Opioids Flashcards
stimulatory effects of opioids
miosis
convulsions
constipation
vomiting
brain mu
mu 1
peripheral mu
mu 2
endorphin
mu
enkephalin
delta
dynorphin
kappa
analgesia: increase pain tolerance and decrease perception and rxn to pain
sedation
respiratory depression: decrease response to increase pCO2, increase intracranial pressure
(do not give O2, give naloxone)
Gi coupling side effects of opioids
cardiovascular - vasodilation ( avoid in head injury)
urinary retention, urgency to void
biliary: sphincter constriction causing biliary colic
renal fxn (gfr) is decrease by opioids due to decrease renal blood flow
can cause gynecomastia or SIADH (stim release of ADH, PRL, somatotropin)
increase histamine release - pruritus
cough suppression - codeine
other SE of opioids
CI: head injury, pulmonary dysfxn, pregnancy, hepatic/renal dysfxn, adrenal/thyroid def
opioids
mu agonist
glucuronidation
motphine 6 glucuronide is highly active, caution in renal dysfxn
morphine
MOA: ionic channel, through release of endogenous opioid peptides, modulate pain through ascending/descending nerves
opioids
Classic triad: OD toxicity
pinpoint pupils
respiratory depression
coma
tx for OD toxicity
IV naloxone
occurs to all effects, except mitosis and constipation
tolerance of opioids
physical and psychological - addiction
dependence of opioids
Mech of tolerance
1) increase cAMP
2) receptor recycling blockage
3) receptor and G protein coupling
uses for opioids
analgesia Anesthesia manage acute pulmonary edema cough suppression antidiarrheal
opioids used in anesthesia
fentanyl
morphine
can cause chest muscle tone increase, chest rigidity
opioids in used in cough suppression
codeine
dextromethorphan
opioids used as antidiarrheal
loperamide
diphenoxylate
metabolized by liver p450 CYP2D6 (demethylation) to morphine
codeine
proopiomelanocortin (POMC)
precursor for endorphins and enkephalins
yawning, anxiety, sweating, goose bumps, lacrimation, rhinorrhea, salivation, spasms, muscle cramps, CNS originating pain
withdrawal - abstinence syndrome of opioids
tx for withdrawal
methadone
buprenorphine
clonidine
long acting t half 25-52 hrs
Maintenance programs for addicts
permits slow tapering effect and diminishes intensity of abstinence syndrome
methadone
maintenance program
t half 24-60 hrs
low efficacy at mu receptor with high affinity
buprenorphine
A2 agonist
cancel over activity of sympathetic nerve system
clonidine
opioid antagonists
naloxone
Naltrexone
methylnaltrexone
IV reversal for respiratory depression
naloxone
PO, decrease craving for alcohol and used in opiate addiction
naltrexone
tx for post op ileus, opioid induced constipation (doesn’t cross BBB) and won’t precipitate withdrawal
methylnaltrexone
tx for baby with opioid withdrawal sx
1) diazepam
2) camphorated tincture of opium - oral
3) methadone - oral
opioids that interact with SSRI or MAOI causing serotonin syndrome
meperidine
dextromethorphan
tramadol
stong agonists
morphine methadone meperidine fentanyl heroin
moderate agonists
codeine
oxycodone
mixed agonists/antagonists
buprenorphine
butorphanol
pentazocine
nalbuphine
agonist and reuptake inhibitors
tapentadol
tramadol
used in moderate pain and RA
tapentadol
tramadol
