3. Opiods Flashcards
What are the 3 types of endogenous opiods?
- endorphins
- enkephalins
- dynorphins
Where are endorphins produced?
in the pituitary and hypothalamus
What type of drugs imitate endophins?
opiods
How do opiods affect the pain signal?
- can excite inhibitory neurons
- can inhibit the pain stimulus coming up the spinal cord
What is the mechanism of action of opiods?
They cause hyperpolarization of nerves by opening K+/Ca2+ channels
What is the most important opiate receeptor when it comes to pain?
Mu
What would happen if a person had no mu receptors?
Opiates would not work and they would feel higher levels of pain.
Morphine, codeine, hydrocodone, oxycodone and hydromorphone are all ____________ derivatives.
Phenanthrene
Merperidine, fentanyl and sufentanil are all ___________ derivatives.
Phenylpiperidine
Methadone is a ____________ derivative
Diphenylheptane
What is diacetyl morphine also known as?
heroin diamorphine
Where can you find a natural source of opiates?
in the opium poppy
papaver somniferum
Why is diacetyl morphine so addictive?
Because it is 10x more lipid soluble than morphine (gets into the brain quicker)
What are 7 pharmacological effects?
- inhibition of pain and pain perception
- sedation and anxiolysis
- depression of respiration
- cough suppression
- reduction of intestinal motility (useful for diarrhea)
- pupillary constriction
- nausea and vomiting
What should you look for in a pt if you suspect opiate overdose?
- respiratory paralysis
- reduced judgement
- reduced cognitive ability
- pupil constriction***
What is clinically useful about respiration reduction caused by opiates?
If a pt has a lung disorder, opiates can reduce their resp. rate to bring them more comfort.
Only used in pts that are going to die soon.
What are the 4 opiod uses?
- pain
- diarrhea
- coughing
- “panic” breathing (COPD)
What are the 3 dosing methods for pain?
- by the mouth
- by the clock
- by the ladder
If you have a pain level of 0-3, what type of pain is this and what therapy should be given?
mild pain
acetaminophen
If you have a pain level of 4-6, what type of pain is this and what therapy should be given?
Moderate pain
Codeine
If you have a pain level of 7-10, what type of pain is this and what therapy should be given?
Severe pain
Morphine
Although oral dosing is LESS effective than IV, what are 3 benefits of oral dosing?
- Longer term effect –> less frequent doses
- Avoids the “highs” –> less addictive
- Safer in terms of overdose
What does “by the clock” dosing imply?
Why is this a good dosing plan?
That you will be dosing the pt based on time and not by the pain they feel.
Good therapy because when you take doses based on pain, you will eventually need a higher and higher dose.
What are 3 benefits of “by the clock” dosing?
- Uses less drug. (takes more drug to bring pain down than maintaining a pain-free state)
- avoids the euphoria with release of pain –> less addictive
- avoids development of chronic pain syndromes
