Which type of analgesic drug reduces inflammatory pain by dampening down the inflammatory response?
inhibit prostaglandin production by inhibiting COX1/2
How do NSAIDs work?
Reduce production of prostaglandins
Prostaglandins produce which three effects?
Name five non-selective NSAIDs.
How can you tell that an NSAID is COX-2 specific?
It will be called something-coxib
What are some side effects of NSAIDs?
Peptic ulceration > GI bleeding
Cardiovascular problems (COX-2 only)
COX-2 inhibitors (-coxibs) aren't often used because they contribute to cardiovascular disease - how?
increase chance of DVT > PE, stroke
Which type of analgesic drug reduces pain by inhibiting nociceptive nerve transmission in the brainstem and posterior horn of the spinal cord?
Which type of analgesic drug reduces pain by targetting ion channels involved in nerve damage and inflammation?
Which type of analgesic drug works by inhibiting serotonin and noradrenaline reuptake?
Which ion channel is blocked by many antiepileptic drugs e.g carbamazepine?
Describe the WHO analgesic ladder.
1. Non-opioid +/- adjuvant
2. Weak opioid +/- non-opioid +/- adjuvant
3. Strong opioid +/- non-opioid +/- adjuvant
Is paracetamol an NSAID?
NSAIDs are anti-inflammatory, anti-pyrexial and analgesic - paracetamol isn't anti-inflammatory
What is the difference between pain and nociception?
Pain is the experience of suffering
Nociception is the nervous system's way of conveying pain signals to the brain
What is the Gate Control Theory?
Pain is transmitted by SMALL FIBRE sensory nerves
Mostly everything else is transmitted by LARGE FIBRE sensory nerves
if the large fibre nerves are transmitting impulses, inhibitory interneurons stop small fibre impulses (i.e pain impulses) from going any higher
i.e if you're bombarded with other sensory information, your perception of pain is reduced
In the Gate Control Theory, nerve impulses from large (Aα and Aß fibres) sensory fibres activate the ___ interneurone, stopping the transmission of pain signals.
Which types of nerve fibre are classed as large fibre sensory nerves?
A-alpha and A-beta fibres are involved in dampening down nociceptive signals in the Gate Control Theory.
Which senses are these fibres responsible for?
A-alpha = proprioception
A-beta = skin mechanoreceptors
Which types of nerve fibre are classed as small fibre sensory nerves?
Which sensations do they control?
Pain, temperature, itch
Which inhibitory neurotransmitter is involved in the Gate Control Theory?
Which excitatory neurotransmitter is involved in the Gate Control Theory?
The Gate Control Theory is an example of (afferent / efferent) pain modulation.
ascending tracts, sensory
Pain modulation descending from the brain is known as (afferent / efferent) modulation.
Which area of the brainstem has an analgesic effect when stimulated?
Where specifically in the brainstem is it found?
Periaqueductal grey matter
The periaqueductal grey area of the midbrain is an efferent regulator of pain.
Apart from electrical stimulation, what activates it?
What is the result of activation of the periaqueductal gray matter?
Nociceptive signals from the posterior horn are INHIBITED
i.e perception of pain is reduced
because Nucleus raphe magnus and Locus coeruleus are activated
What are the body's endogenous opioids called?
When activated by electrical impulses or opioids, the periaqueductal gray area activates two other brain areas.
What are they called?
Nucleus raphe magnus
Which chemicals are released by the nucleus raphe magnus?
What is the end result of this chemical release?
inhibition of nociceptive transmission, analgesia