Pharmacology of Cholinomimetic Agents

Physostigmine is primarily used for treating glaucoma.

Varenicline is the lipid-soluble cholinomimetic used to facilitate smoking cessation.

Neostigmine is the drug with these characteristics.

<p>Cholinomimetic agents mimic the effects of acetylcholine at cholinergic receptors.</p> Signup and view all the answers

<p>Bethanechol increases gastrointestinal motility.</p> Signup and view all the answers

<p>Direct-acting cholinomimetics stimulate receptors directly, while indirect-acting inhibitors increase acetylcholine availability.</p> Signup and view all the answers

<p>Drugs causing miosis primarily facilitate aqueous humor outflow and lower intraocular pressure.</p> Signup and view all the answers

<p>Decreased neuromuscular transmission is advantageous during surgical anesthesia.</p> Signup and view all the answers

<p>The key physiological responses include decreased heart rate, increased glandular secretion, and contraction of smooth muscles.</p> Signup and view all the answers

<p>Gq protein coupling activates phospholipase C, which leads to the release of diacylglycerol (DAG) and inositol trisphosphate (IP3).</p> Signup and view all the answers

<p>Nn receptors are neuronal nicotinic receptors located in autonomic ganglia, while Nm receptors are muscle nicotinic receptors found at the neuromuscular junction.</p> Signup and view all the answers

<p>The classes of cholinergic agonists include direct-acting agonists, which stimulate muscarinic receptors, and indirect-acting agonists, which inhibit acetylcholinesterase.</p> Signup and view all the answers

<p>Common side effects may include excessive salivation, bradycardia, diarrhea, and increased bronchial secretions.</p> Signup and view all the answers

<p>A major contraindication is the presence of asthma or chronic obstructive pulmonary disease (COPD).</p> Signup and view all the answers

<p>All autonomic ganglia contain nicotinic receptors.</p> Signup and view all the answers

<p>Effector organs influenced include cardiac and smooth muscles, gland cells, and nerve terminals.</p> Signup and view all the answers

<p>Ganglion-blocking drugs cause marked reduction of motility and may lead to severe constipation.</p> Signup and view all the answers

<p>Moderate mydriasis and cycloplegia are signs of atropine overdose affecting the eye.</p> Signup and view all the answers

<p>They may result in some bronchodilation but with little overall effect.</p> Signup and view all the answers

<p>Moderate tachycardia and a reduction in cardiac output at rest can be expected.</p> Signup and view all the answers

<p>They result in reduced contractility of the bladder and impaired ejaculation.</p> Signup and view all the answers

<p>Hyperthermia is one of the most dangerous effects in infants and toddlers.</p> Signup and view all the answers

<p>Antinicotinic drugs may reduce nicotine craving.</p> Signup and view all the answers

<p>Atropine leads to a reduction in gastric secretion.</p> Signup and view all the answers

<p>Skeletal muscle weakness and parasympathetic effects characterize cholinergic crisis.</p> Signup and view all the answers

<p>A muscarinic agonist is a cholinomimetic drug that binds to muscarinic receptors, primarily mimicking the actions of muscarine.</p> Signup and view all the answers

<p>Direct-acting cholinomimetics bind and activate cholinoceptors, whereas indirect-acting cholinomimetics inhibit acetylcholinesterase to enhance acetylcholine's effects.</p> Signup and view all the answers

<p>Parasympathomimetic refers to drugs that produce effects similar to stimulating the parasympathetic nervous system.</p> Signup and view all the answers

<p>Organophosphate aging is the chemical modification of organophosphate after it binds to cholinesterase, resulting in stronger binding to the enzyme.</p> Signup and view all the answers

<p>EDRF, primarily nitric oxide (NO), acts as a potent vasodilator released from vascular endothelial cells.</p> Signup and view all the answers

<p>Choline esters are cholinomimetic drugs composed of choline and an acidic substance, which typically results in poor lipid solubility due to their charged nature.</p> Signup and view all the answers

<p>Cholinomimetic alkaloids are usually lipid-soluble, unlike choline esters, which are typically poorly lipid-soluble.</p> Signup and view all the answers

<p>Cholinoceptor antagonists block receptors, while cholinesterase regenerators act as chemical antagonists of acetylcholinesterase inhibitors.</p> Signup and view all the answers

<p>Antimuscarinic drugs can be M1-selective or nonselective, with atropine as an example of a nonselective antagonist.</p> Signup and view all the answers

<p>Atropine is classic due to its widespread use and ability to block all muscarinic receptor subtypes effectively.</p> Signup and view all the answers

<p>Atropine's lipid-soluble nature, due to it being a tertiary amine, allows it to easily cross membrane barriers.</p> Signup and view all the answers

<p>The two subclasses are muscarinic antagonists and nicotinic antagonists, targeting muscarinic and nicotinic receptors, respectively.</p> Signup and view all the answers

<p>Oximes, such as pralidoxime, are cholinesterase regenerators that reverse the effects of organophosphate inhibitors of acetylcholinesterase.</p> Signup and view all the answers

<p>Selectivity allows for targeted therapeutic effects and minimizes side effects, enhancing clinical outcomes.</p> Signup and view all the answers

<p>Ganglion blockers inhibit transmission at autonomic ganglia, affecting both sympathetic and parasympathetic systems.</p> Signup and view all the answers

<p>Drug X caused a 50 mm Hg rise in mean blood pressure.</p> Signup and view all the answers

<p>There was no blood pressure change in the ganglion-blocked animal.</p> Signup and view all the answers

<p>Drug X caused a 75 mm mean blood pressure rise in the atropine-pretreated animal.</p> Signup and view all the answers

<p>Pralidoxime acts to regenerate active cholinesterase by binding to organophosphate inhibitors.</p> Signup and view all the answers

<p>The oxime group of pralidoxime binds to the phosphorus atom, displacing the inhibitor.</p> Signup and view all the answers

<p>The oxime group's affinity must exceed that of the inhibitor for effective regeneration before aging occurs.</p> Signup and view all the answers

<p>Nicotine typically causes increased blood pressure, while Drug X caused varied effects based on pretreatment.</p> Signup and view all the answers

<p>The substances involved may lead to reductions in salivation, lacrimation, sweating, and gastric secretion.</p> Signup and view all the answers