Pain and Analgesia Flashcards
What processes occur when there is tissue injury?
Release of inflammatory mediators (K+, H+, bradykinin, histamine, nitric oxide and serotonin and prostaglandins), activation of peripheral nociception too
What are some of the physiological processes present in neuropathic pain?
Altered ion channel expression –> hyper excited neurones –> excessive release of neurotransmitters with ectopic/spontaneous discharge
Name two excitatory neurone receptors?
glutamate and NMDA receptors
Name three inhibitory neuronal pathways
GABA, opioid and monoaminergic
When is pain defined as chronic?
If it lasts longer than 6 months
Name three weak opiods
Codeine, dihydrocodeine and tramadol
Name 4 strong opioids
Morphine, hydromorphone, fenatyl and methadone
What is the mechanism of action of diclofenac?
NSAID, inhibits COX-1/2 to prevent PG synthesis
What are the potential side effects of diclofenac?
May have side-effects on the kidneys, GI tract, platelets and bleeding
What is the mechanism of action of tramadol?
Weak opiod which acts to modulate monoaminergic pathways
What are the potential side effects of tramadol?
Nausea, vomiting, dizziness and sweating
What is the principle of action behind the use of opioids?
These drugs mimic analgesic peptides normally found in the body such as endorphins, dynorphins and enkaphalins
What are the three opioid receptor types?
u, k and delta
Where are opioid receptors found?
CNS and in the gut
Why may naloxone be used alongside opioids?
To prevent opioid-induced constipation as it has a greater affinity for opioid receptors in the gut
