Direct Acting cholinomimetics Flashcards
What drug class is bethanechol?
muscarinic cholinergic receptor agonist
work on postsynaptic membrane of the target tissue to directly stimulate a parasympathetic nervous system response
What is the mechanism of action of bethanechol?
Directly stimulates muscarinic receptors, enhancing smooth muscle contraction
Cholinergic stimulation to the GI tract & urinary system is excitatory
What conditions is bethanechol used to treat?
Urinary retention, postoperative ileus
It is indicated for GI and urinary bladder paralysis
What systemic effects can bethanechol induce?
- Diarrhea
- Incontinence
- Bradycardia
- Hypotension
- Bronchoconstriction
- Exacerbation of asthma
CANNOT be used when patient has a GI or urinary obstruction
What drug class is pilocarpine?
muscarinic cholinergic receptor agonist
work on postsynaptic membrane of the target tissue to directly stimulate a parasympathetic nervous system response
What is the action of pilocarpine?
stimulates muscarinic receptor on the ciliary muscle to contract ciliary muscle,
constricts the pupil
and then relieve pressure in eye by relaxing schlemm’s canal which allows for reabsorption of the aqueous humor, reducing intraocular pressure
What condition is pilocarpine used to treat?
Glaucoma (reduces intraocular pressure)
Pilocarpine helps in cases where Schlemm’s canal is blocked
What drug class is nicotine?
nicotinic N receptor agonist
binds to the nicotinic cholinergic Nn receptor on the post synpatic membrane of the post synaptic neuron (both in SNS and PNS)
What is the primary action of nicotine?
Binds to nicotinic receptors in the CNS and autonomic ganglia, mimicking acetylcholine
It binds to the nicotinic cholinergic Nn receptor on the postsynaptic membrane
What are the therapeutic uses of nicotine?
Cigarette withdrawal symptoms, nicotine replacement therapy for smoking cessation
What is the primary action of varenicline?
Reduces cravings for and decreases the pleasure effects of cigarettes
What is a key indication for varenicline?
Smoking cessation
What class of drug is varenicline?
nicotinic partial agonist
How are effects of direct acting cholinomimetics different than ACh binding?
DA cholinomimetics effects last longer than Ach at receptor, but the effect is the same
