Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Flashcards
Are NSAIDs weak acids or bases?
They are weak organic acids and are therefore absorbed rapidly in the stomach and small intestine. The stomach has a lower pH than the small intestine and, therefore, more drug is in the absorbable unionised form. However, the main source of absorption is the small intestine due to its larger surface area.
Do NSAIDs have high, moderate or low bioavailability?
NSAIDs have a high bioavailability due to limited first-pass hepatic metabolism. However, bioconversion is mostly hepatic.
Are NSAIDs highly or poorly protein bound? What is the potential adverse consequence of this?
They are highly protein-bound molecules and, as a result, can displace other protein-bound medications, leading to increased free drug concentrations and increased risk of adverse events, e.g. displacement of warfarin from albumin leading to an increased risk of bleeding.
What co-concurrent medications are known to increase bleeding risk if taking NSAIDs?
They may increase bleeding risk if taken with anticoagulants, selective serotonin release inhibitors or other NSAIDs. There is specific interaction with warfarin as it is highly protein bound, therefore displaced by NSAIDs. This can increase the effect of warfarin on INR.
Name 2 drugs that NSAIDs are known to increase risk of toxicity.
Lithium
Methotrexate
Regarding physiology and the pharmacology of NSAIDs (true or false):
COX-1 is inducible
False. COX-2 is inducible.
Regarding physiology and the pharmacology of NSAIDs (true or false):
COX-1 is found in high concentration in the stomach
True
Regarding physiology and the pharmacology of NSAIDs (true or false):
COX-1 inhibition is responsible for the desired therapeutic effects of NSAIDs
False. COX-2 is largely responsible for the beneficial therapeutic effects.
Regarding physiology and the pharmacology of NSAIDs (true or false):
COX-2 inhibitors lead to increased cardiovascular risk
True
Regarding the pharmacokinetics of NSAIDs (true or false):
NSAIDs cannot be administered parenterally
False. Some NSAIDS, e.g. parecoxib and diclofenac, are available as IV preparations.
Regarding physiology and the pharmacology of NSAIDs (true or false):
Arachidonic acid is derived from the cellular phospholipid bilayer
True. NSAIDs reduce inflammation by inhibiting the enzyme cyclooxygenase (COX), which converts arachidonic acid into prostaglandins, thromboxanes, and prostacyclins
Regarding the pharmacokinetics of NSAIDs (true or false):
NSAIDs are weak organic bases
False. NSAIDS are weak acids.
Regarding the pharmacokinetics of NSAIDs (true or false):
NSAIDs are mainly absorbed in the stomach
False. NSAIDS are mainly absorbed from the small bowel. This is despite them being weak acids and therefore unionised in the stomach. However because of the much higher surface area, most of the absoprtion is done in the small intestine.
Regarding the pharmacokinetics of NSAIDs (true or false):
NSAIDs undergo limited first pass metabolism
True
Regarding the pharmacokinetics of NSAIDs (true or false):
NSAIDs are highly protein bound
True
Regarding physiology and the pharmacology and clinical uses of NSAIDs (true or false):
NSAIDs produce their antipyretic actions through increased prostaglandin synthesis in the CNS
False. NSAIDs produce their antipyretic effects by inhibiting the production of prostaglandins.
Regarding physiology and the pharmacology and clinical uses of NSAIDs (true or false):
Thromboxane A2 (TxA2) is a potent platelet inhibitor
False. Thromboxane A2 is a potent platelet aggregator.
Regarding physiology and the pharmacology and clinical uses of NSAIDs (true or false):
NSAIDs cause bronchospasm in prone asthmatics due to increased leukotriene production
True
Regarding physiology and the pharmacology and clinical uses of NSAIDs (true or false):
NSAIDs are safe to use in the antenatal period
False. NSAIDs can cause premature closure of the ductus arteriosis and oligohydramnios.
Regarding physiology and the pharmacology and clinical uses of NSAIDs (true or false):
NSAID use is a contraindication for neuraxial anaesthesia
False. Neuraxial techniques can safely be performed in patients on NSAIDs.
Regarding the safe use of NSAIDS (true or false):
NSAIDS may increase the risk of bleeding when concomitantly used in patients on warfarin
True
Regarding the safe use of NSAIDS (true or false):
NSAIDs are ideal analgesia agents in patients with chronic kidney disease
False. NSAIDs can cause acute on chronic renal failure in this patient group.
Regarding the safe use of NSAIDS (true or false):
Aspirin can safely be used in paediatric patients
False. There is a risk of Reye’s syndrome in paediatric patients
Regarding the safe use of NSAIDS (true or false):
NSAIDs may increase the possibility of lithium toxicity
True
Regarding the safe use of NSAIDS (true or false):
Proton pump inhibitors (PPIs) should be considered with long term NSAID use
True
