MSK/Pain Flashcards
(31 cards)
name three common NSAIDs
naproxen, ibuprofen, diclofenac
what are the indications to take NSAIDs?
‘As needed’ treatment of mild-to-moderate pain
Regular treatment for pain related to inflammation, particularly of the musculoskeletal system, e.g. in rheumatoid arthritis, severe osteoarthritis and acute gout.
how do NSAIDs work?
NSAIDs inhibit synthesis of prostaglandins from arachidonic acid by inhibiting cyclooxygenase (COX)
what are the two types of COX and whaat do they do?
COX-1: stimulates prostaglandin synthesis that
is essential to preserve integrity of the gastric mucosa; maintain renal perfusion (by dilating afferent glomerular arterioles); and inhibit thrombusformation at the vascular endothelium
COX-2: expressed in response to inflammatory stimuli. It stimulates production of prostaglandins that cause inflammation and pain.
The therapeutic benefits of NSAIDs are principally mediated by COX-2 inhibition and adverse effects by COX-1 inhibition
what are the side effects of NSAIDs?
GI toxicity
renal impairment
increased risk of cardiovascular (CV) events
fluid retention - worsen hypertension and heart failure
what are the contraindications to taking NSAIDs?
severe renal impairment, heart failure,
liver failure and known NSAID hypersensitivity
peptic ulcer disease or GI bleeding
what are the interactions with NSAIDs?
increased risk of NSAID-related adverse effects -
GI ulceration: low-dose aspirin, corticosteroids;
GI bleeding: anticoagulants, SSRIs, venlafaxine;
renal impairment: ACE inhibitors, diuretics.
NSAIDs increase the risk of bleeding with warfarin and reduce the therapeutic effects of antihypertensives and diuretics
what class of drug is codeine?
weak opioid
how does codeine work?
metabolised by cytochrome P450 enzymes to morphine and morphine-related metabolites - agonists of opioid µ-receptors,
what are the indications to take codeine?
Mild-to-moderate pain: as second-line agents when simple analgesics, such as paracetamol, are insufficient
what are the side effects of codeine?
nausea, constipation, abdo pain and drowsiness
neurological and respiratory depression
what are the contraindications to taking codeine?
significant respiratory disease, renal impairment and hepatic impairment, and also in the elderly.
what are the interactions with codeine?
other sedating drugs (e.g.antipsychotics, benzodiazepines and tricyclic antidepressants)
name two strong opioids
morphine, oxycodone
how do opioids work?
from activation of opioid µ (mu) receptors in the central nervous system. overall, reduce neuronal excitability and pain transmission
in the medulla, they blunt the response to hypoxia and hypercapnoea, reducing respiratory drive and breathlessness.
in MI and acute pulmonary oedema they may reduce cardiac work and oxygen demand, as well as relieving symptoms
what are the indications to take opioids?
For rapid relief of acute severe pain
For relief of chronic pain, when paracetamol, NSAIDs and weak opioids are insufficient
For relief of breathlessness in the context of end-of-life care.
To relieve breathlessness and anxiety in acute pulmonary oedema, alongside oxygen, furosemide and nitrates.
what are the side effects of opioids?
respiratory depression neurological depression nausea and vomiting constipation itching dependence
what are the contraindications to taking opioids?
hepatic failure and renal impairment and elderly
respiratory failure
biliary colic
what are the interactions with opioids?
other sedating drugs (e.g. antipsychotics, benzodiazepines and tricyclic antidepressants)
how does paracetamol work?
weak inhibitor of cyclooxygenase (COX)
appears to increase the pain threshold
reduce prostaglandin (PGE) concentrations in the thermoregulatory region of the hypothalamus, controlling fever
has specificity for COX-2 rather than COX-1
what are the indications to take paracetamol?
first-line analgesic for most forms of acute and
chronic pain
antipyretic that can reduce fever and its
associated symptoms
what are the side effects of paracetamol?
Steven-Johnson syndrome, toxic epidermal necrolysis
In overdose, paracetamol causes liver failure.
metabolised by cytochrome P450 enzymes to NAPQI
conjugated with glutathione before elimination
elimination. After overdose, this elimination pathway is
saturated, and NAPQI accumulation causes hepatocellular necrosis
how do you treat paracetamol overdose?
glutathione precursor - acetylcysteine
what are the contraindications to taking paracetamol?
Chronic excessive alcohol use (increased risk of liver toxicity); malnutrition, low body weight (reduced glutathione stores); severe hepatic impairment
