Exam Flashcards
(54 cards)
Opioid drugs are _________ _______ ; they reduce pain without producing unconsciousness
narcotic analgesics
In contrast to analgesics, anesthetics reduce all sensations by…
depressing the central nervous system and producing unconsciousness
“Opiates” vs “Opioids”?
Opiates - specific substance derived directly from opium poppy
Opioids - broader term, including opiates, synthetic substances, and endogenous peptides
What was the Law passed in 1914 which made non-prescribed opioids illegal?
Harrison Narcotics Tax Act
What is the primary active ingredient in Opium?
Morphine; alongside codeine, thebaine, and narcotine
What pharmacokinetic changes occur due to simple modifications in the morphine molecule?
potency, duration of action, and oral effectiveness
Heroin is converted to morphine in the brain; why is heroin more potent and is able to reach the brain faster?
Because it is more lipid soluble
Distinguish partial agonists and neutral antagonists.
Partial agonists: bind readily to receptors but have less efficacy
Neutral antagonists: can prevent or reverse the effect of opioids (naloxone and nalorphine)
What were the criteria for receptor identification?
specificity, saturability, reversibility and high affinity, and biological relevance
What are the four opioid receptor subtypes and what is their general function?
(all four metabotropic)
Mu receptor - high affinity for morphine; wide distribution in brain and spinal cord
Delta receptor - forebrain; modulate olfaction, motor integration, reinforcement, and cognitive function
Kappa receptor - striatum and amygdala, hypothalamus and pituitary; regulate pain perception, gut motility, and dysphoria
NOP-R (Nociceptin/Orphanin FQ Receptor) - CNS and PNS; analgesia, feeding, learning, motor function, and neuroendocrine regulation
Compare PZM21 to Morphine. (Using Box 11.1)
PZM21 is an analgesic with reduced bad side effects (regarding constipation, respiratory depression, and conditional addiction), exhibiting longer duration
How are pain and stress linked?
Stressors increase both corticotropic-releasing factor (CRF) and POMC, which is a propeptide for endogenous opioids
Opioid receptor-mediated cellular changes are…
Inhibitory
What are the three inhibition techniques for opioid receptors?
Postsynaptic inhibition: opens K+ channels (hyperpolarization)
Axoaxonic inhibition: closes Ca2+ channels (decrease amount of transmitter released)
Presynaptic autoreceptors: reduce release of a co-localized transmitter
Distinguish Early vs Late pain.
First (early) pain: immediate, sensory component; conduct action potentials rapidly
Second (late) pain: emotional component; slower transmission
What are nociceptors?
Networks of free nerve endings that are sensitive to intense pressure, extreme temperature including heat and cold, electrical impulses, cuts, chemical irritants, and inflammation
What are noxious stimuli?
A sensory experience strong enough to produce a pain perception and a stimulus which potentially be dangerous to the body
How do opioids inhibit pain transmission?
Opioids mimic inhibitory action of endogenous opioids, reducing transmission of pain signals at the spinal cord in two ways:
Inhibitory spinal interneurons (release endorphins to inhibit activation of spinal projection neurons) and Descending modulatory pathways (inhibit projection neuron or excitatory interneuron, or excite inhibitory opioid neuron; most important pathway originates in the PAG in the midbrain)
Where else does opioid activity occur?
supraspinal locations, such as sensory areas, limbic structures, and hypothalamus; may be responsible for the emotional component of pain
What is the thought of negative correlation between opioid activity and pain scores?
The greater the mu-opioid receptor activation, the lower the individual’s sensory pain scores
How do opioids affect dopamine signaling and where?
Opioids inhibit inhibitory GABA cells, increasing mesolimbic cell firing and DA release in the nucleus accumbens (NAcc)
How did opioids become an epidemic? What are current street options for the drugs?
misleading and aggressive marketing of OxyContin to doctors and patients by Perdue Pharma; heroin and counterfeit pills are now being adulterated with illicitly manufactured fentanyl
What is the treatment for opioid addiction?
biopsychosocial approach; detox is first step, possibly assisted by methadone (which reduces symptoms to a comfortable level) or buprenex (an opioid partial agonist)
Where is cocaine derived from?
alkaloid in leaves of the shrub Erthroxylon coca, native to South America, which is then converted to a HCl salt and crystallized
