Opioids - From Apex

Question 1

Describe some differences between epidurally administered hydrophilic opioids and lipophilic opioids

Answer 1

Epidural-administered hydrophilic opioids (eg, morphine, hydromorphone) have:
a slower onset,
a longer duration of action,
a higher incidence of adverse effects,
delayed respiratory depression,
an extensive cerebrospinal fluid spread,
and delayed onset of analgesia compared with lipophilic opioids (eg, fentanyl).

This is mainly because of the low lipid solubility of hydrophilic opioids.

Question 2

Both drug receptor affinity and efficacy are determined by its?

Answer 2

The stereochemistry of the macromolecule determines the binding, based on the specificity of the drug–receptor complex and directs the response in the body.

The role of lipid solubility, ionization, and protein binding are important in the formation of the specific macromolecule to allow the drug to diffuse across cell membranes as a bioavailable compound.

Question 3

Patients taking daily steroids that exceed the equivalent of ______ of prednisone per day longer than _____ require corticosteroid supplementation during the preoperative period. Why?

Answer 3

equivalent of 20 mg of prednisone per day for longer than 3 weeks require corticosteroid supplementation during the perioperative period.

Administration of chronic exogenous steroids suppresses the adrenal glands and may blunt cortisol hypersecretion during stressful events.

Question 4

What is the site of action of intrathecal opioids?

Answer 4

Intrathecal opioids act centrally by diffusion into the spinal cord and interact with mu receptors in the substantia gelatinosa in the dorsal horn.

Question 5

Which high-affinity binding site in the brain is responsible for gabapentin action?

Answer 5

Gabapentin is indicated for the treatment of partial-onset seizures, neuropathic pain, fibromyalgia, postherpetic neuralgia, and painful diabetic neuropathy. Gabapentin binds with the α2-delta subunit of calcium channels.

Question 6

Which synthetic opioid has the LONGEST context-sensitive half-time after a 90-minute infusion?
A. Alfentanil
B. Fentanyl
C. Remifentanil
D. Sufentanil

Answer 6

B. Fentanyl
Following a 90–120 minute infusion of fentanyl, alfentanil, remifentanil, and sufentanil, fentanyl has the longest context-sensitive half-time.

Question 7

Which synthetic opioid has the LONGEST context-sensitive half-time after a 90-minute infusion?
A. Alfentanil
B. Fentanyl
C. Remifentanil
D. Sufentanil

Answer 7

B. Fentanyl
Following a 90–120 minute infusion of fentanyl, alfentanil, remifentanil, and sufentanil, fentanyl has the longest context-sensitive half-time.