Ganglionic Stimulants Quiz and Flashcards: Pharmacology Study

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Questions and Answers

What are the two types of ganglia that drugs can act on, and what effects can they produce?

Sympathetic and parasympathetic ganglia; stimulation or blockade

Name two selective nicotinic agonists that act on ganglia.

Nicotine, Dimethyl phenyl piperazinium (DMPP)

What is the mechanism of action of nicotine in autonomic ganglia at low dosage?

Stimulates nicotinic receptor, enhances sympathetic and parasympathetic neurotransmission

What effect does prolonged exposure to high dosage of nicotine have on autonomic ganglia?

Depolarising blockade of ganglia Signup and view all the answers

What is the mechanism of action of nicotine on the adrenal medulla?

Small doses evoke the discharge of CAs, while larger doses prevent their release. Signup and view all the answers

What are the pharmacological effects of nicotine on the cardiovascular system?

Stimulation of sympathetic ganglia, vasoconstriction (α stimulation), increased BP, and tachycardia. Signup and view all the answers

How does nicotine affect the gastrointestinal tract?

Nicotine results in increased tone and motor activity of the bowel, leading to nausea, vomiting, and occasionally diarrhea. Signup and view all the answers

What are the pharmacological actions of nicotine at the neuromuscular junction (NMJ)?

Nicotine has a biphasic action, with small doses causing a stimulant effect and large doses leading to receptor desensitization and inhibition of muscle contraction. Signup and view all the answers

What are the effects of ganglionic blocking drugs on the cardiovascular system?

Vasodilation, increased blood flow, hypotension, dilation, pooling of blood, decreased preload, and decreased cardiac output. Signup and view all the answers

What are the goals of pharmacotherapy for smoking cessation?

To reduce the craving for the satisfying effects of nicotine and to suppress the physical withdrawal symptoms of nicotine. Signup and view all the answers

Name two drugs currently utilized for reducing the craving for nicotine and suppressing physical withdrawal symptoms.

Nicotine, Varenicline, Antidepressant (Bupropion) Signup and view all the answers

What distinguishes the stimulation of ganglia by tetramethylammonium (TMA) or 1,1dimethyl-4-phenylpiperazinium iodide (DMPP) from that produced by nicotine?

Initial stimulation by TMA and DMPP is not followed by dominant blocking action, unlike nicotine. Signup and view all the answers

What are the pharmacological effects of higher levels of nicotine in the central nervous system?

Convulsion, coma Signup and view all the answers

What are the ganglionic blocking effects on the iris and ciliary muscles?

Mydriasis, cycloplegia (cholinergic) Signup and view all the answers

What are the predominant tones affected by ganglionic block in the arterioles and veins?

Arterioles: Sympathetic (adrenergic), Veins: Sympathetic (adrenergic) Signup and view all the answers

Name two ganglionic blocking drugs.

Trimethaphan, Mecamylamine Signup and view all the answers

Study Notes

Autonomic Ganglia

Autonomic ganglia can be divided into two types: sympathetic and parasympathetic
Drugs can act on both types of ganglia to produce various effects

Nicotinic Agonists

Two selective nicotinic agonists that act on ganglia: dimethylphenylpiperazinium (DMPP) and tetramethylammonium (TMA)

Mechanism of Action of Nicotine

At low doses, nicotine stimulates autonomic ganglia, releasing acetylcholine and producing excitatory effects
Prolonged exposure to high doses of nicotine can lead to desensitization and inhibition of autonomic ganglia

Effect on Adrenal Medulla

Nicotine stimulates the adrenal medulla to release epinephrine, leading to increased glucose levels and vasoconstriction

Cardiovascular Effects

Nicotine increases heart rate, blood pressure, and cardiac output due to stimulation of sympathetic ganglia
Nicotine can also cause vasoconstriction, leading to increased blood pressure

Gastrointestinal Effects

Nicotine can stimulate the gastrointestinal tract, increasing motility and tone

Neuromuscular Junction (NMJ)

Nicotine can stimulate the NMJ, increasing muscle contraction force and hastening fatigue

Ganglionic Blocking Drugs

Ganglionic blocking drugs can lower blood pressure, decrease heart rate, and reduce cardiac output
Examples of ganglionic blocking drugs: hexamethonium and mecamylamine

Pharmacotherapy for Smoking Cessation

Goals of pharmacotherapy: reduce craving, suppress physical withdrawal symptoms, and manage nicotine withdrawal syndrome
Examples of drugs used for smoking cessation: varenicline and bupropion

Higher Levels of Nicotine in the CNS

Higher levels of nicotine in the CNS can cause stimulatory effects, including increased alertness and arousal

Ganglionic Blocking Effects on the Iris and Ciliary Muscles

Ganglionic blockade can cause mydriasis (pupil dilation) and cycloplegia (temporary paralysis of the ciliary muscle)

Predominant Tones Affected by Ganglionic Block

Ganglionic blockade can decrease sympathetic tone and increase parasympathetic tone in arterioles and veins

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Description

Test your knowledge about drugs that act on sympathetic and parasympathetic ganglia, producing either stimulation or blockade. This quiz covers selective nicotinic agonists, nonselective/muscarinic agonists, and the mechanism of action of nicotine as a ganglionic stimulant.

Ganglionic Stimulants Quiz

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