Lecture 7 review Flashcards
Pathway of pain
1) Transduction
2) Transmission
3) Perception
4) Modulation
Transduction
- Noxious stimuli cause cell damage with the release of sensitizing chemicals
- Prostaglandins
- Bradykinin
- Serotonin
- Substance P
- Histamine - These substances activate nociceptors and lead to generation of action potential
Transmission
Action potential continues from
- site of injury to spinal cord
- spinal cord to brain stem and thalamus
- thalamus to cortex for processing
Perception
Conscious experience of pain
Modulation
Neurons originating in the brain stem descend to the spinal cord and release substances (e.g. endogenous opioids) that inhibit nociceptive impulses
PAIN acronym
Pattern
Area
Intensity
Nature
Ceiling effect
Increasing the dose beyond an upper limit provides no greater analgesia
“Step 1” drugs
Non-opioid analgesics
- aspirin and other salicylates
- NSAIDs
- acetaminophen
Prototype
Drug that best represents a class of drugs
Prodrug
Drug that requires conversion to its active form
Opioid defintion
A general term that is defined as any drug, natural or synthetic, that has actions similar to those of morphine
“Step 3” drugs
- Most are mu-receptor agonists
- potent
- no analgesic ceiling
- can be delivered via many routes
Three main classes of opioid receptors
- mu receptors
- kappa receptors
- delta receptors
Mu receptors
Analgesia, respiratory depression, euphoria, sedation, and physical dependence
Kappa receptors
Analgesia and sedation