Opioids I Flashcards
Opium
Dried latex from the opium poppy
Untransformed
Opiates
Any drug derived from opium
(Morphine and Heroin)
Opioid
Any drug that binds to an opioid receptor (Includes opiates and synthetic opioid agonists)
(Fentanyl and Heroin)
Narcotic
Used to refer to drugs with sleep inducing properties
Now is referred to illegal use of opioids with non-medical purposes
What are the 4 opioid receptors
Mu
Delta
Kappa
Orphanin receptor ligand (ORL-1) or NOP
What differs between the different opioid receptor types
Receptor distribution
Ligand specificity
Where are Mu Opioid Receptors? What are they responsible for?
Subcortical cortex, thin vertical line near centre
Emotional reactions
Where are Kappa Opioid Receptors? What are they responsible for?
Cortex region, outlines the edges of the cortex
Coordination and sensory info
Where are Delta Opioid Receptors? What are they responsible for?
Cortex region, horizontal lines spanning both cortical and subcortical cortex
Coordination and sensory info
Where are ORL-1 Opioid Receptors? What are they responsible for?
Wildly expressed in the central nervous system, basically everywhere in the brain
May be involved in fear processing
Describe homology between opioid receptors
The centres of opioid receptors are highly conserved and are identical regions between all opioid receptors
The ends of the opioid receptors differ between the different types, this difference dictates what ligand specificity and what ligand binds for different opioid receptors
What is the most common opioid receptor
Mu opioid receptors
What are the effects of a Mu agonist, give some examples
Analgesia
Reward
Cough suppressant
Respiratory depression
Constipation
Morphine, heroine, codeine
What are the effects of a Mu antagonist, give some examples
Aversive
Prevents reward
Blocks overdose
Naloxone
What are the effects of a Delta agonist
Not rewarding
No analgesia effects
Seizure inducing
What can delta agonists potentially treat, what are the side effects
Could potentially treat chronic migraines, leads to unregulated cortical activity, causes seizures
What are the effects of a Kappa agonist, give some examples
Aversive
Hallucinogenic
Anxiogenic (Causes anxiety)
What are the effects of a Kappa antagonist
Potential antidepressant and reverses anxiety (anxiolytic)
What are the best analgesics
Opioids are great at blocking acute pain
List a partial agonist at the mu opioid receptor, what are its benefits
Buprenorphine, mild to moderate analgesic efficacy, has a safer therapeutic index
Only partially inhibits breathing complex, impossible to overdose