Ch 24 Flashcards
drugs that relieve pain without causing loss of consciousness
Analgesics
the most effective pain relievers available
Opioid analgesics
medications in the opioid analgesics family
morphine
fentanyl
codeine
oxycodone (OxyContin)
any drug, natural or synthetic that has actions similar to those of morphine
opioid
a more specific term that applies only to compounds present in opium
opiate
What are the 3 families of peptides that have opioid -like properties
enkephalins
endorphins
dynorphins
what 3 categories do the opioid analgesics fall into?
1) pure opioid agonists
2) Agonist-antagonist opioids
3) pure opioid antagonists
what effects do pure opioid agonists produce?
analgesia euphoria sedation resp depression physical dependence constipation
prototype of the strong opioid agonists
Morphine
Prototype of the moderate to strong agonists
Codeine
List the 4 agonist-antagonist opioids available
Pentazocine
nalbuphine
butorphanol
buprenorphine
When administered alone, the agonist-antagonist opioids produce
analgesia
when an agonist-antagonist opioid is given with a pure opioid agonist, these drugs can
antagonize analgesia caused by the pure agonist
what drug is considered the prototype for the agonist-antagonist opioid group
Pentazocine
which drug class in the opioid analgesic grouping is manly used for reversal of resp and CNS depression caused by overdose with opioid agonists?
pure opioid antagonists
what is the prototype drug for pure opioid antagonists
Naloxone (Narcan)
what pure opioid antagonist is used to treat opioid induced constipation
methylnaltrexone
pharm effects of morphine
analgesia sedation euphoria resp depression cough suppression suppression of bowel motility
side effects of morphine
urinary retention emesis orthostatic hypotension miosis biliary colic
The time course for resp depression after PO morphine begins up to ___ minutes after ingestion
90
what populations are most sensitive to resp depression with morphine
very young
older adults
those with resp disease
what should be avoided while taking morphine to prevent further resp supression
alcohol
barbiturates
benzodiazepines
potential complications of constipation secondary to opioid use is
fecal impaction
bowel perforation
rectal tearing
hemorrhoids
Goal for management of constipation secondary to opioid use
produce a soft, formed stool every 1-2 days
Principal nondrug measures to combat constipation secondary to opioid use
physical activity
increased intake of fiber and fluids
prophylactic treatment for constipation secondary to opioid use
a stimulant laxative such as senna to counteract reduced bowel motility plus Miralax (osmotic laxative)
rescue therapy for constipation secondary to opioid use
strong osmotic laxative such as lactulose or sodium phosphate
last resort for constipation secondary to opioid use
methylnaltrexone (Relistor)
Can methylnaltrexone (Relistor) cross the blood brain barrier?
no and hence does not reverse opioid induced analgesia
classic triad of signs for opioid overdose
coma
resp depression
pinpoint pupils
what are the 4 different routes that fentanyl can be given?
parenteral
transdermal
transmucosal
intranasal
what schedule med is fentanyl
II
Fentanyl is metabolized by
CYP3A4 (isoenzyme of cytochrome P450)
where should a fentanyl patch be applied
skin of the upper torso
what is the time line for fentanyl patch
reaches effective levels in 24 hours
levels remain steady for another 48 hours
age weight min for transdermal Fentanyl
should not be used in children younger than 2 years or children younger than 18 who weigh less than 110 lbs
fentanyl overdose risk for transdermal patch
If resp depression develops, it may persist for hours after patch removal, due to continued absorption of fentanyl from the skin
Transmucosal fentanyl rules
approved only for breakthrough cancer pain in patients at least 18 years old who are already taking opioids around the clock and have developed some degree of tolerance, defined as needing, for 1 week or longer, at least: 60mg of oral morphine a day, or 30 mg of oral oxycodone a day or 25mg of oral oxymorphine a day or 8mg of oral hydromorphone a day or 25mcg of fentanyl per hour or an equianalgesic dose of another opioid .
if a patient switches from one transmucosal product to another…..
dosage of the new product must be titrated to determine a strength that is safe and effective
what is Methodone (Diskets, Dolophine, Methadose) used for
pain and to treat opioid addiction
what test should be run before a pt is placed on Methodone (Diskets, Dolophine, Methadose)
This drug can cause QT prolongation
Pt should receive an ECG before treatment, 30 days later and annually thereafter. If the QT interval exceeds 500ms, stopping or reducing the methodone should be considered
Black box warning Methodone (Diskets, Dolophine, Methadose)
QT prolongation
Torsades de pointes
If pt has existing QT prolongation or a family history of long QT syndrome and in those taking other QT prolonging drugs consider not using
resp depression that can be fatal
what schedule drugs are Hydromorphone, Oxymorphone, Levorphanol
II
what is the difference between a moderate to strong opioid agonist and morphine which is a strong opioid agonist?
both produce analgesia, sedation and euphoria
the both can also cause resp depression, constipation, urinary retention, cough suppression and miosis.
The differences are quantitative: the moderate to strong opioids produce less analgesia and resp depression than morphine and have a somewhat lower potential for abuse
codeine alone is classified under what schedule?
II
Codeine combo such as norco is under what schedule
III
codeine used in cough syrups is what schedule
V
Blackbox for codeine
In the liver about 10% of each dose of codeine undergoes conversion to morphine. The enzyme responsible is CYP2D6 (The 2D6 isoenzyme of cytochrome P450) Among ultrarapid metabolizers, which carry multiple copies of the CYP2D6 gene, codeine is unusually effective and has led to death in some children. Severe toxicity can also develop in breastfed infants whose mothers are taking codeine. The cause is high levels of morphine in breast milk, due to ultrarapid codeine metabolism.
Oxycodone (oxycontin, Roxicodone) and Hydrocodone has analgesic actions equivalent to those of
codeine and is a schedule II
Codeine
Oxycodone
Hydrocodone
Tapentadol
fall into what class?
Moderate to strong opioid agonists
which moderate to strong opioid agonists causes less constipation than traditional opioids
Tapentadol (Nucynta)
pain medications in the Agonist-Antagonist Opioid Category
Pentazocine (Talwin)
Buprenorphine (Butrans)
what Agonist-antagonist opioid can be pre-treated with Narcan to prevent toxicity. However it cannot readily reverse toxicity bc it binds very tightly to its receptors and hence cannot readily be displaced by narcan
Buprenorphine (Butrans)
What is Buprenorphine approved for
analgesia and opioid addiction
Cardiac precautions for Buprenorphine
prolongs QT interval
should not be used by patients with long QT syndrome or a fam history of long QT or by patients using QT prolonging drugs
Risk for adverse effects of Buprenorphine may be increased by
psychosis
alcoholism
adrenal corticoid insufficiency
severe liver or renal impairment
opioid agonist with less constipation than traditional opioids
Tapentadol
