3 - Opioids Flashcards
What are Mu1 receptors responsible for:
Analgesia
What are Mu2 receptors responsible for:
Respiratory depression, miosis, reduced gastric motility, sedation, euphoria, pruritis, urinary retention, PHYSICAL DEPENDENCE
What are Kappa receptors responsible for?
Contribute to analgesic properties (but Mu1 is responsible for most of the analgesia)
What is the Delta receptor responsible for?
Located in the periphery and selective for enkephalins
Which is more hydrophilic - morphine or fentanyl?
Morphine
Which is more lipophilic - morphine or fentanyl?
Fentanyl
What causes tolerance?
Down-regulation of opioid receptors
What is opioid-induced hyperalgia?
Increased pain or pain sensitivity without a change in medical condition
Desensitization is the result of:
Down-regulation
Which opioid is associated with the greatest histamine release and thus “itching” sensation?
Morphine
Morphine - MOA?
High affinity for Mu1 and Mu2
Weak affinity for Delta/Kappa
Morphine - pharmacokinetics:
Significant first pass effect if oral
Least lipophilic - only a small amount crosses BBB -> less euphoria than fentanyl or heroin
Will cross placenta
Heroin is __ times more potent than morphine
6
Presence of morphine in urine could indicate exposure to:
Morphine
Heroin
Codeine
Morphine - AE’s?
Increases ICP (caution in head injury)
Respiratory depression
N/V
Pruritus
HOTN
Hydromorphone (Dilaudid) - MOA:
Mu receptor agonist
Metabolite of morphine
More lipophilic than morphine
Hydromorphone (Dilaudid) - note on extended release form:
Requires provider training q 2 yrs - Risk Evaluation and Mitigation Strategy (REMS) drug
Hydrocodone ER (Zohydro ER) - MOA:
Less binding affinity than morphine
Metabolizes to hydromorphone
Oxycodone (OxyContin) - MOA:
Mu receptor agonist - low binding affinity
Metabolizes to noroxycodone and oxymorphone (active metabolites)
Oxymorphone (Numorphan) - MOA:
Semi-synthetic Mu receptor agonist
Greater analgesic profile than morphine
Codeine - MOA:
PRODRUG (no analgesic activity)
Metabolized to morphine
Codeine - clinical use:
Mild to moderate pain
Antitussive
Codeine - box warning:
Death delated to ultra-rapid metabolism of codeine to morphine
Not recommended for peds <12
What is the CYP enzyme responsible for converting codeine to morphine?
CYP2D6
If Codeine is single ingredient, what schedule?
II
If codeine combined with another analgesic (i.e. APAP), what schedule?
III