Lecture 37 - Adverse Drug Effects Flashcards
Why is the kidney easy to kill?
Great oxygen requirement
(AT: Reabsorption and secretion)
However, oxygen delivery to the Loop of Henle can be marginal due to countercurrent flow
When is Na transport passive?
Out of lumen into proximal tubule cells
When is Na+ transport active?
Pumping out of tubule cell into the vasa recta
What are the requirements of the kidney?
Great oxygen requirement
due to active transport
Describe conventional oxygen delivery
Delivered by artery to capillary
Vein brings back deoxygenated blood
What is special about the renal and testicular vasculature?
Countercurrent exchange of oxygen
From arterioles to venules in adjacent nephrons
What conditions can lead to renal damage?
Low renal perfusion
- dehydration
- drugs (Triple whammy)
Not enough blood flow to the nephrons, not enough oxygen delivered
What is the triple whammy?
Diuretic
ACE inhibitor
NSAID
–> acute renal failure
Why does acute renal failure occur from a triple whammy?
NSAIDs block prostaglandin synthesis
Prostaglandin vasodilation required for renal blood flow
Why do triple whammies occur?
Patients self persribe NSAIDs such as aspirin
Are drug-drug interactions direct or indirect?
Both
Describe oxygen delivery in the nephron
The venule side of the vasa recta of a single nephron overlies the arteriole side of the adjacent nephron. In this way, oxygen from the arterioles are delivered to the venules.
What is the outcome of counter-current blood flow in the nephrons?
Talk about an implication of this
Relative hypoxia in the medulla of the kidney.
–> The oxygen takes a ‘short cut’, and thus remains in the cortex
The loop of Henle has a high oxygen requirement, as it is undergoing much active transport.
Thus, the nephron is at risk if oxygen delivery drops even slightly
What is the function of a diuretic?
Lowers blood volume
What is the function of an ACE inhibitor?
Prevents formation of Angiotensin II
