Pharmacology: NSAIDs Effects on Gestation and Labour

How do NSAIDs affect uterine contractility?

Inhibition of PG formation by NSAIDs decreases uterine contractility.

Why should NSAIDs not be administered before 34 weeks of gestation?

NSAIDs can result in the closure of the ductus arteriosus in newborns.

How do NSAIDs help in reducing primary dysmenorrhea?

NSAIDs reduce the production of prostaglandins by the uterus.

What is the function of the ductus arteriosus in a developing fetus?

It allows most of the blood from the right ventricle to bypass the fluid-filled nonfunctioning lungs. Signup and view all the answers

What is the common adverse effect of NSAIDs related to the gastrointestinal system?

Direct damage to gastric and intestinal mucosa. Signup and view all the answers

Which NSAID is known to cause acute ulcers by ion trapping to endothelium in the lumen?

Aspirin Signup and view all the answers

What is the primary physiological function of prostaglandins in the stomach?

The physiological function of mucosal prostaglandins in the stomach is cytoprotective, involving increasing mucous and bicarbonate secretion, decreasing acid secretion, increasing blood flow of the mucosa, and increasing the capacity for repairing damaged epithelium. Signup and view all the answers

How do selective COX-2 inhibitors differ from non-selective NSAIDs in terms of gastrointestinal adverse effects?

Selective COX-2 inhibitors have fewer gastrointestinal adverse effects than non-selective NSAIDs because COX-1 is responsible for the physiological protection function of the gastric mucosa. Signup and view all the answers

What is the mechanism by which NSAIDs can lead to hypertension?

NSAIDs can lead to hypertension by inhibiting the synthesis of vasodilator renal prostaglandins, which results in vasoconstriction and decreased renal blood flow, stimulating the renin-angiotensin-aldosterone system and leading to sodium and water retention. Signup and view all the answers

What is the difference in the gastric mucosal protection mechanisms between COX-1 and COX-2 enzymes?

COX-1 is responsible for the physiological protection function of the gastric mucosa, while COX-2 is not involved in this protective mechanism. This explains why selective COX-2 inhibitors have fewer gastrointestinal adverse effects compared to non-selective NSAIDs that inhibit both COX-1 and COX-2. Signup and view all the answers

How do prostaglandins regulate gastric acid secretion?

Prostaglandins decrease gastric acid secretion as part of their cytoprotective function in the stomach. Signup and view all the answers

What is the relationship between the inhibition of prostaglandin synthesis and the development of peptic ulcers?

Reduction of prostaglandin synthesis leads to a reduction in the protective measures of the gastric mucosa, resulting in damage to the mucosa and the development of gastrointestinal upset, erosions, and peptic ulcers. Signup and view all the answers

Describe the pathway of prostaglandin formation from arachidonic acid.

Arachidonic acid (AA) is stored in the cell membrane phospholipids. It is mobilized by the enzyme phospholipase A2. The released AA then undergoes metabolism by the cyclo-oxygenase (COX) enzyme pathway, which converts it into prostaglandins, prostacyclin, and thromboxane - collectively known as prostanoids. Signup and view all the answers

How do non-steroidal anti-inflammatory drugs (NSAIDs) affect the COX enzyme pathway?

NSAIDs inhibit the COX enzymes, particularly COX-2, which reduces the production of prostaglandins and other inflammatory mediators. This helps reduce inflammation, pain, and fever, but can also lead to side effects like gastric ulcers due to the inhibition of the protective COX-1 enzyme. Signup and view all the answers

What are the three main types of COX enzymes and how do they differ in their functions?

The three main types of COX enzymes are COX-1, COX-2, and COX-3. COX-1 is a constitutive enzyme involved in normal physiological functions like maintaining the gastric mucosal lining and regulating renal blood flow. COX-2 is an inducible enzyme that is upregulated during inflammation and plays a role in the inflammatory response. COX-3 is a variant of COX-1 and its exact function is not fully understood, but it may be involved in pain and fever pathways. Signup and view all the answers

What is the role of prostaglandins in the inflammatory response?

Prostaglandins are lipid mediators that are produced during the inflammatory response. They contribute to the cardinal signs of inflammation, such as redness, swelling, pain, and fever. Prostaglandins also play a role in regulating blood flow, platelet aggregation, and other physiological processes. Signup and view all the answers

Explain the difference between the 1st and 2nd pathways of arachidonic acid metabolism.

The 1st pathway of arachidonic acid (AA) metabolism involves the cyclo-oxygenase (COX) enzymes, which convert AA into prostaglandins, prostacyclin, and thromboxane. The 2nd pathway involves the lipoxygenase (LOX) enzymes, which convert AA into leukotrienes and lipoxins. These two pathways produce different classes of lipid mediators that have distinct roles in the inflammatory response. Signup and view all the answers

Explain the role of phospholipase A2 in the arachidonic acid pathway.

Phospholipase A2 is the enzyme responsible for mobilizing arachidonic acid (AA) from the cell membrane phospholipids. Once released, the AA can then undergo metabolism by the COX and LOX enzyme pathways to produce various lipid mediators like prostaglandins, leukotrienes, and lipoxins that are involved in the inflammatory response. Signup and view all the answers

Pharmacology: NSAIDs Effects on Gestation and Labour

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