Central analgesics: Opioids Flashcards
3 receptors for opioids
Mu: binds B endorphins
Kappa: Binds dynorphins
Delta: Binds Enkephalins
Stimulation of opioid receptors
Decreases neurotransmitter release by decreasing Ca entry and increasing K exit
Most abundant receptor for opioids
Mu
Cardinal sign of opioid use
Pinpoint pupils due to blockade of NE release
CNS effects of opioids
Analgesia (decreased affective aspect of pain), euphoria, Sedation, respiratory depression, cough suppression, N/V due to activation of chemo trigger zone, pinpoint pupils
Peripheral effects of opioids
Constipation, possible vasodilation
Meperidine
Opioid agonist
Strong antimuscarinic
Tachycardia, no pupil constriction, no GI/GU spasm
Methadone
Opioid agonist
Used for maintenance of opiate addicts and analgesia
Additive respiratory depression with heroin
Long half life
“-one”
Opioid agonists
Hydrocodone, oxycodone, etc.
Intermediate potency
“-nil”
Opioid agonist
Alfentanil, Fentanyl, etc.
Highest potency
Codeine, Tramadol, Tapentadol
Lower potency opioid agonist
Buprenorphine
Slow dissociation from mu receptors
Effective in detox or maintenance in opiate addicts
Less respiratory depression than methadone
Naloxone
IV to reverse opioid overdose
Naltroxone
Opioid antagonist
PO, long acting, used in alcohol and opiate dependencies to decrease craving
Methylnaltrexone
Opioid antagonist
Treats opioid induced constipation
