Analgesics Flashcards
Nociception
detection of noxious stimuli or stimuli that are capable of damaging tissue
what is important to remember about pain?
it is a personal and individual experience
Selectively blocks the sensation of pain without blocking other symptoms or loss of consciousness
analgesic
blocks nerve conduction and all local sensations including pain
local anesthetic
causes loss of sensations and consciousness
general anesthetic
At which site of action do opioids have their greatest effect?
at the higher centres of the CNS
on which of the pain processes do opioids exert their effect?
on perception and modulation (transmission)
What receptors do opioids bind to?
opioid receptors
Opiate
any drug derived from opium (morphine, codeine)
all opioid analgesics are?
full agonists or partial agonists at mu and kappa receptors
examples of full agonist opioids?
morphine, codeine and fentanyl
Example of partial agonist opioid?
butprenorphine
where are mu receptors located?
in the brain (cortex, medulla, thalamus, limbic system, amygdala) and spinal cord
depression of the respiratory centre caused by opioids is due to which receptor?
mu
what is the prototype for opioid analgesics?
morphine sulphate
opioids are less effective in?
neuropathic pain
which type of receptor does morphine sulphate act on?
primarily mu
what is the half life of morphine sulphate?
2-4 hours
what are the most common non-narcotic analgesic?
NSAIDs
What are examples of adjuvants?
antidepressants, anti seizure drugs, glucocorticoids
why is severe asthma or other respiratory deficiencies contraindicated in morphine use?
because morphine can suppress respirations
what is the number one series adverse effect with morphine?
respiratory depression
how long do nausea and vomiting last with morphine
usually only for 1-3 days
does constipation associated with morphine use get a tolerance?
no
what is a med interaction of morphine?
CNS depressants such as antipsychotics, sedatives and alcohol. They can cause cumulative effects
what is an example of a moderate opioid analgesic?
codeine (3-methylmorphine)
Codeine is never given to?
children because they have an unpredictable metabolism
what is an example of an opioid antagonist?
naloxone
what is naloxone used for?
complete or partial reversal of opioid induced respiratory depression (overdose)
what is important to note about naloxone?
it has a shorter half life than morphine therefore the person could go back into respiratory depression. This means they may need more frequent dosing of naloxone
which pharmacological effects show tolerance?
analgesia and euphoria
state that develops in which an abstinence syndrome will occur if a drug is abruptly withdrawn
physical dependence
is opioid withdrawal lethal?
no
Oral forms of morphine should be?
taken with food to minimize GI upset
what does the nurse do if the patient’s respiratory rate drops to less than 12 per minute?
withhold dose and contact physician
respiratory depression may be manifested by?
- less than 12 breaths per min
- dyspnea
- diminished breath sounds
- shallow breathing
how do you manage constipation associated with opioid use?
ensure adequate fibre and fluid intake
