Cholinergic agonists (direct and indirect) — Flashcards

Flashcard 1: Rank the following receptors for affinity to **norepinephrine**, from highest to lowest: α1, β1, β2

Answer: α1 > β1 > β2

Extra: Norepinephrine is a potent agonist at α1, α2, and β1 receptors, but has negligible activity at β2 receptors. Contrast this with Epinephrine, which has significant activity at all four receptors (α1, α2, β1, β2).

Flashcard 2: What drug class does pilocarpine belong to? _____

Answer: Cholinomimetics (muscarinic agonists)

Flashcard 3: The vestibular system contains _____ muscarinic receptors

Answer: M1

Flashcard 4: Which drug class is used to reverse the effects of neuromuscular junction blockade?_____

Answer: Acetylcholinesterase inhibitors (e.g. neostigmine)

Flashcard 5: Does atropine reverse the flaccid paralysis associated with cholinesterase inhibitor poisoning? _____

Answer: No, only effective at muscarinic receptors

Flashcard 6: Mechanism and primary obstetric use of Terbutaline?

Answer: Select β2 agonist used as a tocolytic to delay premature labor.

Extra: Terbutaline is a selective β2-adrenergic agonist. By stimulating β2 receptors in the uterus, it causes smooth muscle relaxation, helping to suppress premature uterine contractions (tocolysis).

Flashcard 7: Main indication and mechanism of Tamsulosin?

Answer: α1-antagonist selective for prostatic receptors (BPH treatment)

Extra: Mechanism: Inhibits smooth muscle contraction in the prostatic urethra and bladder neck. Unlike non-selective α-blockers, it has less effect on systemic blood pressure.

Flashcard 8: What is the clinical use and mechanism of Donepezil?

Answer: Used in Alzheimer's disease; Reversible Acetylcholinesterase (AChE) inhibitor

Extra: Mechanism: Centrally acting reversible acetylcholinesterase inhibitor. Indication: First-line treatment for Alzheimer's disease. Side effects: Nausea, dizziness, insomnia, bradycardia.

Flashcard 9: What is the mechanism and primary clinical use of Galantamine?

Answer: Cholinesterase inhibitor used in Alzheimer's disease

Extra: Mechanism: Reversible, competitive acetylcholinesterase inhibitor (AChEI). It may also modulate nicotinic acetylcholine receptors. Indication: Mild-to-moderate Alzheimer's disease. Side effects: Nausea, dizziness, insomnia.

Flashcard 10: What is the mechanism and primary clinical use of Rivastigmine?

Answer: Acetylcholinesterase inhibitor used in Alzheimer's disease and Parkinson's disease dementia.

Extra: Mechanisms: Reversible inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Side effects: Nausea, dizziness, insomnia. Available as a transdermal patch to reduce GI side effects.