ANLEGESICS Flashcards
what are the 3 types of pain
There are three main types of pain—nociceptive, neuropathic and nociplastic pain.
what is neropathic pain
- Neuropathic pain arises as a direct consequence of a lesion or disease affecting the somatosensory nervous system.
what is Nociplastic pain
- Nociplastic pain is a diagnosis of exclusion. It is characterised by altered or abnormal function of the nociceptive pathways or cerebral cortex in the absence of a nociceptive stimulus or neuropathic lesion.
MS, Fibromyalgio
Nociceptive pain
- Nociceptive pain arises from activation of nociceptors due to actual or threatened tissue damage.
ei BONE FRACTURE or BURN
acute pain vs chronic pain
Acute pain usually occurs due to an acute illness (eg appendicitis), or following surgery or trauma. It lasts LESS than 3 months, **and there is an expectation of recovery and return to usual function.
Chronic pain is a complex medical condition were pain persists or recurs for LONGER THEN 3 months. It is affected by multiple dimensions of a patient’s life, including their: social environment, thoughts and emotions, physical health, sleep and nutrition
types of NON-OPIOD anlegesic
asprin
NSAID
what is asprin used for
Aspirin is used to manage mild to moderate pain at higher doses of 300–900 mg every 4–6 hours.
At lower doses of 100mg daily it has antiplatelet action. It has analgesic, antipyretic, anti-inflammatory and antiplatelet actions.
It is a nonselective NSAID, preventing synthesis of prostaglandins by non-competitively inhibiting both forms of cyclo-oxygenase, COX1 and COX2
high dose for migraine, low does antiplatelet
contraindications of ASPRIN
people who have asthma where it can cause bronchospasm. It is also contraindicated
in patients with active bleeding such as peptic ulcer disease.
PANADOL
Paracetamol is
used to manage mild to moderate pain.
MOA stops central prostaglandin synthesis and modulation of inhibitory descending serotonergic pathways.
Paracetamol is hepatotoxic in overdose, therefore in patients with chronic liver disease, should refrain/
use wcaution.
well tolerated but in very rare cases can result in hypersensitivity safe to use in pregnancy and breastfeeding.
what are the side/adverse effects of opoid anlgesia
nausea and vomiting
dyspepsia,
drowsiness,
dizziness,
headache,
orthostatic hypotension,
itch, dry mouth
constipation
Opiod mode of action
- Opioid analgesics act on receptors in the CNS and GIT
- Opioid analgesics include morphine, codeine, and fentanyl. These drugs work by binding to opioid receptors in the brain, which reduces the perception of pain
Buprenorphine
Buprenorphine is a weak partial mu-opioid receptor agonist and a weak kappa-opioid receptor antagonist used for the treatment of severe pain
s/e = constipation, sedation
non-selective competitive opioid receptor antagonist.
(blocks pain receptor).
Types of pain
Nociceptive pain - pain resulting from actual or threatened tissue damage.
Neuropathic pain - pain results from impaired somatosensory nervous system
Nociplastic pain - pain resulting from altered or abnormal function of nociceptive pathways or cerebral cortex.
Opioid analgesics
Indication:
- Moderate to severe pain, usually acute pain, or cancer-associated pain
Mechanism of action:
- Opiods bind to opiod receptors, namely mu, delta, kappa receptors. Receptors are found in the brain, GIT, and spinal cord
-
- Most are mu receptors, therefore called ‘mu agonists’
- Tramadol and tapentadol produce analgesia via non-opioid pathways
Pure agonists:
- Morphine
- Oxycodone
- Codeine
- Tramadol
- Tapentadol
- Methadone
- Pethidine
Partial agonists:
- Buprenorphine
Adverse effects:**
- Constipation
- Respiratory depression
- Sedation
- Nausea and vomiting
- Dispepsia
Specific opioids:
- Oxycodone-naloxone (Targin) - naloxone helps with opioid-induced GI effects such as constipation
Practice Points:
- used in combination with laxatives
- tapering off when coming off the drugs
- partial agonists have a ceiling effect
- monitor pain and sedation
Intrapartum pain management - anelgesia
- Nitrous oxide and oxygen
- Systemic opioids
- Neuraxial anaglesia