NSAIDs

Question 1

What is the main mechanism of NSAIDs

Answer 1

They all work by decreasing the activity of prostaglandins

Question 2

What is the synthesis of prostaglandin

Answer 2

Arachidonic acid is a precursors of Prostaglandins. And these are found in the phospholipids cell membrane. There are 2 pathways to synthesis them. Cox pathway and the lipoxygenase pathway

Question 3

Explain the Cox pathway

Answer 3

All eicosanoids with ring structure such as the prostaglandins, thromboxanes, and prostacyclins are synthesised in this pathway. They are 2 isomers called Cox1 and Cox2.

Co1 is important in the formation of prostanoids COX-1 enzyme that regulates normal cellular processes, such as digestive juice, it protects the lining of the stomach, vascular homeostasis, platelet aggregation, and reproductive and kidney functions.

whereas cyclooxygenase-2 (COX-2) causes the elevated production of prostanoids that occurs in sites of chronic disease and inflammation. This is induced by oxidative stress, injury, ischemia, seizures and neurodegenrative diseases. Glucocorticoids are in the pathways. COX 2 is found in the brain, kidneys and bones

COX-1 was found in blood vessels, interstitial cells, smooth muscle cells, platelets and mesothelial cells. In contrast, COX-2 was found predominantly in the parenchymal cells of many tissues, with few exceptions, for example the heart.

Question 4

What is the lipoxygenase pathway

Answer 4

So arachidonic acid found from membrane phospholipids is converted by 5-lipoxygenase into leukotrienes

Question 5

What is the function of Protaglandins

Answer 5

Prostaglandins have a major role in modulating pain, inflammation, and fever. They also control many physiological functions, such as acid secretion and mucus production in the gastrointestinal (GI) tract, uter- ine contractions, and renal blood flow. Prostaglandins are also among the chemical mediators that are released in allergic and inflammatory processes.

Question 6

What are the general side effects of NSAIDs

Answer 6

indigestion – including stomach aches, feeling sick and diarrhoea

stomach ulcers – these can cause internal bleeding and anaemia; extra medicine to protect your stomach may be prescribed to help reduce this risk

headaches
drowsiness
dizziness
allergic reactions (skin rash)

in rare cases, problems with your liver, kidneys or heart and circulation, such as heart failure, heart attacks and strokes

Question 7

List NSAIDS drugs

Answer 7

Acetaminophen (Paracetamol)- weak anti-inflammatory activity as it has less effect on cox in peripheral tissues. Acetaminophen does not affect platelet function or increase blood-clotting time. Acetaminophen is not considered to be an NSAID.. It rather inhibits prostaglandin synthesis in the CNS

Ketorolac is a non-selective COX inhibitor.

Metamizole inhibits both Cox1 and Cox2

Nefopam- inhibits histamine receptors NSAIDs used for post surgical pain