Hypertensive drug (B17-B19) Flashcards
Classification of anti-hypertensive drug
Mechanisms of action of anti-hypertensive drugs
Classification of Hypertension
Class of anti-hypertensive drugs
- Diuretics( B23-24)
- Ca+ channel blockers (B18)
- Drugs acting on the sympathetic system
- Drugs acting on RAAS (B19)
- Vasodilators (B18)
Regulation of Blood pressure
Regulation of Vascular tone
Organic diseases developing as
consequences of HY
Main goals of anti-hypertension therapy
- Decrase mortality
- Inrease life span
- Better quality of life
- Decrease occurence of organ failure
* decreasing BP is not mail goal
The renin-angiotensin II-aldosterone system (RAAS) (B19)
- Various receptor blockers, Enzyme inhibition againt Angiotensinogen
- Renin inhibition
- ACE inhibition
- AT1 receptor blockers
Adverse events , problems or
limitations of RAAS antagonists
Adverse events
Dry cough ACE inhibitors
Hyperkalaemia - all of them
Angioneurotic oedema ACE inhibitors
Acute renal failure
Hypotension mostly when combined with diuretics
Limitations
Pregnancy !!! all of them are teratonegic
Bilateral renal artery or aorta stenosis
Afroamerican people low renin level , no effect
4 ACE inhibitors
enalapril (B19), perindopril(B19), ramipril(B19)
Mode of action, pharmacokinetics
enalapril (B19), perindopril(B19), ramipril(B19), Captopril (B19)
- enalapril (B19) :Enalapril 1x 5-20mg
- perindopril(B19)
- ramipril(B19)
- Captopril (B19) not prodrug
MOA : Inhibition of ACE:
- Decreasing Angiotensin II
• Decreasing peripheral vascular resistance ->
Decreasing BP (w/out affecting CO, HR, contractility)
• Decreasing Aldosterone -> Decreasing Na+ and H2O
retention -> Decreasing pre- and afterload -> Decreasing cardiac work
- Increasing bradykinin -> increasing NO and PGI2
• inceasing vasodilation (arteries and veins)
Pharmacokinetics
- kidney effects
- no affect glomerular filtration and creatinine clearance
- cause a mild glomerular vasodilatation
- a favorable effect on diabetic nephropathy
- Decrease the selective albumin clearance - Endocrine effects
- slightly increase the plasma renin level
- slightly decrease the plasma norepinephrine level
- Lipd and gluce metabolisms are not affected
3 Angiotensin II receptor blockers (ARBs)
Losartan(B19), Valsartan(B19), Irbesartan(B19)
Mode of action, Pharmacokinetics
Losartan(B19), Valsartan(B19), Irbesartan(B19)
- Losartan(B19)
- Valsartan(B19)
- Irbesartan(B19)
Inhibition of angiotensin II receptor (AT1):
- Similar effects to ACEI:
• Arteriolar and venous dilation and block of aldosterone secretion
-> decreasing BP and decreasing Na+ + H2O retention.
- These drugs are alternatives to ACEI in patients with severe coughs or
angioedema.
Telmisartan is the on ARB with PPARg activity (metabolic syndrome ttt?)
Dose: Valsartan 1x 80-320mg (hypertension)
1 Renin antagonist:
Aliskiren (not in the list)
About Aliskiren (not in the list)
1. Action:
- Directly inhibits the RAAS system in the early pathway
2. Pharmacokinetics:
- Administration:
o Oral, 1x/day
- Both in the absorption and biliary excretion, the P-glycoprotein is involved
- Elimination without inactivation (mainly)
3. Drug interactions:
- P-glycoprotein inductors (e.g. rifampicin) decrease the bioavailability
- P-glycoprotein inhibitors (e.g. ketoconazole, verapamil) enhance the plasma level
4. Contraindications:
- Combination with ACEIs or ARBs in diabetes and kidney insufficiency
