Analgesic Drugs Flashcards
Name the opioids
morphine, fentanyl, codeine, loperamide, methadone, meperidine, dextromethrophan, diphenoxylate, pentazocine
Mechanism of opioids
act as agonists at opioid receptors to modulate synaptic transmission
- opens K+ channels, closes Ca2+ channels –> decreased synaptic transmission
inhibits release of Ach, NE, 5-HT, glutamate, substance P
Name the opioid receptors
mu = morphine lambda = enkephalin kappa = dynorphin
Use of opioids
pain, cough suppression (dextromethorphan), diarrhea (loperamide, diphenoxylate), acute pulmonary edema, maintenance programs for heroin addicts (methadone, buprenorphine + naloxone)
Name the opioid used for cough suppression
dextremethorphan
Name the opioids used for diarrhea
loperamide
diphenoxylate
Name the opioids used for heroin addicts
methadone
buprenorphine + naloxone
Toxicity of opioids
addiction, respiratory depression, constipation, miosis (pinpoint pupils), additive CNS depression with other drugs
don’t develop tolerance to constipation and miosis
Treatment of opioid toxicity/overdose
naloxone or naltrexone which are opioid receptor antagonists
Mechanism of butorphanol
kappa-opioid receptor agonist and mu-opioid receptor partial agonist so can produce analgesia
Use of butorphanol
severe pain (e.g. migraine, labor) causes less respiratory depression than full opioid agonists
Toxicity of butorphanol
can cause opioid withdrawal symptoms if patients is also taking full opioid agonist (competition for opioid receptors)
overdose not easily reversed with naloxone
Mechanism of tramadol
weak opioid agonist; also inhibits 5-HT and NE reuptake (works on multiple NTs)
Use of tramadol
chronic pain
Toxicity of tramadol
similar to opioids
decreases seizure threshold
serotonin syndrome
