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Flashcards in NSAIDS & Paracetamol Deck (14)
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0

What are NSAIDS?

"Non steroidal anti-inflammatory drugs" - they are used generally to treat mild to moderate somatic pain classically. They also inhibit COX1&2 (cyclooxygenase) which in turn decreases the conversion of Arachidonic acid into PGG2

1

What is an opioids used to treat?

Moderate to severe visceral and somatic pain

2

If COX is not inhibited by a NSAID what are the normal physiological functions of PGF2? And state any relevant contraindications in using a NSAID.
(PG=Prostaglandins)

- Uterine contraction
Can't use a NSAID in pregnancy as it will stop uterine contractions; however, it could be applicable if the baby is predicted to be premature as it will slow contractions and keep the baby inside the mother longer.

3

If COX is not inhibited by a NSAID what are the normal physiological functions of PGE2? And state any relevant contraindications.
(PG=Prostaglandins)

Vasodilation and Gastric cytoprotection

4

If COX is not inhibited by a NSAID what are the normal physiological functions of PGI2? And state any relevant contraindications.
(PG=Prostaglandins)

Vasodilation and Gastric cytoprotection and decreases platelet aggregation (prostacyclin) by decreasing TXA2

5

If COX is not inhibited by a NSAID what are the normal physiological functions of TXA2? And state any relevant contraindications.
(TX= Thromboxane)

Platelet aggregation

6

Describe the mechanism of Coxibs.

They are the newer and less available version of a NSAID. They act on COX2 and inhibit its activity thus causing a decrease in prostaglandins production from inducible constitutive functions of inflammation and a decrease in inflammation.

7

Describe the mechanism of NSAIDS.

Act on COX1&2. COX1 - inhibits the homeostatic prostaglandins which decreases gastrofunction, renal function and platelet formation. COX2 - inhibits constitutive functions in inducible inflammation which decreases those prostaglandins and inflammation.

8

What does COX1 do?

- Housekeeping enzyme
- Synthesis of housekeeping prostaglandins
- Gastric cytoprotection
- Platelet thromboxane A2
- Uterine contraction
- GIT contraction
- Vasodilation

9

What does COX2 do?

- inducible enzyme
- induces (cytokines, growth factors and bacterial lipopolysaccharides)
- increases prostaglandins at sites of inflammation
- housekeeping function in synthesis of PGI2 and renal function

10

How does COX work?

- it's product is tissue dependent
- functions within the endoplasmic reticulum
- COX1 has a narrower channel (Coxibs block only COX2 while smaller NSAIDS block both 1&2)

11

List the adverse drug reactions of non-selective COX inhibitors and name an example of one.

Eg: Aspirin
Effects as a result of PG inhibition:
- GIT problems (lesions, bleeding, ulceration etc)
- *Prolonged bleeding time
- Renal vasoconstriction (nephrotoxicity)
- *Pregnancy (prolonged gestation/bleeding)
Effects not related to PG:
- *Hypersensitivity reactions (rash/bronchospasm)
- Tinnitus (severe ringing in the ear)
- Drug interactions (anticoagulants, anti hypertensives and lithium)

12

List the adverse drug reactions of selective COX2 inhibitors.

Effects related to PG inhibition:
- increased TXA2 by inhibiting PGI2
- renal Vasculature constriction (decreases GFR)
- *myocardial infarction & stroke

Note: 50% less chance of a serious adverse effect over a non-selective COX inhibitor

13

List 2 selective COX2 inhibitors (COXIBS) and name their areas of effect/treatment.

- Celecoxib (arthritis)
- Etoricoxib (musculoskeletal)