Analgesics Flashcards
Define analgesia.
insensibility to pain without loss of consciousness.
Describe the MOA, therapeutic and adverse actions of opioid agonist analgesics, and opioid antagonists.
Agonist - full activation of receptor, dose increases and so does resp depression threshold inccreases.
Antagonist - binds to opiate receptor and blocks it. does not cause respiratory depression - reversal of overdose and allows breathing
Describe the MOA, therapeutic and adverse actions and nursing considerations of opioids
Opioids / mOrphine, cOdeine / Analgesic action of opioids include inhibition of substance P, closing the gate in the dorsal horn, thus inhibiting afferent transmission and altering perception and emotional responses to pain.
AR - vitals low [HR, RR, BP], sedating, high abuse potential, physical and mental dependence, CNS depressent
Nursing indic
WH for RR below 12
Vitals monitor incl sedation score
Constipation - laxatives, high fibre diet
Describe the MOA, therapeutic and adverse actions and nursing considerations, contra and pt education of NSAIDS
NSAIDS(ibuprofen, celecoxib) NON opioid analgesic
Antipyretic(for fever) and anti flammatory. MOA the inhibition of the enzyme COX which inhibits prostaglandins decreasing inflammation, pain and fever [prostaglandin functions]
Dec pain, inflammation and fever
Contra
Dec renal/liver function
Inc bleeding risk
AR GI bleeding HTN Causing bronchospasm Blood clots Inc bleeding risk Dec kidney function
Pt education
Take w food never on empty stomach
If pt has tinnitus then sign of toxicity on NSAIDS.
Hydration to assist kidneys
Nursing cons
Monitor kidney function and platelets
Encourage adequate hydration
Discuss lifespan considerations for pain management
Opioids - sedating, check for elferly, constipation
Discuss the WHO analgesic ladder and side effects to step 2 and 3 and its purpose
Purpose: framework used to guide the pharmacological treatment of pain in chronic pain and palliative care patients.
Step 1 [mild 1-3] non opiod (NSAID or paracetamol) + non pharm adjuvents Step 2 [moderate 4-6] non opioids (paracetamol + NSAID + weak opioid like codeine or tramadol) + non pharm adju Step 3 (severe 7-10) Strong opioids (morphine, fentanyl, oxy) non pharm adju.
Side effects to 2 and 3 - constipation, nausea and vomiting, sedation, resp depression.
Three primary types of opioid receptors and the main one
Mu*
Kappa*
Delta*
Main one is MU
What is responsible for this mechanism
stimulation of opioid receptors in the dorsal horn in the spinal cord inhibits the release of substance P
Decreased substance P inhibits the afferent transmission of pain signals to the cortex
“closes the gate”
Alters the perception of pain
Opioid agonists
function of prostaglandin
- prosta are a group of lipids made up @ site of tissue damage. metabolised by cox enzyme and action in pain is to dec threshold of nociceptors. physiological function - inflammation through vasodilation, platelet aggregation, maintain renal blood flow.
NSAIDs should be avoided in late pregnancy due to:
the prolongation of gestation and labour
Opioid analgesics are best used in which type of pain?
Opioid analgesics are effective and commonly used for the management of severe acute pain.
Opioids can induce the following adverse effects
biliary colic, constipation, pruritus (itching)
Stimulation of the following opioid receptors is associated with analgesia
Mu, Kappa (K) and Delta (D)
The synthetic analgesic tramadol acts by
binding to the mu opioid receptors
inhibiting the reuptake of noradrenaline
inhibiting the reuptake of 5-HT (serotonin)
Tissue injury or tissue inflammation is most likely to cause which type of pain
nociceptive
Acupuncture and transcutaneous electrical nerve stimulation (TENS) increase endorphin release. T/F
True
Endorphin release in the body is higher after acupuncture and TENS and both effects may be reversed by the use of naloxone, an opioid antagonist.
Compared to naltrexone, the opioid antagonist naloxone has a longer duration of action.
T/F
F
Naloxone is a short-acting opioid antagonist whereas naltrexone is a long-acting opioid antagonist.
Mild analgesics should be used initially in managing all types of pain. Stronger analgesics (e.g. opioids) should be reserved for when pain becomes more severe. T/F
F
More severe pain can be treated with higher doses of opioids and/or combinations of analgesics.
Regular use of NSAIDs over a long period may cause tolerance or dependence.
T/F
F
The analgesic action of NSAIDs is peripheral and spinal, it does not cause tolerance or dependence or modify psychological reactions to pain. whereas opioids does!
Sharp pain is transmitted from the peripheries to the spinal cord via A-delta fibres.
T/F
A-delta fibres transmit sharp, transient fast pain and C-fibres transmit burning, aching, slow, visceral pain.
When codeine is taken into the body, it is metabolised to morphine.
T/F
T
Codeine is a pro-drug, being rapidly metabolised in most people to morphine. However, 6-10% of the Caucasian population lack the enzyme to metabolise codeine, hence it has no analgesic effect.
A dose of an opioid may have to be increased to control the pain in some individuals with cancer. This is because they have developed drug:
tolerance
Naloxone, the opioid antagonist, has the greatest activity on which receptors?
Mu
NSAIDs inhibit the synthesis and release of:
prostaglandins
Physiological responses to acute pain include:
Increased blood pressure, increased pulse rate, dilated pupils and perspiration are physiological responses to acute pain.
Sign/s that a child younger than 2 years might be in pain include/s:
Decreased acitvity, anorexia or crying
The mechanism of the analgesic action of opioids (e.g. morphine) includes
Analgesic action of opioids include inhibition of substance P, closing the gate in the dorsal horn, thus inhibiting afferent transmission and altering perception and emotional responses to pain.
Which group/s of patients is/are often under-treated for pain?
minority groups, women under 50, men and wome over 70
Chronic pain is best treated if analgesics are given only when necessary (prn). T/F
F
Analgesics should be given on a regular basis in chronic pain to optimise blood levels and reduce the conditioning reaction in which periods of pain lead to drug-seeking behaviours.
Compared to morphine, tramadol is less likely to cause respiratory depression and drug dependency. T/F
This centrally acting analgesic, which is not chemically related to opioids, may have a lesser potential for respiratory depression and drug dependency.
For mild to moderate pain in children, aspirin is the analgesic of choice.
T/F
Aspirin should not be used in children because of its association with Reye?s syndrome, a rare but serious disorder due to damage to hepatic mitochondria.
