cross the blood brain barrier or quaternary amines (lipid insoluble) and cannot cross the blood brain barrier). They are classified according to their clinical uses into:
Drugs mainly used to treat the manifestations of parkinson’s disease: Benzatropine ,Trihexyphenidyl ,Biperiden.
2Drugs mainly used to produce mydriasis and cycloplegia: Atropine, Homatropine, Eucatropine, Cyclopentolate ,Tropicamide; least duration .
Drugs mainly used to produce bronchodilation: Ipratropium, tiotropium
Drugs mainly used as antisecretory and antispasmodic on the GIT: Hyoscine butylbromide ,Homatropine methyl bromide ,Propantheline
Drugs mainly used for its effect on the genitourinary system: Oxybutynin, Glycopyrrolate ,Emepronium.