Opioids Flashcards
What effects does the mu receptor exert
Analgesia
Euphoria
Constipation
Respiratory depression
Dependence
What effects does the kappa receprot exert?
Analgesia
Diuresis
Dysphoria
What effects does the delta receptor exert?
analgesia
anxiolysis
Explain the neuroscience behind opioid dependence
Dopaminergic cells within ventral tegmental area produce dopamine, which is released into the nucleus accumbens upon stimulation of µ receptors, producing the euphoria and reward that helps drive repeated use. With repeat opioid exposure, µ receptors in the ventral tegmental area neurons become less responsive to opioid binding and less dopamine is released. This causes causes dysphoria and depressed mood and contributes to drug craving.
Explain the mechanism of methadone
Full agonist targeting mu receptors
Explain the mechanism of buprenorphine
Partial agonist targeting µ receptors (also a partial k agonist or functional antagonist (possibly with antidepressant effects), and a weak δ antagonist.
Explain the mechanism behind naloxone
Antagonist targeting all opioid receptora
Explain the mechanism of naltrexone
Reversible competitive antagonist at mu and Ä receptors
What is the half life of methadone
15-22 hours
What is the half life of buprenorphine (oral)
24-42 hours
What is the half life of naloxone
30-120 minutes
What is the half life of naltrexone
4-6 hours
What complication is naloxone associated with ?
non-cardiogenic pulmonary oedema
Which non opioid drugs can help with opioid withdrawal?
Clonidine
Lofexidine
