Antimuscarinic Drugs Flashcards
Atropine (anticholinergic)
- Ocular and CNS applications
- M1/M2/M3 non-selective
- tertiary amine
- Used to treat: GI, urinary conditions, motion sickness, adjunct for parkinsons
Anisotropine
GI tract and peripheral applications
Tertiary Amines
Atropine, scopolamine
Jimsonweed (Datura stramonium)
Naturally occurring tertiary amine
Short acting tertiary amine
homatropine, tropicamide
Parkinson’s disease drug
Benztropine (Generic), Congentin (Trade)
GI Disorder Quaternary Amine
Glycopyrrolate, Propantheline bromide (G) - Probanthine (T)
COPD Quaternary amines
Ipratropium bromide
Scopolamine (long lasting tertiary amine)
• M1/M2/M3 non-selective (drugs will hit all of them)
• Used to treat:
o GI
o Urinary conditions
o Motion sickness
o Adjunct for Parkinsons
• Tertiary compounds affect the CNS. Scopolamine has higher CNS penetration; induces greater drowsiness (low doses) or hallucinations (high doses)
Antimuscarinic Duration of Effect
- Atropine: 7 - 10 days
- Scopolamine: 3 - 7 days
- Homatropine: 1 - 3 days
- Cyclopentolate: 1 day
- tropicamide: 0.25 days
Benzotropine (Cogentin)
[Antimuscarinic]
Tertiary amine used for Parkinson’s Disease
Have sedative activity
Used as an adjunct therapy with L‐DOPA in PD patients (to achieve
better balance between dopaminergic and cholinergic
neurotransmission)
Similar potency to atropine
Glycopyrrolate, Propantheline Bromide (Probanthine)
[Antimuscarinic]
Quaternary Amines used for GI Disorders, CHARGED
Used to treat gastric disorders (GI spasms, peptic ulcers), charged N makes crossing the gut difficult
Ipratropium Bromide
[Antimuscarinic]
Quaternary Amines for COPD, CHARGED
M3 receptors mediate constriction of bronchial smooth muscle
M3 antagonist will block Ach-mediated constriction and open the airways
Less effective as a monotherapy, but enhances the therapeutic effect of beta-adrenergic agonists in COPD
Anticholinergic Toxicity w/ Atropine in relation to dose
0.5mg dose = Slowing of cardiac, dryness of the mouth (paradoxical effect)
1mg dose = acceleration of the heart
> /=10 : Red as a beet (blocked sweat glands, overheating), dry as a bone (dried up secretions), blind as a bat (blocked ciliary muscle), hot as a firestone (no thermoregulation) and mad as a hatter (hallucinating)
