Dental Pharmacology Flashcards

Which local anesthetic has the longest duration of pulpal anesthesia due to its high lipid solubility and protein binding?

Answer: Bupivacaine

Bupivacaine provides the longest duration of pulpal anesthesia (up to 12 hours) because of its high lipid solubility and extensive protein binding.

Articaine is structurally unique among amide local anesthetics because it contains:

Answer: A thiophene ring instead of a benzene ring

Articaine uniquely contains a thiophene ring, which increases its lipid solubility and enables enhanced diffusion through soft and hard tissues.

The maximum recommended dose of epinephrine for a patient with significant cardiovascular disease is:

Answer: 0.04 mg

The American Heart Association recommends limiting epinephrine to 0.04 mg (approximately 2 cartridges of 1:100,000) in patients with cardiovascular compromise.

Which local anesthetic is most associated with methemoglobinemia when used in high doses?

Answer: Prilocaine

Prilocaine is metabolized to ortho-toluidine, which oxidizes hemoglobin to methemoglobin, particularly at high cumulative doses.

Local anesthetics primarily prevent nerve impulse conduction by:

Answer: Blocking voltage-gated sodium channels

Local anesthetics bind to and block voltage-gated sodium channels, preventing sodium influx and stopping action potential propagation along the nerve.

Sodium bisulfite is added to local anesthetic cartridges that contain epinephrine in order to:

Answer: Preserve epinephrine by preventing its oxidation

Sodium bisulfite is an antioxidant that protects epinephrine from oxidative degradation, which is why epinephrine-containing solutions have a lower pH (3.3–5.5).

Epinephrine in local anesthetic solutions acts on which receptors to produce vasoconstriction at the injection site?

Answer: Alpha-1 adrenergic receptors

Vasoconstriction at the injection site is mediated by alpha-1 adrenergic receptor stimulation, which prolongs anesthetic duration and reduces systemic absorption.