Pharmacology of Pain Flashcards
Which is the fastest type of pain?
Seconds to minutes
Nociceptive
Which is the longest type of pain?
Days to months
Change in trophic factors
What type of pain takes minutes to days?
Sensitisation of terminals at the injury site + delayed central sensitisation
What are the three types of pain?
Nociceptive
Inflammatory
Neuropathic
What are targets for treatment in the dorsal horn?
COX-2
Nitric oxide synthase (NOS)
Glutamate receptors (NMDA)
Opioid receptors
Name structures activated by nociceptive stimuli?
Spinal Cord Thalamus Somatosensory Cortec Anterior cingulate cortec Insula Amygdala Prefrontal cortex Hippocampus
What factors influence pain perception?
Cognition Mood Context Genetics Chemical + Structural Injury
How do opioids work?
Act on opioid receptor to produce morphine-like effects
Name two opioid peptides
enkephalin + dynoprhins
What are peptides targets for?
peptidases
Give three opioid receptors
Mu
Delta
Kappa
What do Mu, Delta and Kappa opioid receptors have in common?
all GPCRs involved in GABA-ergic neurotransmission
What are examples of of opioids?
Codeine
Methadone
Morphine
Tramadol
How does morphine work?
Activates K+ conductance + decreases Ca2+ conductance
What is the overall effect of morphine?
Decreases excitability + release of NTs
What receptors does morphine activate?
Mu
What are effects of opioids?
Analgesia Respiratory depression Lethargy Euphoria Hypotension Delayed gastric emptying
What order is the analgesic ladder?
- Non-opioids (aspirin + paracetamol)
- Mild opioids (Codeine)
- Strong opioids (morphine)
Give 4 examples of non-opioids
paracetamol
NSAIDS
Anticonvulsants
Antidepressants
What is the mechanism of paracetamol?
Reduces active oxidised form of COX-2
How does aspirin function?
COX 1 + COX 2 inhibitors
How does ibuprofen (and diclofenac work)
COX 1 + COX 2 inhibitors + other functions
What does Rofecoxib work?
Selective COX-2 inhibitor
What indications are there for NSAIDs?
Arthritis
Gout
Muscle spasms
