Opioids II/III Flashcards
Who is most likely to experience dysphoria from morphine?
-Females
-Pain-free individuals
Opiates act on the mu-receptors of ___, which is the reward center, and allows for the reinforcing effect
Nucleus Accumbens
Why do some patients taking opioids experience nausea?
Trigger chemoreceptor trigger zone
What does tolerance not develop to?
Constricted pupils
Constipation
Major toxic effect of opiods?
Respiratory depression (decreased sensitivity to medullary chemoreceptors)
In what condition can the respiratory depression caused by opioids be useful?
Pulmonary edema (“air hunger”)
-Alleviates patient’s conscious awareness of respiratory distress
Why do opioids have anti-tussive effects?
-Depress cough control center
What two ways can opioids cause endocrine disturbances in chronic users?
1) Decrease prolactin, corticosteroid, and gonadotropin levels
2) Menstrual disturbances (females) and impotence (males)
How do opiods affect smooth muscle?
-Increase tone of circular smooth muscle
-Less movement of propensive muscle
True or False:
Urine retention, increased biliary pressure, and decrease intestinal motility are effect of use of opioids?
True
True or False: opioids can interfere with cardiovascular system, causing postural hypotension and cutaneous vasodilation (both of which are due to histamine release)
True
Why is morphine less potent orally?
First pass effect
Can morphine cross the BBB?
Yes
What patients should be given opioids with caution?
-Immunocompromised (immunosuppresion)
-Asthmatics (bronchoconstriction - histamine release)
-Recent head injury (increase CSF)
-Seizure prone (lower seizure threshold)
Drug interactions with morphine?
1) CNS depressants (additive effect)
2) MAO inhibitors (coma/hyperpyrexia)
3) Speedball
Triad symptoms for opioid overdose?
1) pinpoint pupil
2) depressed rate of respiration
3) CNS depression
Treating opioid OD?
- Ventilation (admin O2-but may remove hypoxic drive)
- Narcotic antagonist (Narcan)
True or False: Opioids can be used to treat moderate to severe pain, as adjunct to anesthesia, as anti-tussives, or dyspnea of left heart failure
True
How does morphine compare to codeine?
Codeine is effective when administered orally (morphine is not)
Codeine is less potent - it is a weak opioid agonist
Morphine dosage?
30-60 mg PO
10 mg SC/IM
In most patients, codeine is metabolized to ___
morphine
Uses of morphine?
1) Anti-tussive
2_analgesic
People with CYP2D6 are more likely to overdose on _____
codeine
Why is meperidine not an appropriate treatment for chronic pain?
Build up of normepedrine can lead to seizures
When heroin enters the brain, what does it become?
Morphine + 2 acetyl groups
How does duration of action vary when methadone is used as analgesic vs. for opioid addiction?
-Analgesic: 4-6 hrs
-Opioid addiction: 12-24 hrs
____ can be used to treat breakthrough pain, supplement in surgical anesthesia, and transdermally for chronic pain
Fentanyl
How can opioid combination preparations cause liver damage?
-At high doses, may have toxic doses of acetaminophen, aspirin, or ibuprofen
What drug class has less abuse potential, compared to opioids?
Mixed agonist-antagonists
How does pentazocine act?
High doses: mu-antagonist
Normally:
-mu receptor (partial agonist)
-kappa receptor (agonist)
Although pentazocine is less effective for severe pain, it is also less likely to do what two thing? What is it more apt to caues?
1) respiratory depression
2) potential for dependence
more likely to cause CNS stimulation
Why does the Talwin NX include both pentazocine and naloxone?
Naloxone decreases chance of IV abuse (stops person from getting high)
Buprenorphine is a ___ agonist that acts at __ receptors
partial; mu
Main use of buprenorphine?
Reduce drug cravings in addicts
What two partial agonists have abuse deterrent formulations?
-Buprenorphine
-Talwin NX
What is the primary agent of office based treatment of opioid addiction?
Buprenorphine
___ is a weak agonist that inhibits synaptic re-uptake of NE and serotonin, can be used to treat mild to moderate pain
Tramadol
While Tapentadol is similar to Tramadol, how is it unalike? Alike?
Tapentadol has stronger mu activity and more effective than tramadol at treating pain (also more abuse potential)
-Both inhibit uptake of 5-HT and NE
Naltrexone is a long-acting ____ that treats primary ______
antagonist
etoh abuse
Two drawbacks of naltrexone?
1) Hepatotoxicity risk
2) Supppppper long acting (like 3-4 weeks long!)
What two drugs can be given to treat/prevent constipation from opioid use?
-Naloxegol (opioid antagonist - chronic; outpatient setting; less sytemic effects)
-Methylnaltrexone (for serious constipation resulting from higher doses)
True or False:
Features of acute withdraw include: dilation of pupils, HTN, tachy, goose flesh, yawning, sweating
True
Why does one feel bad when they withdraw?
Person becomes depleted of endorphins and enkephalins
Which is fatal: opioid or alcohol withdraw?
ETOH
Before beginning naltrexone, an opioid addict must first ___
be detoxified
Is Naloxone
