Pharmacology Fundamentals Flashcards

A patient in the PACU develops hypotension following spinal anesthesia. Which vasopressor is the first-line agent for spinal-induced hypotension in obstetric patients?

Answer: Phenylephrine

Phenylephrine is the preferred first-line vasopressor for spinal-induced hypotension in obstetrics because it maintains uteroplacental blood flow better than ephedrine.

Dantrolene is the treatment for malignant hyperthermia. What is its mechanism of action?

Answer: Inhibits calcium release from the sarcoplasmic reticulum via RYR1 receptor

Dantrolene binds the ryanodine receptor (RYR1) on the sarcoplasmic reticulum, blocking the uncontrolled calcium release that drives the hypermetabolic state of MH.

A postoperative patient receives metoclopramide for PONV. Which serious adverse effect must the nurse monitor for?

Answer: Extrapyramidal symptoms

Metoclopramide is a dopamine antagonist that can cause extrapyramidal side effects including akathisia, dystonia, and tardive dyskinesia, especially with repeated dosing.

Which pharmacologic property determines how quickly an inhalational anesthetic is taken up and eliminated from the body?

Answer: Blood/gas partition coefficient

A low blood/gas partition coefficient means the agent is poorly soluble in blood, leading to rapid equilibration and faster onset and offset of anesthesia.

A patient who took monoamine oxidase inhibitors (MAOIs) receives meperidine in the PACU. What life-threatening reaction can occur?

Answer: Serotonin syndrome

The MAOI-meperidine interaction can cause a serotonin syndrome characterized by hyperthermia, agitation, diaphoresis, clonus, and cardiovascular instability.

Ketamine is commonly used for procedural sedation. Which unique hemodynamic property makes it useful in trauma patients with hemorrhagic shock?

Answer: Stimulates catecholamine release, maintaining or increasing blood pressure

Ketamine stimulates sympathetic nervous system activity, causing catecholamine release that maintains or elevates blood pressure, heart rate, and cardiac output.

A patient is transitioning from IV to oral opioids. To safely convert IV morphine 4 mg to oral oxycodone, the nurse knows the oral bioavailability difference requires approximately which conversion?

Answer: IV morphine 4 mg = oral oxycodone 6–8 mg

IV morphine 4 mg converts to approximately 12 mg oral morphine (3:1 ratio), and oral morphine to oral oxycodone is approximately 1:0.67, yielding about 6–8 mg oxycodone.