Pharmacology of Sedative Agents Flashcards

Which pharmacokinetic property makes remifentanil unique among opioids used in sedation?

Answer: It is broken down by plasma and tissue esterases, giving an ultra-short, context-insensitive half-life

Remifentanil is hydrolyzed by non-specific esterases in blood and tissues, giving a consistent half-life of ~3 minutes regardless of infusion duration.

A patient with COPD requires procedural sedation. Which agent is MOST appropriate due to its minimal effect on respiratory drive?

Answer: Dexmedetomidine

Dexmedetomidine provides sedation with minimal respiratory depression, making it a safer choice in patients with underlying pulmonary disease.

The dose of naloxone to reverse opioid-induced respiratory depression in adults is typically:

Answer: 0.4–2 mg IV, titrated in 0.04 mg increments as needed

Naloxone is given in small incremental doses (0.04 mg IV) titrated to restore adequate respiration while avoiding complete reversal and acute pain.

Which sedative agent is most associated with causing phlebitis and pain on injection when given peripherally due to its propylene glycol vehicle?

Answer: Diazepam

Diazepam formulated in propylene glycol causes significant pain on injection and phlebitis, which is a key reason midazolam replaced it for conscious sedation.

In a patient with liver failure, which pharmacokinetic change is MOST expected with benzodiazepine administration?

Answer: Prolonged sedation due to reduced hepatic metabolism

Benzodiazepines are hepatically metabolized; liver failure reduces clearance and prolongs the drug's effect, requiring significant dose reductions.

Which of the following correctly describes the difference between physical dependence and tolerance regarding sedative agents?

Answer: Dependence means withdrawal symptoms occur on abrupt cessation; tolerance means higher doses are needed for the same effect

Physical dependence manifests as withdrawal on abrupt cessation, while tolerance refers to the need for increasing doses to achieve the same pharmacologic effect.

When titrating sedation agents, the goal of 'minimal sedation (anxiolysis)' is best described as:

Answer: Patient alert, responds normally to verbal commands, cognitive function slightly impaired

Minimal sedation (anxiolysis) means the patient is calm and cooperative, responds normally to commands, but may have mild cognitive or coordination impairment.