DAANCE Pharmacology 3

Question 1

Opioid-induced nausea and vomiting occurs primarily through stimulation of which brain region?

Accepted Answer

Chemoreceptor trigger zone (CTZ) in the area postrema

Answer

Opioids stimulate dopaminergic and serotonergic receptors in the area postrema chemoreceptor trigger zone, activating the vomiting center.

Question 2

Which drug class interaction is the basis of serotonin syndrome risk when combining certain pain medications?

Accepted Answer

Serotonin-increasing drugs (SSRIs, MAOIs, meperidine) combined causing serotonergic excess

Answer

Serotonin syndrome results from excessive serotonergic activity - combining SSRIs, MAOIs, meperidine, tramadol, or triptans increases serotonin to toxic levels.

Question 3

A ceiling effect for analgesia at higher doses is a characteristic of which drug class?

Accepted Answer

Partial mu-opioid agonists (buprenorphine)

Answer

Partial agonists like buprenorphine produce a ceiling analgesic effect - beyond a dose threshold, increasing the dose adds no further analgesia but does increase side effects.

Question 4

The anticholinergic drug atropine, when given for emergency bradycardia, works by:

Accepted Answer

Blocking muscarinic receptors, removing vagal inhibition of SA node automaticity

Answer

Atropine blocks cardiac muscarinic (M2) receptors, preventing vagal acetylcholine from slowing the SA node, thereby increasing heart rate.

Question 5

Nitrous oxide diffuses into closed gas-containing body spaces faster than nitrogen exits because:

Accepted Answer

Nitrous oxide is approximately 34 times more blood-soluble than nitrogen, allowing rapid diffusion

Answer

N2O high blood-gas solubility coefficient means it transfers rapidly from blood into gas-filled spaces, expanding them. This is why N2O is contraindicated with bowel obstruction, pneumothorax, and middle ear surgery.

DAANCE - Dental Anesthesia Assistant National Certification Examination Practice Test

DAANCE - Dental Anesthesia Assistant National Certification Examination Practice Test

DAANCE Pharmacology 3