Adrenergic receptor subtypes — Flashcards

Flashcard 1: Which adrenergic receptor is sympatholytic? _____

Answer: $\alpha_2$ (Alpha-2) receptor

Extra: $\alpha_2$ receptors are presynaptic G_i-coupled receptors that provide negative feedback, inhibiting further norepinephrine release.

Flashcard 2: Which type of acetylcholine receptors (muscarinic or nicotinic) are found in effector tissues (e.g., heart, smooth muscle, brain, and glands)?

Answer: Muscarinic

Flashcard 3: Phenylephrine is primarily an _____ (alpha 1 or 2) agonist

Answer: 1

Flashcard 4: 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 5: The _____ muscarinic receptor is found in glands, the bladder, and smooth muscle

Answer: M3

Flashcard 6: Mirtazapine is a selective _____ adrenergic antagonist

Answer: alpha-2

Flashcard 7: 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 8: 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 9: 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 10: 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.