Pharm 10 Opioids Flashcards
Main analgesic receptor
Mu Opioid Receptor (G-protein)
Opioid Receptor MOA
- Decrease Ca current (decrease NT release)
2. Increase K current (Hyperpolarize)
Nociceptive afferent synapse
Dorsal Horn
Descending pathway synapse
Modulate dorsal horn via interneuron
Main Opioid effect
Block Glutamate and Substance P release at Dorsal Horn synapse
Opioid effect on Rostral Ventral Medulla
Block inhibition, let RVM inhibit Dorsal Horn
Opioid effect on interneuron
Hyperpolarize, block excitatory drive to Dorsal Horn
Only Opioid effect not mediated by Mu receptor
Psychotomimesis
Morphine problem
Poor lipid solubility
-Morphine-
MOA
MOR
-Morphine-
Metabolism
Major SE
CYP450
Respiratory depression
-Morphine-
CI
MAOI
Alcohol
-Fentanyl-
Indication
MOA
Severe pain
Very potent MOR (100x morphine)
Very lipophilic
-Fentanyl-
Useful application
Transdermal patches
-Fentanyl-
SE
Less nausea
More muscle rigidity
-Methadone-
Indication
MOA
Analgesia and Heroin withdrawal
Potent MOR agonist
-Meperidine-
MOR agonist
Less potent and quicker than morphine
-Meperidine-
Unusual effects
Doesn’t prolong labor
Not antitussive
Less constipation
-Meperidine-
SE
Toxic metabolites
Tachycardia
Dysphoria
-Codeine-
Indication
MOA
Moderate pain
Cough suppressant
MOR, unless you have CYP2D6 mutation (10%)
-Codeine-
Metabolism
CYP450
Need to metabolize to morphine with CYP2D6
-Propoxyphene-
Toxic Psychosis
Heart Toxicity
-Oxycodone-
Indication
MOA
Moderate pain
+acetaminophen = percocet
MOR
-Hydrocodone-
Moderate pain
+acetaminophen = vicodin