GORD

Question 1

NSAIDs full form and examples

Answer 1

Non-steroidal anti-inflammatory drugs, eg. ibuprofen, diclofenac, naproxen

Question 2

NSAIDs prim mech

Answer 2

inhibit COX enzyme, limits production of prostanoids from arachidonic acid (prostanoids are prostaglandins and thromboxanes so limiting production stops inflammation)

believe that anti-inflammatory, analgesic and anti-inflammatory actions of NSAIDs are mostly due to COX-2 inhibition whereas unwanted side effects more due to COX1

Question 3

NSAIDs drug target

Answer 3

COX enzyme

Question 4

NSAIDs side effects

Answer 4

Common unwanted effects include gastric irritation, ulceration and bleeding and, in extreme cases, perforation; reduced creatinine clearance and possible nephritis; and bronchoconstriction in susceptible individuals (contraindicated in asthma). Skin rashes & other allergies, dizziness, tinnitus.
Adverse cardiovascular effects (hypertension, stroke, MI) may occur following prolonged use or in patients with pre-existing CV risk.
Prolonged analgesic abuse over a period of years is associated with chronic renal failure.
Aspirin has been linked with a rare but serious post-viral encephalitis (Reye’s syndrome) in children.

Question 5

PPI full form and examples

Answer 5

Proton pump inhibitors: lansoprazole, omeprazole, rabiprazole and esomeprazole

Question 6

PPI prim mech

Answer 6

Irreversible inhibitors of H+/K+ ATPase in gastric parietal cells. They are weak bases and accumulate in the acid environment of the canaliculi of the parietal cells. This concentrates their actions there and prolongs their duration of action
(omeprazole plasma half-life approx. 1 h but single daily dose affects acid secretion for 2-3 days). Proton pump inhibitors inhibit basal and stimulated gastric acid secretion by >90%.

Question 7

PPI drug target

Answer 7

H+/K+ ATPase

Question 8

PPI side effects

Answer 8

Unwanted effects are uncommon but may include headache, diarrhoea, bloating, abdominal pain & rashes.
The use of these drugs may mask the symptoms of gastric cancer.
Omeprazole is an inhibitor of cytochrome P2C19 and has been reported to reduce the activity of e.g. clopidogrel, when platelet function is monitored.

Question 9

H2 Receptor antagonist example

Answer 9

ranitaidine

Question 10

H2 receptor antagonist prim mech

Answer 10

H2 antagonists are competitive antagonists of H2 histamine receptors (structural analogues of histamine). They inhibit the stimulatory action of histamine released from enterochromaffin-like (ECL) cells on the gastric parietal cells. They inhibit gastric acid secretion by approximately 60%.

Question 11

Ranitidine drug target

Answer 11

Histamine H2 receptor

Question 12

H2 receptor side effects

Answer 12

Incidence of side-effects is low. Diarrhoea, dizziness, muscle pains & transient rashes have been reported.
Cimetidine (but not other H2 antagonists) inhibits cytochrome P450 and may retard the metabolism and potentiate the effects of a range of drugs incl. oral anticoagulants and TCAs.

Question 13

Paracetamol other name

Answer 13

acetaminophen

Question 14

acetaminophen prim mech

Answer 14

Its actions appear to be largely restricted to nervous tissue but its mechanism of action is unclear. Current hypotheses suggest both a central and peripheral action possibly involving interaction with a COX-3 isoform (inhibition of PG synthesis), cannabinoid receptors or the endogenous opioids. Interactions at 5HT & adenosine receptors have also been proposed.


Question 15

Paracetamol drug target

Answer 15

Not sure but think its a COX3 isoform

Question 16

Paracetamol side effects

Answer 16

Generally a very safe drug with few side-effects at therapeutic doses. It does not cause gastric irritation but in overdose serious hepatotoxicity may occur. Occasional allergic skin reactions.