CHAPTER 7 DRUGS WITH CHOLINOMIMETIC EFFECTS Flashcards
DIRECT-ACTING CHOLINE ESTERS
Muscarinic agonist
* negligible effect at
nicotinic receptors
* Postoperative and
neurogenic ileus and
urinary retention
Bethanechol
DIRECT-ACTING CHOLINE ESTERS
* Nonselective muscarinic and nicotinic agonist; otherwise similar to bethanechol; used topically almost exclusively for glaucoma
Carbachol
DIRECT-ACTING MUSCARINIC ALKALOIDS OR SYNTHETICS
- Like bethanechol, partial
agonist
- Glaucoma; Sjögren’s
syndrome
Pilocarpine
DIRECT-ACTING NICOTINIC AGONISTS
- Agonist at both NN and
NM receptors
- Medical use in smoking
cessation
- Nonmedical
use in smoking and in
insecticides
Nicotine
SHORT-ACTING CHOLINESTERASE INHIBITOR (ALCOHOL)
- Alcohol, binds briefly
to active site of
acetylcholinesterase
(AChE) and prevents
access of acetylcholine
(ACh)
- Diagnosis and acute
treatment of myasthenia
gravis
Edrophonium
INTERMEDIATE-ACTING CHOLINESTERASE INHIBITORS (CARBAMATES)
- Forms covalent bond with
AChE, but hydrolyzed and
released
- Myasthenia gravis
* postoperative and
neurogenic ileus and
urinary retention
Neostigmine
Like neostigmine, but longer-acting (4–6 h); used in myasthenia
Pyridostigmine
Like neostigmine, but natural alkaloid tertiary amine; enters CNS
Physostigmine
LONG-ACTING CHOLINESTERASE INHIBITORS (ORGANOPHOSPHATES)
- Like neostigmine, but
released more slowly
- Obsolete * was used in
glaucoma
Echothiophate
Insecticide, relatively safe for mammals and birds because metabolized by other enzymes to inactive products; some medical use as ectoparasiticide
Malathion
Insecticide, dangerous for all animals; toxicity important because of agricultural use and exposure of farm workers
Parathion, others
Nerve gas,” used exclusively in warfare and terrorism
Sarin, others
