NBDE Pharmacology and Therapeutics 5

Question 1

Which alpha-2 adrenergic agonist is used as an adjunct for sedation in dentistry and can cause rebound hypertension upon abrupt withdrawal?

Accepted Answer

Clonidine

Answer

Clonidine acts centrally on alpha-2 receptors to reduce sympathetic outflow; abrupt withdrawal causes rebound hypertension due to sympathetic surge.

Question 2

A patient taking SSRIs (e.g., fluoxetine) is prescribed tramadol for postoperative pain. The PRIMARY concern with this combination is:

Accepted Answer

Serotonin syndrome due to excess serotonergic activity

Answer

Both SSRIs and tramadol increase serotonergic transmission; combining them raises the risk of serotonin syndrome (agitation, hyperthermia, clonus).

Question 3

Which property of a local anesthetic MOST determines its duration of action?

Accepted Answer

Degree of protein binding

Answer

Local anesthetics with higher protein binding (e.g., bupivacaine at ~95%) remain bound to sodium channel proteins longer, extending their duration of action.

Question 4

Vasopressin (felypressin) is used as a vasoconstrictor with prilocaine. Compared to epinephrine, it is PREFERRED in patients with:

Accepted Answer

Severe cardiovascular disease or thyrotoxicosis

Answer

Felypressin acts on V1 receptors without beta-adrenergic stimulation, making it safer in patients with ischemic heart disease or hyperthyroidism.

Question 5

Which drug is used to treat acute narrow-angle glaucoma that can be precipitated by anticholinergic premedications given in dentistry?

Accepted Answer

Pilocarpine eye drops

Answer

Pilocarpine, a cholinergic miotic, reverses pupillary dilation and reduces intraocular pressure in acute angle-closure glaucoma.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Pharmacology and Therapeutics 5