Lectuer 16: analgesics Flashcards
What is pain?
-unpleasant sensory and emotional experience assoc with tissue damage or non tissue damage
- subjective, difficult to quantify
- similar harm can vary between patients
What must health professionals be aware of with regards to patient and pain?
accept patients response to pain
- be observant
- show empathy
- consider if injury matches the level of pain reported
- know the personality of the patient
How is pain management carried out?
-must be individualised to patient based on cause, severity of pain and chronicity
What is the Nociceptive pain pathway?
- begins with tissue damage either due to mechanical, chemical or chemical hurt
- pain signals are generated and are sent to the dorsal horn, then CNS
- when the brain receives the signal, it responds by sending a descending inhibtion to relieve the pain message.
What does the nociceptive pathway tell us?
- that there is more than one way to stop the pain.
- therefore local anaesthetis can block the nerve transmission at two sites
What are other possibilities for treating pain?
- reduce signals at local site
- reduce signals transffered to CNS
- enhance descending inhibition pathway
What are non-pharmacological alternatives to treating pain?
- transcutaneous electrical nerve stimulation
- electrica stimulation to manage the pain
- relaxation therapy (can reduce pain from scale 10 to scale 3)
- nerve block
- acupuncture: may induce activation of endogenous opiod system
What is TENS?
transcutaneousl electrical nerve stimulation
-electrodes are placed on skin to generate an electrical force that will help to relieve the pain
What are analgesis?
- drugs that mediate pain relief
- we use different drugs to treat different types of pain e.g. for mild-mod pain we use mild drugs.
Why is it important to save the stronger drugs for more severe pain?
this increases the pain tolerance and will also help to manage the pain feelings
What are the two most common classes of analgesics?
Opioids and non-narotics
What are opioids?
- substances (exogenous or endogenous) which bind to opiiod receptors
- pharmacologically similar to opium or morphine
- e.g. codeine, morphine, tramadol,
What are endogenous opioids?
-opioids which are naturally relied from the human body and can bind to receptors
What are exogenous opioids?
opioids which you have to take as either a drug or other material
What are primary analgesics used for?
- cough suppressants and to control diarrhoea
- hence elderly often use opioids to treat other medical conditions
- provides analgesic without anti-pyretic effect
What is a common error with mild opioid use?
-the overestimation of the amount of drug used for pain killer purposes
What are are examples of endogenous opioids?
- endorphins
- dynophins
- encephalins
- nociceptins
these bind to your opioid receptors and help to explain the benefits/evidence of acupuncture.
What is the mechanism of action of opioids?
- bind to opioid receptors which are widespread around the CNS
- highest concentration of receptors is in the pons and pain modulation pathways
What are the 3 subtypes of opioid receptors?
- mu
- delta
- kappa
these are distributed differently in different tissues and have different physiological effects in the body.
What is the mu opioid receptor?
- mainly located in brain, spinal cord
- causes analgesia, respiratory depression, euphoria, addiction
- blocks all pain messages
What is the kappa opioid receptor?
- found in brain and spinal cord
- causes analgesia, sedation,
- blocks all non thermal pain messages
What is the delta opioid receptor?
- found in the brain
- causes analgesia, anti-depression, dependence
Which opioid receptor should be activated/targeted in order to manage pain but reduce the risk of addiction?
kappa receptor
Which opiod receptor should be used to avoid side effects like respiratory depression?
mu receptor
