Drugs For Pain Flashcards
Types of Anesthesia?
General
Local
Regional
Aspects of General Anesthesia?
LOC Analgesic Amnesia Muscle relax Inhibit reflex Non-toxic
Stages of anesthesia?
Analgesia
Delirium
Surgical Anesthesia
Cardio/respiratory collapse
What are the premedications>
Sedation Analgesia Antiemesis Infection Control Disease-modifying
Inhaled Anesthetic MOA?
Gas in neuronal membrane cause it to expand blocking ion channels
Organ effects of Inhaled Anesthetics?
Cardio: Reduce Contractility/tachycardia Pulm: dec RR CNS:dec metabolic rate inc blood flow Malignant hyperthermia Renal: decease GFR
Why dont u give inhaled anesthetic to recent head trauma?
Increase blood flow which increase ICP
IV anesthesia MOA
Bind to GABA chloride channels
Hypnosis and anesthesia w/o analgesia (give with opiod)
ADR of IV anesthesia?
Hangover bc lipid solubility. Bronchospasm/ reflex tachycardia
Given to inhbit movement especially in delicate surgical procedures
Neuromuscular blocker
Slow onset but provide basal level sedation
Gives you anterograde amnesia?
Benzodiazepines
Midazolam
Produces skeletal muscle movements, thrashing nausea
Etomidate
Bind to NMDA receptors inhibiting the excitatory effects of glutamate.
What does it produce?
Ketamine
Dissociative anesthesia
HTN
Tachycardia
Hallucinations
Lowers BP w./o myocardia depression. Used for same day surgery.
Propofol
What are considerrattions to take for patients going to rehab after surgery?
Confused
Woozy
Neuromuscular weakness.
Mucociliary response so want to cough and do breathing.
Neuronal cell death.
Highlights of local and regional anesthesia?
Regional at nerve to numb area
Local: topical
Quick recovery, remain conscious, dont mess with organs
Can take time to kick in.
MOA of local anesthetics?
Indication?
Block sodium channels: C fiberss then A delta, then motor.
For pain relief for local surgery
ADR of local anesthetics
Rarely
But sleepy/ light headed/ affect heart
What does Epi do with analgesia>?
Reduce systemic absorbtion and prolong duration of anaglesia
What are chemicals released with tissue injury?
K+ Serotonin Histamine Bradykinin Prostaglandins Leukotriens.
Pain transmission?
Via a delta and C fibers in lamina 1.
Release substance P and transmitted to ortex.
Opiods inhibit release of substance P at interneuron.
Substance that relieves pain acts on Mu receptor..
What can its action be reversed by?
Opiods
Naloxone.
Opiod and receptors?
Mu: get analgesia/ Bradycardia/ high abuse potential
Delta: lower abuse potential
Kappa: analgesia, sedation, dyspnea,dysphoria
All opiod recptors open _____ causing ______
Potassium Channels
Hyperpolarization and decrease nerve transmission. (Less substance P)
Cause euphoria which can lead to addiction.
Strong Agonist MOA effect?
MORPHINE
Bind to Mu and Kappa
Cause analgesia, sedation, euphoria.
Uses of strong agonist?
Acute pain, chronic cough, vasodilator
ADR of strong Agonist?
Sleepy Vomit Sweating Bradycardia Constipation Decreaases respiration (can die)
Chronic itchin
Frictopathia
Mild-mod agonists :
Bind to Mu and kappa but less than strong.
Block NE and seratonin
Codeine/tramadol
Routes of administration for opiods?
Slow release MS-Contin Patch IV Intrathecal Lollipop Fixed interval. Iontophoresis
First pass effect of morphine?
Large. So metabolized before it reaches systemic circulation.
Oral codeine and oxy preferred over morphine
or use morphine IV
Metabolyzing enzymes of opiods?
CY2D6 : take active drug and metabolize it to another drugs. May not respond well.
CYP3A4: produce non-active metabolites
Develops quickly and pt must continually administer higher does to get same effect
Tolerance
Pt feels withdrawal. What are signs?
What do you do?
Physical dependence.
Anxiety/irritable/hot flash/ basically fever
Give methadone cuz longer half life.
Tx for addiction?
Give methadone cuz blocks receptors and has longer half life.
Can cause arrhythmias
Which is easier?
Withdrawing from long-acting opiod vs short.
Long.
What does Buprnorphine do?
Treat addictions./withdrawal of long-acting opiods.
Bind to m receptor. Agonist at delta but antagonist at kappa.
Morphine antagonist?
What is something similar?
Displace opiod from receptor. To treat OD.
Naltrexone (longer halfife tho)
What is most effective way to treat addiction from chemical standpoint?
Combine Naloxone/Buprenorphine.
CALLED SUBOXON
For short-acting opiods.
Therapeutic concerns with opiods?
Drowsy/dizzy Schedule at peak action of opiod No heat over patch Prescribe lowest dose possible for no more than 3 days Use SOAPP (before opiods) COMM (on opiods)
