Pharmacology Opiods and Anlgesics Flashcards
What are the three ways NSAIDS are involved with reducing/treating Pain
reduce activation threshold at peripheral terminals of primary afferent nociceptor neurons
decrease recruitment of leukocytes
crosses the blood brain barrier to prevent generation of prostaglandins that act as a pain producing neuromodulators in the spinla cord dorsal horn
what are the three endogenous opiods
endorphin, enkephalin, and dynorphin
endorphins use what receptor subtype mainly
mu
enkephalins use what receptor subtype maiinly
delta
dynorphin use what receptor subtype mianly
kappa
which two receptors can undergo desentiziation
mu and delta
is the decrease in apparent effectiveness if a drug with continuous or repeated administration
tolerance
is the state of adaptation manifested by receptor specific withdrawal syndrome produced by cessation of drug exposure
dependence
the CNS effects associated with opioids are mostly associated with what receptor
mu
what are the CNS effects of opioids
analgesia, euphoria, sedation, respiratory depression, cough suppresion, miosis, and nausea and vomitting
peripheral effects of opioids
constipation, bradycardia, and hypotension
how can tolerance be minimized
small amounts with longer dosing intervals (drugs with LONGER t1/2)
examples of strong opioid agonists
morphine, hydropmorphone, oxymorphone, methadone, meperidine, and fetanyl
examples of mild to moderate opioid agonists
codeine, hydrocodone, oxycodone and tramadol
examples of mixed agonist-antagonists
nalbuphine, butorphanol and buprenorphine
examples of pure opioid antagonists
nalozone and naltrexone
2D62X2 polymophism
increased conversion of codeine to morphine
2D6 polymorphism
decreased conversion of codeine to morphine
in what type of patients should you use caution for opioids
liver and kidney pts
what is the effect of the use of a pure agonist with a partial agonist
it may diminish analgesia and or induce a state of withdrawal
if you use opioids in patients with impaired pulmonary function it may…
lead to acute respiratory failure (due to the effect of respiratory failure)
if you use opioids during pregnancy….
may result in fetal physical dependence, shrill crying, irritability, diarrhea, and or seizures
use of opioids in patients with endocrine disease
prolonged and exaggerated response to opioids in patients with ardrenal insufficiency or hypothryoidism
what has a higher bioavailability than morphine
methadone
its isomers can block both NMDA and monoaminergic reuptake transporters
methadone
what is very effective for treating difficult to treat pain (neuropathic and cancer pain)
methadone
half live of methadone
long (25-52 hours)
what is widely used for treatment of opioid abuse
methadone
what is unique about methadone
prolonged QT syndrome
has signifncant antimuscarinic effects
meperidine
causes mydriasis and sometimes IV administration can cause increase heart rate
meperidine
what are the two severe reactions to meperidine
serotonin syndrome and acute narcotic overdose
serotonin syndrome
can block neuronal reuptake of 5HT, resulting in serotonergic overactivity
acute narcotic overdose
due to inhibition of hepatic CYP’s by MAO inhibitors
meperidine is metabolized to _________- and can cause increased CNS excitability and _________
normeperidine, seizures
most widely used in anesthesia applications
fetanyl
what is the most lipid soluble of the strong mu agonists ?
fetanyl
what has a high abuse potential among the strong mu agonists ?
fetanyl
which has a rapid termination among the strong mu agonists ?
fetanyl
examples of mild to moderate mu agonists ?
codeine, hydrocodone, and oxycodone
codeine metabolism is variable and is not recommended for
cancer pain management
is synthetic codeine
tramadol
what is the mechanism of action of tramadol ?
based on MOR activity and NE and 5HT reuptake blockade
what are the contraindications of tramadol ?
pts. taking MAO inhibitors and SSRI’s
what drugs are not easily reversible with mu receptor antagonists ?
mixed agonist antagonists
causes psychotomimetic side effects (dysphoria, racing thoughts, and distortions of body image)
butorphanol
analgesia through KOR is more effective in
women
has a long duration of action and is effective in treating for opioid abuse
buprenophrine (high dose results in mu receptor antagonist action)
naloxone
short duration of action, administered parenterally but the pt. must be monitored until it is certain that the offending opioid is NO longer in the system
naltrexone
patient must be monitored until ALL opoids have been eliminated, long half life (10 Hours), administered orally in outpatient settings and is used in maintainence programs)
amitriptyline and nortryptline do what
block sodium channels and decrease NE and 5HT reuptake
duloxetine and venlafaxine
inhibit 5HT and NE reuptake
gabapentin and pregabalin
inhibit voltage gated calcium channels (calcium channel ligands GABA analogs)
blocks sodium channels and prevents generation of action potential responsible for nerve conduction (pain)
lidocaine
what is the first line treatment for trigeminal neuralgia
carbamazepine
carbamazepine is associated with risk for what
aplastic anemia
used for chronic pain and postoperative pain and is a NMDA receptor antagonist
dextromethorphan and ketamine
dextromethorphan and ketamine produce
psychomimetic side effects
clonidine
acts on alpha 2 receptors in the DRG of spinal cord to produce anti-nociceptive state
clonidine is associated with what which limits its usefulness in pain management
postural hypotension
