Anti-HTN drugs Flashcards
HTN does what
Hypertension increases the risk of coronary thrombosis, stroke and renal failure
Controlling hypertension, which is generally asymptomatic, greatly improves prognosis
Blood pressure is an excellent surrogate marker for cardiovascular (CV) risk
Antihypertensive drugs prolong life and reduce CV risk
Examples of anti-hypertensive drugs
● Drugs targeting the renin-angiotensin-
aldosterone system (RAAS)
● Calcium channel blockers (CCBs)
● Diuretics
● Hydralazine
● Drugs targeting the sympathetic nervous
system
● Nitrates
Treatment strategy
-> A/CD rule
Angiotensin/ CCBs, Diuretics
-Thiazide diuretics and thiazide-like drugs
-Angiotensin Converting Enzyme Inhibitors (ACEIs) or
Angiotensin Receptor Blockers (ARBs)
-Long-acting Dihydropyridine Calcium Channel Blockers (CCBs)
BP formula
Blood Pressure=
Cardiac Output (CO) [Stroke vol. x HR] X Total Peripheral Resistance (TPR) [big determinant: blood vessel radius]
Decrease BP:
Decrease TPR
Decrease CO
Decrease body fluid volume
ANGIOTENSIN CONVERTING ENZYME INHIBITORS (ACEIs) Examples
enalapril, lisinopril, ramipril
ACEIs mechanism of axn:
-Affect arteries and veins:
Reduce cardiac load and arterial pressure
-No effect on cardiac contractility
-Increased CO
ACEIs
CLINICAL USES/ indications
● Hypertension
● Heart failure (HF)
● Post-MI
● High risk of ischemic heart disease
● Diabetic nephropathy
● Chronic renal insufficiency to prevent
progression
ADVERSE EFFECTS
Of ACEIs
● Hypotension:
Especially after first dose and
In heart failure treated with loop diuretics, where RAAS is highly activated
● Dry cough (bradykinin accumulation)
Avoid in asthma to avoid confusion between drug- vs. asthma-related cough
● Hyperkalemia: drug-drug interactions
● Angioedema (potentially via bradykinin)
● Renal failure in renal artery stenosis
- Contraindication in renal artery stenosis and acute kidney injury
-Glomerular filtration maintained by ATII- mediated vasoconstriction (efferent arterioles)
-Hyperkalaemia may be severe due to reduced aldosterone secretion
-Reversible if caught early and ACEIs discontinued
ANGIOTENSIN RECEPTOR BLOCKERS (ARBs)
Examples
-losartan, valsartan
ARBs MoA
•Behave similarly to ACEIs in clinical practice
-Similar effectiveness on BP reduction and CV
outcomes
Similar side effect profile
Minus the cough
ACEIs and ARBs are contraindicated in pregnancy
ACEIs and ARBs
Contraindications
pregnancy
Low renin populations
●Elderly
●Afro-Caribbean descent
CLINICAL USES
Of ARBs
•HTN especially in:
- young pts (have higher renin)
-Diabetic pts
- HTN complicated by LV hypertrophy
• Heart failure
•Diabetic neuropathy
. RENIN INHIBITORS
Example
. aliskiren
‘RENIN INHIBITORS
MoA
Lowers blood pressure but
Clinically somewhat unsuccessful
Only used if it’s options don’t work