Pharmacology Flashcards

Which benzodiazepine property makes it ideal for producing anterograde amnesia in dental sedation?

Answer: GABA-A receptor binding, which disrupts hippocampal memory consolidation

Benzodiazepines potentiate GABA-A in the hippocampus, disrupting the transfer of short-term to long-term memory (anterograde amnesia) - a key benefit in dental anxiety management.

A patient receiving an IV opioid develops pinpoint pupils (miosis). This finding is caused by:

Answer: Opioid-induced Edinger-Westphal nucleus stimulation causing pupillary constriction

Opioids stimulate the oculomotor nucleus (Edinger-Westphal), increasing parasympathetic tone to the iris sphincter, causing pupillary constriction (miosis).

The clinical relevance of a drug context-sensitive half-life in dental sedation is:

Answer: It predicts recovery time better than elimination half-life for infusions, as it accounts for drug redistribution

Context-sensitive half-life predicts how long a drug remains clinically active after an infusion - it can increase with infusion duration for some drugs (e.g., fentanyl) due to tissue accumulation.

Which statement correctly describes the pharmacology of ketamine at low (sub-anesthetic) doses?

Answer: It provides analgesia and mild sedation (dissociative analgesia) via NMDA antagonism

Low-dose ketamine (0.1 to 0.5 mg/kg IV) produces dissociative analgesia via NMDA antagonism, enhancing analgesia without full anesthesia, and preserving airway reflexes.

Methemoglobinemia as a complication of local anesthetic use is MOST associated with:

Answer: Benzocaine (topical) and prilocaine at high doses

Benzocaine and prilocaine can oxidize hemoglobin iron from Fe2+ to Fe3+ (methemoglobin), reducing oxygen-carrying capacity and causing cyanosis.

Which pharmacological characteristic explains why IV midazolam has a faster onset than orally administered midazolam?

Answer: IV administration bypasses gastrointestinal absorption and first-pass hepatic metabolism

IV midazolam enters systemic circulation immediately without GI absorption delays or hepatic first-pass metabolism, producing onset within 1 to 3 minutes vs. 15 to 20 minutes orally.