Cardio L26 Drug therapy 3 Flashcards
Angina definition
A condition marked by severe chest pain, often also spreading to the shoulders, arms and neck, caused by an inadequate blood supply to the heart.
Clinical definition of angina
Angina is chest pain or discomfort that occurs when an area of your heart muscle doesn’t get enough oxygen-rich blood.
Angina pectoris
Pain localized to the chest that can be abrupt (acute) or persistent (chromic)
Causes of angina pectoris
Decreasing o2 supply
Increase Cardiac work = o2 consumptions increased
→ Lack of supply and build up of metabolites leads to ischemic pain.
Common Causes of Angina Pectoris
- Restriction (usually incomplete) in blood supply to working heart muscle.
→ Partial occlusion of blood vessels Atheroma Thrombus →Vasopasm in coronary arteries Overly reactive vessels Drugs e.g. cocaine, smoking → Severe anaemia
Types pf angina pectoris
- Chromic stable angina (exercise induced)
- Unstable angina (sudden rupture of atherosclerotic plaque)
- Prinzmetals (angina inversa)
• Vasospasm due to oversensitivity to vasoconstrictors
Atheroma process
→Damage to endothelium
→ Cholesterol accumulation
→ Monocyte invasion
→ Foam cell degeneration
Foam cell degeneration
- Fibrous tissue, calcium salts
- Artery narrows
- Increasing stiffness at margin
Monocyte invasion
- Convert to macrophages
* Convert to foam cells
Cholesterol accumulation
- Oxidation
* Inflammatory response
Damage to endothelium
• Exposes intima matrix above smooth muscle layer
Prevent atherosclerosis
- Statins
- Fibrates
- Bile acid binding resins
Angina control
Nitrates
Beta-blockers
Ca2+ channel blockers
(Aspirin)
Treatment – possibly after first
MI
- Ranolazine, aspirin
2. Bypass surgery, stents, angioplasty, clot disrupting drugs (enzymes)
Process of cholesterol formation
3-Hydroxy-3- methyl-glutaryl-CoA reductase is the rate-controlling enzyme of the mevalonate pathway, which produces cholesterol and other isoprenoids.
Lovastin and Atorvastatin action
Inhibit 3-Hydroxy-3- methyl-glutaryl-CoA reductase leading to:
a. Decreased liver cholesterol synthesis
b. Increased VLDL and LDL receptor expression, and decreasing LDL in blood
Side effects: HMG CoA reductase inhibitors:
a. Myalgias
b. Muscle cramps
c. Rhabdomyolysis (leading to kidney failure)
d. GI tract disturbances
e. Malabsorption of lipid soluble vitamins (A,D,E,K) and lipid soluble drug
Fibrates: definition
Fibrates are amphiphatic carboxylic acids.
Fibrates: Example drugs
Bezafibrate
Ciprofibrate
Agonists of the peroxisome proliferator-activated receptor alpha (PPAR – alpha) receptor leads to:
- Increased Beta-pxidation in the liver
- Decreased hepatic triglyceride secretion
- Increased lipoprotein lipase activity → increased VLDL clearance
- Increased HDL
Main use of fibrates
Hypercholesterolemia
Side effects of fibrates
- Mild stomach upset and myopathy (muscle pain with CPK elevations)
- Increased risk for gallstones due to increased cholesterol in bile.
- Increased risk of rhabdomyolysis – especially if added to statins.