Opioid Analgesics II Flashcards
Fentanyl onset time
7-15 minutes
Hydromorphone Dosing Interval
4-6 hours
Why to change your opioid?
Ineffective even at correct levels
Tolerance
Side effects
$$$
Review calculations using the table on slide #36
He says he will put one on the test
Drugs used to help patients with opioid induced constipation (and how they help).
Senna (Triggers fluid secretion and colonic contraction)
Polyethylene glycol (Stool Softener)
Dioctyl sodium sulfosuccinate (Stool softener)
Peripherally restricted mu antagonists
Name three peripherally restricted mu opioid antagonists
Methylnaltrexone
Alvimopan
Naloxegol
Why do opioids trigger pruritis
Heteromer w/ Gastrin releaseing peptide recetpor activates the release of Histamine from Mast cells.
Coadminister an anti-histamine
Which opioid side effects are associated with patients with little/no tolerance
Constipation
Itch
Miosis
Explain the difference between tolerence and hyperalgesia
Tolerance – increased dose to produce equivalent effect
Hyperalgesia – changes in opoid efficacy lead to incresed in pain intensity to a stimulus
How does opioid tolerance happen molecularly?
Activation of MORs by morphine causes a persisitant inhibition of Adenylyl CYclase, causing the cell to upregular AC. This increases cAMP and causes cellular tolerance to opoid effects
How does tolerance lead to hyperalgesia
When opioids are removed, a cell now produced more cAMP than it efer would normally. Elevated AC also promotes expression of more receptors for pain transmission.
Signs of opioid induced hyperalgesia
Pain not releived by opioid
Diffuse pain
Cold pressor test
What to do for opioid induced hyperalgesia patients
Switch between phenanthrenes and non-phenanthrenes
Use an NMDA antagonist (Methadone)
opioid detox – switch to clonidine/diazepam
Important opioid drug-drug interactions
Depressants (all lower resp. rate) Antipsychotics TCAs Antihistamines Meperidine (inhibit MAOs, SSRIs --> Serotinin Syndrome)
Symptoms of acute overdose of morphine/heroin
Coma Depressed Respiration Pinpoint Pupils Needle Marks Mixed Poisonings common w/ barbiturates and ethanol
Treatment for opioid overdose?
Supportive – Maintain Resp. and CV fxn
Naloxone (Narcan)
When in a withdrawl process will buprenorphine help?
More than 24 hours in
Less than 24 hours, it will trigger the withdrawl symptoms
opioids used to treat opioid abuse
Methadone
Buprenorphine
Suboxone, Zubsolv
Buprenorphine is mixed with _____ to prevent it from being IV administered. What does _____ do?
Naloxone
Its an opioid antagonist
opioids that help treat alcohol abuse disorder
Naltrexone and Nalmefene (used off label in US)
