Opiod Agonists and Antagonists

Question 1

List opioids from most to least potent

Answer 1

Sufentanil > Remi = Fentanyl > Alfentanil > Hydromorphone

> Morphine > Meperidine

Question 2

What opioids have active metabolites?

Answer 2

• Morphine
• Meperidine
• caution use in its w/ renal failure

Question 3

What drug is associated with anticholinergic side effects?

Answer 3

• meperidine

- causes mydriasis, elevates HR, and dry mouth

Question 4

What is important about normeperidine in regards to seizures?

Answer 4

• it causes myoclonus and lowers the seizure threshold

Question 5

Meperidine is a weak serotonin reuptake inhibitor and must be avoided with what type of drugs to avoid serotonin syndrome?

Answer 5

• MAOI (phenelzine, isocarboxazid, tranylcypromine)

Question 6

What drug reduces post shivering?

Answer 6

• meperidine

- d/t kappa stimulation

Question 7

What opioids cause histamine release?

Answer 7

• morphine
• meperidine
• codeine
• oxycodone

Question 8

What does alfentanil have a fast onset?

Answer 8

• 89% of the drug is unionized d/t it’s pKa of 6.5

Question 9

What medications can be given to treat opioid induced hyperalgesia from remifentanil?

Answer 9

• ketamine

- Magnesium sulfate

Question 10

Methadone decreases pain by what 3 mechanisms?

Answer 10

• mu receptor agonist
• NMDA antagonist
• Inhibits reuptake of monoamines in the synaptic cleft

Question 11

How does methadone affect the EKG?

Answer 11

• it prolongs the QT

- can lead to torsades de pointes

Question 12

Rapid IV administration of what opioids can cause skeletal muscle rigidity?

Answer 12

• lipophilic drugs
• sufentanil, fentanyl, alfentanil, remifentanil
• described as chest wall rigidity or stiff chest syndrome
• best treatment is paralysis and intubation

Question 13

Naloxone antagonizes what opioid receptors?

Answer 13

• Mu (greatest affinity)
• Kappa
• Delta