FB - NSAIDs Flashcards

1
Q

Compare and contrast the clinical actions of aspirin and ibuprofen.

A

Both aspirin and ibuprofen are:

(1) Anti-inflammatory
(2) Analgesic
(3) Antipyretic

Aspirin but NOT ibuprofen is an irreversible cyclo-oxygenase (COX) inhibitor and so a potent:
(4) Anti-platelet

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2
Q

What would be the usual analgesic choice for a child with mild to moderate pain?

A

Paracetamol would usually be the preferred first choice. Ibuprofen may be considered if greater anti-inflammatory action and analgesia is required.

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3
Q

Why does indometacin have a stronger anti-inflammatory profile than other nonselective NSAIDs?

A

Besides being a non-selective inhibitor of cyclo-oxygenase (COX), indometacin also inhibits phospholipase A2. Thus, indometacin reduces the production of leukotrienes, in addition to prostanoids, and so has a broader spectrum anti-inflammatory effect.

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4
Q

Which form of cyclo-oxygenase is expressed in inflammatory cells at sites of acute inflammation.

A

Inducible cyclo-oxygenase-2 (COX-2)

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5
Q

Why might a premature baby be administered indometacin?

A

To close the ductus

arteriosus

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6
Q

Why should etoricoxib be used with caution in a patient with active peptic ulcers?

A

Etoricoxib will impair wound healing and so pre-existing peptic ulcers are likely to persist.

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7
Q

What is the MOST common adverse effect of paracetamol at clinical analgesic doses?

A

Nausea

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8
Q

List THREE NSAIDs with greater selectivity for cyclo-oxygenase-2 (COX-2) over COX-1.

A

Etoricoxib, parecoxib (pro-drug of valdecoxib), celecoxib, meloxicam, mefenamic acid

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9
Q

Which NSAID has the greatest risk of precipitating an asthma attack in a patient with NSAID exacerbated respiratory disease (NERD)?

A

Aspirin because it is an irreversible inhibitor of cyclo-oxygenase (COX)

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10
Q

Which NSAIDs has the strongest anti-platelet effect?

A

Aspirin because it is an irreversible inhibitor of cyclo-oxygenase (COX)

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11
Q

What is the MOST common clinical use of aspirin?

A

Aspirin is still used clinically as an antiplatelet agent in patients at risk of thrombotic cardiovascular or cerebrovascular disease.

It is no longer commonly used as an analgesic or anti-inflammatory agent as other NSAIDs with a lower risk of gastrointestinal adverse effects and bleeding are available.

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12
Q

What is the MOST common adverse effect of non-selective NSAIDs?

A

Nausea and other gastrointestinal adverse effects

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13
Q

What is the normal function of prostaglandins in the stomach?

A

Protective effects:

(1) Increase bicarbonate secretion
(2) Increase mucus secretion
(3) Increase blood flow to mucosa
(4) Decrease acid secretion

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14
Q

Why do NSAID-induced pseudoallergic reactions occur?

A

Inhibition of cyclo-oxygenase (COX) causes shunting of arachidonic acid to overflow into the 5-lipoxygenase pathway for the production of leukotrienes. Leukotrienes activate cysteinyl leukotriene receptors promoting mast cell degranulation and allergic responses.

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15
Q

List common natural sources of salicylates that may be found in traditional or alternative medicines and supplements.

A
White willow (Salix alba) bark
Meadowsweet (Filipendula spp. formerly Spirea spp.)
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16
Q

What is the common chemical name of aspirin?

A

Acetylsalicylic acid

17
Q

At analgesic doses, what do ALL NSAIDs have in common?

A

At analgesic doses, all NSAIDs inhibit cyclo-oxygenase-2 (COX-2)

18
Q

For what severity of pain are NSAIDs useful as analgesics?

A

NSAIDs are only useful for analgesics for mild to moderate pain. NSAIDs have an analgesic ceiling as they work as analgesics by preventing prostaglandin-mediated sensitisation of nociceptive fibres.

19
Q

Explain why diclofenac is useful for the management of joint pain and inflammation.

A

Diclofenac accumulates in synovial fluid enabling a prolonged analgesic and anti-inflammatory at the joints while it has a relatively short plasma half-life and so fewer gastrointestinal adverse effects than other non-selective COX inhibitors.

20
Q

Name an NSAID that is an irreversible inhibitor of cyclo-oxygenase (COX).

A

Aspirin

21
Q

Which drug would be preferred for closure of patent ductus arteriosus in a premature infant?

A

Indometacin or ibuprofen are typically used for this purpose. These are older NSAIDs and so there is a historical precedent for use in infants and an accumulated knowledge of relative safety. Newer NSAIDs are unlikely to be used as there is less knowledge of their safety in infants.

22
Q

Why are ALL NSAIDs contraindicated in late pregnancy?

A

All NSAIDs inhibit cyclo-oxygenase-2 (COX-2) at analgesic and anti-inflammatory doses. Inhibition of COX-2 risks premature closure of the ductus arteriosus. All NSAIDs are therefore contraindicated in the third trimester.

23
Q

Which form of cyclo-oxygenase (COX) do platelets predominantly express?

A

Platelets express cyclo-oxygenase-1 (COX-1) which makes thromboxane-2 (TXA-2)

24
Q

In general, COX-1 is constitutive and COX-2 is inducible but EXCEPTIONS include…

A

Expression of COX-2 in the kidney, synovial joints, CNS and female reproductive system.

25
Q

The renal adverse effects of NSAIDs are due to inhibition of…

A

Both COX-1 and COX-2

26
Q

List at least THREE renal adverse effects of NSAIDs?

A

Increased sodium retention, water retention following sodium retention, risk of hyperkalaemia, and changes in renal blood flow dynamics.

27
Q

Aspirin is a more potent antiplatelet agent than other nonselective NSAIDs because it is…

A

An irreversible COX inhibitor

28
Q

Exposure to salicylates during viral infection is associated with increased risk of…

A

Reye’s syndrome

29
Q

Which NSAIDs would be most strongly contraindicated in a 10-year-old child with a viral infection?

A

Aspirin and other salicylates. Exposure to salicylates during viral infection are associated with increased risk of Reye’s syndrome.

30
Q

An elderly patient presents with bruising after taking an NSAID. The drug was most likely…

A

Aspirin

31
Q

List at least FOUR NSAIDs ranked from most strongly antiplatelet to most strongly prothrombotic.

A

Aspirin > Ketoprofen > Piroxicam > Indometacin > Naproxen > Ibuprofen > Diclofenac > Mefenamic acid > Celecoxib > Parecoxib > Etoricoxib

32
Q

Alcohol increases the hepatoxicity of paracetamol by altering its metabolism through…

A

Inducing minor pathway enzymes resulting in toxic metabolites and depleting glutathione, which is required to detoxify the toxic metabolites to nontoxic metabolites

33
Q

Hepatoxicity of paracetamol (acetaminophen) overdose can be treated with…

A

N-acetyl-cysteine helps to treat paracetamol toxicity by replenishing glutathione, which detoxifies the toxic metabolites of paracetamol to nontoxic metabolites

34
Q

The coxibs are markedly safer than non-selective NSAIDs for patients…

A

At risk of stomach ulcers

35
Q

List at least THREE adverse effects of COX-1 inhibition

A

Increased risk of nausea and vomiting, gastro-oesophageal reflux, stomach ulcers, bruising/bleeding, renal adverse effects contributing to hypertension and fluid retention. (Note that COX-2 inhibition also contributes to renal adverse effects).