Opioids Flashcards
Which parts of the brain are most involved in presence of acute pain?
Anterior cingulate, Insula, Basal Ganglia, Thalamu
Whicih part of the brain plays a role in the anticipation and perception of pain?
brainstem
Which are of the brain increases in activation with chronic pain?
Prefrontal Cortex
How does the sensation of pain travel?
Nociceptors -> action potential -> dorsal horns in spine ->spinothalamic tract-> thalamus and higher centers of brain
What are hte 2 types of pain?
Acute pain
Chronic Pain
How do opioids work?
Bind to opioid receptors
What are the receptor types for opioid receptors?
Delta (d1,d2): OP1
Kappa : OP2
Mu :OP3
Nociceptin: OP4
How do opioids relieve pain?
Induce analgesia by reducing the amount of inflammation -> reduce elaboration of pain -> reduce sensation of pain
How do opiods reduce pain transmission at the presynaptic level?
Activate presynaptic opioid receptors -> dec cAMP -> dec Ca2+ influx-> inhibit release of excitatory NT
How do opioids reduce pain transmission at the postsynpatic level?
Binding -> hyperpolarizaiton of membrane ->dec chance of action potential
What are the CNS effects of opioids
Euphoria SEdation Cough Suppression Miosis Temperature Changes: via k receptor REspiratory Depression: MOST IMPORTANT
What are the strong opioids?
Morphine
Methadone
Meperidine
What are hte moderately strong opioids?
Codeine
Oxycodone
What are the antagonists to opioids
Naloxone
What is the prototypical opioid?
Morphine
What are the side effects of morphine?
Constipation, Addiction, Tolerance,
What is Meperidine used for?
Analgesic to relieve moderate/severe pain
Biliary Spasm
Renal Colic
What are the side effects to Meperidine?
Serotonin Syndrome
Seizure
Dysphoria
Tremor
*Cannot be countered with NAloxone
What is hydrocodone?
Opioid similar ot morphine that targets mu and delta receptors
Moderately strong
What is hydrocodone used for?
Treat moderate to severe pain
Anti-tussive: suppress coughing
What are the side effects of hydrocodone?
GI problems, anxiety, miosis, REspiratory problems
What are the toxicities of hydrocodone?
LOC, Muscular seizure, sleeping problems
What is the mechanism for euphoria?
Morphine binds mu receptor -> inhibit GABA secretion -> no GABA inhibition -> large release of dopamine -> euphoria due to inhibition of inhibitor of dopamine
What is codeine
Moderately strong opioid used for mild/moderate pain as well as cough, diarrhea, IBS, narcolepsy
What are the side effects of codeine?
Euphoria, itching, urinary retention, depression, constipation
What is pentazocine
Agonist/Antagonist analgesic for mild/moderae pain, especially dental extraction
What are hte side effects of pentazocine?
WEak antagonization of analgesic effects of morphine/meperidine
Hallucinations
What is naloxone
opiate antagonist that is used to prevent/reverse effects of opioids, especiialy respiratory depression, sedation, and hypotension
How does naloxone affect a normal person?
No effect
What are hte signs of opioid overdose?
Blue lips, unresponsive to pain stimuli
What happens in opioid overdose?
BP drops due to increased blood vessel size
Lungs suppresssed and slows down
Stomach has decreased GI activity
SExual organs messed up
What is methadone?
Strong opioid analgesic
Agonist of mu and delta receptors and glutamate and Ach receptors
What is methadone used for?
Treatment of opiate drug dependence as it binds to receptors and prevents binding of other opioids -> decrease desire for further opioid intake -> decreases craving but may be dependent on methadone
