Analgesic Medications Flashcards
What is nociceptive pain?
Pain that arises from actual or potential tissue damage and is typically caused by the activation of nociceptors, specialised nerve endings that detect harmful stimuli such as heat, pressure, or chemicals.
What is acute pain?
Short-term pain that typically occurs suddenly in response to an injury or illness and serves as a warning signal to the body
What is chronic pain?
Persistent pain that lasts beyond the expected healing time, usually for at least three months, and often has a complex underlying cause.
What is neurogenic pain?
Pain caused by damage or dysfunction of the nervous system, characterized by abnormal sensory processing and often described as burning, shooting, or tingling.
What is psychogenic pain?
Pain that is influenced or caused by psychological factors, such as emotional distress, anxiety, or depression, without a clear physical cause.
What are the four steps of the pain pathway?
- Transduction
- Transmission
- Perception of pain
- Modulation
As you age, a natural decline in the number and function of A-fibers can occur. What is the effect of this?
The decrease in A-fibers can lead to a decline in sensory perception and sensitivity, particularly in the affected areas. This may result in reduced tactile acuity, decreased ability to detect fine details, and impaired response to stimuli such as heat or pressure.
What is the gate control theory of pain?
A theory that explains how pain perception is influenced by a “gate” in the spinal cord. The gate can be opened or closed by different factors, such as the activation of large or small nerve fibers and cognitive/emotional processes. When the gate is closed, it reduces the transmission of pain signals to the brain, resulting in less perceived pain.
What are the three primary types of opiod receptors?
Mu
Kappa
Delta
With IV morphine administration, what must be avaliable?
Naloxone and oxygen
IV morphine/fentanyl infusions are always done through what?
And how often are resp rates recorded?
A pump
Resp rate recorded hourly throughout the infusion
Observations for a patient on IV morphine must include what?
Pain score, 0-5.
Sedation score, 0-3
Respiratory Rate
BP and pulse
And all further observations to ensure a EWS calculation
What are some key points of codeine and dihydrocodeine?
Less potent than Morphine
Converted to Morphine by the liver enzyme CYP2D6 (prodrug)
Constipating ++
Often combined with Paracetamol
What is pethidine?
Pethidine is a synthetic opioid analgesic used for the treatment of moderate to severe pain. It works by binding to opioid receptors in the central nervous system, altering the perception of pain and providing relief. (has a short duration of action).
What is tramadol?
Tramadol is a synthetic opioid analgesic used to treat moderate to moderately severe pain. It works by binding to opioid receptors in the brain, altering pain perception and providing relief. It is a weaker opiod.
What is oxycodone?
Oxycodone is a potent opioid analgesic used for the management of moderate to severe pain. It works by binding to opioid receptors in the central nervous system, altering pain perception and providing pain relief. It is a stronger opiate.
What is fentanyl?
Fentanyl is a potent synthetic opioid analgesic, meaning it is a strong pain medication that is man-made. It is used for managing severe pain, particularly in cases where other opioids may not be effective. Fentanyl works by binding to opioid receptors in the brain, altering pain perception and producing a powerful pain-relieving effect. Due to its potency, fentanyl carries a high risk of overdose and is classified as a controlled substance.
What is the halflife of naloxone?
1 hour which is shorter than opiod agonists
What are NSAIDs?
Nonsteroidal anti-inflammatory drugs (NSAIDs) are a class of medications commonly used to relieve pain, reduce inflammation, and lower fever. They work by blocking the production of certain chemicals in the body that contribute to pain and inflammation.
Examples: Diclofenac sodium (Diclax SR, Voltaren),
Ibuprofen (Brufen)
Why do NSAIDs trigger/worsen asthma symptoms?
This may be due to disruptions in leukotriene balance, reduced bronchodilation caused by inhibited prostaglandin production, and the specific condition known as aspirin-exacerbated respiratory disease (AERD).
What is an easy way to think about NSAIDS and their MOA?
Think of COX as a factory that produces substances (prostaglandins) responsible for pain and inflammation. NSAIDs act like a switch that turns off this factory, so fewer of those substances (prostoglandins) are produced. This helps relieve pain, reduce swelling, and bring down fever.
Why do NSAIDS cause an increased risk of MI? (4)
Inhibition of enzymes: NSAIDs inhibit enzymes involved in producing substances that regulate platelet function and blood clotting. This disruption can increase the risk of blood clots and subsequent heart attacks.
Blood pressure elevation: Certain NSAIDs, particularly COX-2 inhibitors, can raise blood pressure, increasing the strain on the cardiovascular system and the risk of heart attacks.
Fluid retention: NSAIDs can cause fluid retention, which can add to the workload of the heart and potentially raise the risk of cardiovascular events.
Medication interactions: NSAIDs may interact with other medications used for cardiovascular conditions, further increasing the risk of bleeding or clotting abnormalities.
Why do NSAIDs cause a reduction in GFR leading to fluid retention
Prostaglandins play a role in maintaining the normal functioning of the kidneys, including the regulation of blood flow to the kidneys and the balance of salt and water. When prostaglandins are suppressed, blood flow to the kidneys may be reduced, leading to a decrease in GFR.
What is the patient education re NSAIDs?
Take with food, do not administer with aspirin, and be aware that NSAIDs can alter the effects of other drugs eg Digoxin and warfarin.
