Pharm Pain Flashcards
Noxious stimulus (chemical, thermal, mechanical) of nociceptors releases neural chemicals that stimulate other nociceptors. Transmita signal to spinal cord. What are types of neural chemicals?
Bradykinn, histamine, prostaglandins, leukotrienes, serotonin, substance p, potassium
Transmission
Action potential moves from site of stimulus to the dorsal horn of the spinal cord, then to CNS
A delta
Large diameter/sparsely myelinated
Sharp localized pai
C fibers
Small diameter: unmyelinated:
Dull aching pain
From dorsal horn, _______ are released
Neurotransmitters
Glutamate, substance p, calcitonin related peptide
Stimulators and excitatory transmitters send pain to signal CNS
Perception, pain impulse is relayed through _______ to ______
Thalamus, higher cortical structures
Modulation
Inhibition of impulse via brainstorm by release of endogenous opioids, serotonin, NE, GABA
Help temp escape pain
An estimated _____ of patients presenting to doc offices with no cancer painsymptoms receive an opioid
20% or 1 in 5
Addiction
When using for beyond what it is meant for to the point it is negatively impacting daily lives
Abuse
Using med beyond it’s intended therapeutic use for eurphoric effects
Tolerance
Using same dose and not getting same effect. Require increased dose to accomplish same effect
Dependence
Need medication to go about regular activities of daily living
More than how many days increase risk for addiction of opiates?
5
Many states limit first time prescriptions to 3, 5, 7 days
What meds can be just as effective for post op pain
NSAIDs
Percentage of pts s/p elective surgery continue to use opiates for at least 90 days
6% suggest not all opiates are cont for surgical pain
44% of opiate deaths age group
Greatly increased 45-64 and addiction treatment >50 increased dramatically
Opiate use ffor
General surgery
Women’s health
Musculoskeletal
4-9 days
4-13 days
6-15 days
No more than 2 weeks for all
What is esmolol broken down by
Red cell esterases, responsible for short half-life and duration
Pinpoint pupils
Miosina, kappa receptor
All opioids despite diverse structures share a ________ moiety which seems to provide analgesics activity
N-methylpiperdine
Opioids must have what to form a strong bond at the opioid receptor?
Ionized
What is an opioid prodrug?
Codeine, metabolized to work CYP2D6 to morphine. Only about 10% of codeine is converted
Tylenol vs t3 codeine tylenol
Has same outcome in clinical trial
Why is morphine not a patch?
Not lipophilic enough to absorb through skin
When is morphine most effective?
When given before acute surgical stimulus.
Visceral, skeletal, and integumentary pain
Inside CNS M6g is how many more times potent than morphine?
100x. Enters CNS by mass action in chronic use or renal fail
Why does morphine increase ICP
Decrease in spontaneous ventilation, buildup of CO2. Most significant increase in ICP compared to other opioids
What centers cause Resp effects related to CO2 and periodic breathings
brainstem, pontine, and medullary
What does morphine stimulate to cause N/V.
CTZ-Chemoreceptor Trigger Zone in medulla oblongata
What therapy should you not use to prevent opioid induced constipation?
Docusate monotherapy
What receptor causes respiratory depression?
Mu2
Med for Beta blocker overdose and how does it work?
Glucagon, boosts cyclic amp to bring HR up.
What binds to mu gut receptors and does not interrupt mu pain binding to prevent conspitation
mu antagonist
What muscle tone is increased to gives sense of having to urinate?
Detrusor
What makes difficult to urinate with opioids?
increase vesicle sphincter tone
Morphine can cause what to make it difficult to mask or intubate patient?
thoracic and abdominal muscle rigidity
Which opioids react most with MAO and symptoms caused?
Morphine and demerol. CNS depression and hyperpyrexia
Dilaudid active metabolites and histamine?
No active metabolites and less histamine
Effect site equilibrium fentanyl
approx. 6minutes
Can fentanyl cause bradycardia?
Yes, secondary decrease BP and CO
Synergism triad with opioids leading to hypnosis and ventilation depression?
opioids, benzos, and muscle relaxants
FDA recommendation for dosing opioids and benzos together?
2 hours apart
Name of fentanly lollipops? for cancer and preop
Actiq
Sufentanil benefit over fentanyl?
None really, used when fentanyl shortage. Only difference 5-10x more potent and slightly shorter half life
Sufentanil CNS effect different
Decreased CMRO2 and CBF
Alfentanil effect site equilibrium time
1.4minutes or 1/3 of fentanyl
Remifentanil elimination time?
less than 6 minutes due to ester linkage metabolized by nonspecific plasma and tissue ESTERASES to inactive metabolite
