15b - Diuretics + Cholesterol synthesis

Question 1

1) Describe, briefly, the renin-angiotensin aldosterone (RAAS) system.
2) Drug targets?

Answer 1

1) Drops in Na+ or Cl-, detected by kidneys which will retain Na+ and Cl- and H2O
- Liver releases angiotensionogen
- angiotensin 1 –(ACE)–> angiotensin 2
- SIts on AT1 receptor for vasoconstriction and increase aldosterone (which increases retention). Both of which increase BP.
2)
- AT1 receptor blockers and ACE inhibitors to lower BP.

Question 2

Name the drugs involved in the RAAS system

Answer 2

Captopril and Iosartan
ends in “-pril” and “-artan”

Question 3

What diuretics target the loop of Henle? Describe their mechanism.

Answer 3

Loop diuretics work by blocking the Na+/K+/2Cl- symporter (C1). This prevents reabsorption.

Question 4

What is the other diuretic that doesn’t target the loop of Henle? Mechanism?

Answer 4

Thiazide diuretics. Blocks Na+/Cl- co-transporter (C1) so reduced reabsorption.

Question 5

Compare loop diuretics from thiazide

Answer 5

Loop diuretics are stronger due to higher effect at higher dose. Thiazides plataeus at higher doses.

Question 6

Describe the transport of lipids in the body.

Answer 6

Chylomicrons and VLDL deliver triglycerides to cells.
VLDL or HDL -> LDL.
LDL is bad as they take cholesterol to cells and liver if excess
HDL is good because they break down LDL and take cholesterol from cells to liver.

Question 7

What are two antihyperlipidaemic drugs?

Answer 7

• HMG-CoA reductase inhibitors (statisn)
• Fibrates

Question 8

Ocular side effects of statins and BP medication?

Answer 8

Statins
- Exagerbate dry eye?
BP medication
- Diuretics + Ca2+ blockers = Glaucoma (should switch to ACE-I)
- Diuretics + beta-blockers = Dry eye…
- ACE-I = Decreased vision, photophobia…