Opiods Flashcards
Mu endogenous ligands
B-endorphin
endomorphin
Enkephalin
Dynorphin A>B
Mu agonists
Morphine and other pure agonists
Mu1 effects
Supraspinal analgesia Sedation Hypothermia Euphoria Physical dependance
Mu2 effects
Spinal analgesia sedation respiratory depression GI transit decrease brady cardia
Delta endogenous Ligands
Met and leu enkephalin, B-endorphin
Delta agonists
Sufentanil (weak)
Delta Effects
analgesia
Antidepressant
Less: GI decrease/
Physical dependence/
respiratory depression than Mu
Kappa endogenous ligands
Dynorphin A&B
Kappa agonists
Butophanol > other partial agonists/antagonists
Kappa Effects
K1 - Spinal analgesia K3 - supraspinal analgesia Miosis physical dependence GI tract decrease Averse behavioral effects (psychotomimesis/dysphoria, sedation, diuresis)
Respiratory depression mechanisms
1) depress neurogenic drive in medula
2) Decrease response to CO2 increases (medulla chemoreceptors and aortic body chemoreceptors)
What are D isomers of opioids used for?
Cough suppression.
Lack respiratory depression, analgesia, tolerance, drowsiness
Opioid CNS ADRs
N/V via stimulation then blockade of chemoreceptor trigger zone
Opioid allergies
Very few people have a true allergy to opioids
Opioids and constipation
Inhibits peristaltic action but not mixing action. Churn that shit
Opioids and the gall bladder
Increased tone -> decreased secretion -> build up of pressure –> pain
Common request for opioids. Should it be accepted?
Low back pain.
Not idea, try NSAIDs, APAP, muscle relaxants
WHO 3 step ladder
1) Non-opioid +/- adjuvant
2) short acting opioid as required +/- non-opioid +/- adjuvant
3) sustained release/long acting opioid ATC + short acting as required +/- non opioid +/- adjuvant
Is it better to give schedule or prn? Why
Schedule, less likely to become dependent
Kappa agonist/mu antagonist drugs
Respiratory depression plateaus
Less smooth muscle contraction
Less dependence
However, less max efficacy
