Chapter 7. Controlled-Release Local Anesthetics
A. Frequently leads to near-toxic doses of local anesthetic
B. Has a structure consisting of a multilamellar liposome
C. Has a structure consisting of a multivesicular liposome
D. Has a structure consisting of a unilamellar liposome
C is correct. Has a structure consisting of a multivesicular liposome. Each chamber in the multivesicular liposome is separated from adjacent chambers by lipid membranes.
A is incorrect. The DepoFoam delivery system can reduce systemic exposure and toxicity by reducing peak serum levels of a drug.
B and D are incorrect. Multivesicular liposome is distinguished structurally from unilamellar and multilamellar liposomes.
What are some advantages of encapsulating local anesthetics (LAs) in liposomes?
A. Has been shown to be nontoxic and biodegradable
B. Has been shown to consistently release medication over 36 hours
C. LAs are the only medication to be encapsulated in liposomes
D. Stable due to inability to oxidize the lipid bilayer
A is correct. Has been shown to be nontoxic and biodegradable as the liposomes are composed of naturally occurring substances.
B is incorrect. LA in liposomes has not been shown to consistently release medication over 36 hours.
C is incorrect. Multiple hydrophobic and hydrophilic materials have been formulated in liposomes. DepoFoam has been used with cytarabine as DepoCyt(e).
D is incorrect. Liposomes are unstable colloidal systems, due to both their larger physical size and the fact that they are prone to oxidation.
A 56-year-old woman with hypertension, coronary artery disease, diabetes, end stage renal disease, and alcoholic cirrhosis presents for a hemorrhoidectomy. Which of the following clinical considerations is true?
A. Avoid use of liposomal bupivacaine in a patient with previous cardiac disease due to risk of local anesthetic systemic toxicity (LAST).
B. Caution is advised when using liposomal bupivacaine in patients with severe hepatic dysfunction.
C. Caution is advised when using liposomal bupivacaine in patients with severe renal dysfunction.
D. Diabetic nephropathy can lead to a 1.5-fold increase in maximum plasma concentration of liposomal bupivacaine.
B is correct. Caution is advised when using liposomal bupivacaine in patients with severe hepatic dysfunction. A 1.5-fold increase in the maximum plasma concentration was seen ...