NSAIDs Flashcards
What’s their MoA?
Inhibits COX enzymes involved in prostaglandin synthesis.
How long does it take to reach its full effect?
- mild to moderate pain relief - with first dose
- analgesic full effect - takes 1 week
- Anti-inflammatory effect - takes 3 weeks
Which drugs are selective COX-2 inhibitors?
- Celecoxib
- Etoricoxib
- Parecoxib (post-operative pain)
Pregnancy?
AVOID. Esp in 3rd trimester.
It delays labour, causes pulmonary HTN in new-born child, premature closure of foetal ductus artiosus.
SEs?
- asthma and NSAIDs
- NSAID hypersensitivity
- Photosensitivity with topical NSAIDs
- nephrotoxicity
- Na and fluid retention
NSAIDs and asthma
Take caution as it may worsen asthma.
Can cause bronchospasm.
C/I if history of asthma attack with NSAIDs
NSAID hypersensitivity
C/I if history of sensitivity to NSAIDs or aspirin = bronchospasm, rash, angioedema, hives and rhinitis
Photosensitivity with topical NSAIDs
Esp. ketoprofen
Nephrotoxicity?
Caution in renal impairment
NSAIDs reduce glomerular filtration (eGFR) and are renally cleared
Temporarily stop on “sick days” = acute kidney injury
Na and fluid retention
Caution in renal and liver impairment, congestive heart failure, HTN
Interactions?
Increased risk of acute kidney injury
- ACEi, cyclosporin, tacrolimus, diuretics
Increased risk of bleeding
- warfarin, DOACs, antiplatelet, low-dose aspirin, heparin, SSRI, venlafaxine, steroids
Reduced renal excretion = increased toxicity
- methotrexate, Li
Increased risk of high K+
- K+ sparing diuretics
Increased risk of convulsions
- Quinolones
Enhanced effect of sulfonylureas
NSAIDs antagonise hypotensive effects
- BB, CCB, ACEi, nitrates, alpha-blockers, A2RA
Regarding GI toxicity in NSAIDs, which NSAIDs has the highest risk?
Ketoproen
Ketolorac
Piroxicam
Regarding GI toxicity in NSAIDs, which NSAIDs has the medium risk?
Naproxen
Diclofenac
Indomethacin
Regarding GI toxicity in NSAIDs, which NSAIDs has a low risk?
Ibuprofen
Regarding GI toxicity in NSAIDs, which NSAIDs has the LOWEST risk?
COX-2 selective NSAIDs
What would you give to pts (e.g. elderly) if they are at high risk but need to take NSAIDs?
PPI for gastroprotection
Pts over 45 years who are prescribed NSAIDs for lower back pain should be co-prescribed PPIs.
GI TOXICITY in NSAIDs - pt counselling and CI?
- causes stomach irritation, thus, take with or after food
GI bleeding/ulcers/perforation:
C/I - - active GI bleeding/ulcers
- ketoprofen/piroxicam/ketorolac - any history
- other non-selective NSAIDs >2 eps
- history of NSAID-induced ulcer/bleeding
Regarding cardiovascular events in NSAIDs, which NSAIDs has the highest risk?
- high dose ibuprofen 2.4g OD
- dexibuprofen
- COX-2 SELECTIVE
- diclofenac / acelofenac
Low-dose ibuprofen and naproxen are associated with the lowest risk of CVS risk.
Why are cardiovascular events with NSAIDs dangerous?
There’s a small increased risk of thrombotic events, e.g. MI or stroke.
In severe HF => all NSAIDs are CI.
What are additional C/Is for NSAIDs in terms of cardiovascular events?
- IHD
- Cerebrovascular disease
- Peripheral arterial disease
- mild to severe HF
- Left ventricular dysfunction
- HTN
- pts with oedema for any other reason; may precipitate CHF
- pts with risk factors for CVD events
Monitoring?
BP (esp after dosing changes)
Renal function
LFT
Hb in those with risk factors for GI bleeding
Warning signs?
- black stools or coffee-ground vomit, suggesting chronic GI bleed
- iron-deficiency anaemia, suggesting chronic GI bleed (fatigue, dizziness, pale skin, SoB)
- progressive unintentional weight loss or difficulty swallowing
- pregnancy and breastfeeding
- swollen ankles or feet
- unexplained, persistent recent-onset dyspepsia
- worsening of asthma
Which NSAIDs have a preference for COX-2?
Meloxicam
Etodoloac
Nabumetone
Diclofenac
Which NSAIDs are non-selective?
Menfenamic acid
Ibuprofen
Naproxen
Indometacin
