Hyperlipidaemias Flashcards
What is the mechanism of action of statins?
- competitive inhibition of HMG-CoA reductase
- limits conversion of HMG-CoA to mevalonate > less cholesterol made
- up regulation of hepatic LDL receptors
- increased clearance of circulating LDL
What is cholesterol essential for?
- Membrane integrity
- Production of steroid horomones, bile acids + vitamin D
Types of lipoproteins
Chylomicrons
VLDL
IDL
LDL
HDL
Function of Chylomicron
Transports dietary TAGs from intestines to tissue
Function of VLDL
Transport liver synthesised TAGs to adipose tissue for storage
Function of IDLs
Transport liver synthesised cholesterol to tissues
Function of LDLs
Transport liver synthesised cholesterol to tissue
Function of HDLs
Transports excess tissue cholesterol to liver for disposal as bile salts
What are the uses of stains?
Hypercholesterolaemia
Prevention of cardiovascular disease
Reduce risk of atherosclerosis
What are the adverse effects of statins?
- GI disruption > nausea, constipation + diarrhoea
- headache
- diffuse muscle pain
- increased liver enzymes
- Rhabdomyolysis (rare)
What are contraindications of statins?
Renal or hepatic impairment
Pregnancy or breastfeeding
What are the important drug drug interactions of stains?
Amlodipine
Drugs which inhibit CYP3A4: amiodarone, Macrolides (e.g. clarithromycin)
What effects do statins have that contribute towards reduction in cardiovascular disease risk?
- reduce cholesterol
- improved vascular endothelial function
- stabilising of atherosclerotic plaques
- improved haemostasis
- anti-inflammatory + antioxidant
= reduction in cardiovascular disease risk
Examples of statins
Atorvastain
Rosuvastatin
Simvastatin
What is the suffix of stains?
-statin
Why may a simvastatin be suggested to be taken at night time?
- Most cholesterol is made at night
- Simvastatin has a short half life
- Can have the ‘best aciton’
Why shouldn’t you have grapefruit juice whilst taking statins?
Grapefruit inhibit CYP3A4 causes higher levels of stain in blood