Hypertensive drugs Flashcards
What is the mechanism of action for angiotensin-converting enzyme (ACE) inhibitors?
- ACE inhibitors act by blocking the effect of ACE.
- ACE is important in the conversion of Angiotensin I to II.
- Thus blocking it causes a reduction in circulating angiotensin II.
Reduction of angiotensin II has numerous effects:
- Reduced aldosterone secretion - involved in volume regulation via sodium and potassium excretion.
- Reduced ADH secretion - anti-diuretic hormone (ADH) acts on the kidneys to increase water reabsorption (independent of sodium).
- Reduced arterial vasoconstriction
- Reduced sympathetic activity
A dry cough is the most common adverse effect of which drug class?
Angiotensin-converting enzyme (ACE) inhibitors
Why does Angiotensin-converting enzyme (ACE) inhibitors commonly cause a dry cough?
A dry cough is a common side effect of ACE inhibitors.
ACE inhibitors cause the break down of bradykinin and thus there is an increase in bradykinin within the lungs
Name a few adverse effects of angiotensin coverting enzyme inhibitors (ACE inhibitors)
- Dry cough
- Headache
- Postural hypotension
- Rashes
- Angio-oedema
- Strongly teratogenic
What is the mechanism of action for Dihydropyridine calcium channel blockers (CCB)?
Dihydropyridine CCBs block the action of voltage-gated L-type calcium channels, which are found in vascular and cardiac tissue.
Within vascular smooth muscle, L-type channels permit the entry of calcium ions leading to contraction and subsequent vasoconstriction.
Dihydropyridine CCBs inhibit this influx of calcium ions and induce vasodilatation, which reduces the peripheral vascular resistance.
Name the two main types of Calcium channel blockers (CCBs)?
Dihydropyridine: predominantly anti-hypertensive effects.
Non-dihydropyridine: predominantly anti-arrhythmic effects.
Dihydropyridine CCBs block the action of which calcium channel?
Voltage-gated L-type calcium channels
Name some of the adverse effects of calcium channel blockers (CCB)?
- Headache
- Flushing
- Dizziness
- Peripheral oedema
- Reduced cardiac contractility
- Constipation
Bendroflumethiazide is a part of which drug class?
Thiazide diuretics
Nifedipine is a part of which drug class?
Calcium channel blockers (CCBs)
Lisinopril is a part of which drug class?
Angiotensin-converting enzyme (ACE) inhibitors
Ramipril is a part of which drug class?
Angiotensin-converting enzyme (ACE) inhibitors
What is the mechanism of action of Thiazide-like diuretic?
Thiazide diuretics act on the distal convoluted tubule (DCT) of the nephron where it inhibits the Na+/Cl- co-transporter. This prevents sodium and chloride entering the tubule cells and, therefore, water cannot follow.
This mechanism has an initial hypotensive effect; however, this is mostly abolished by the renin-angiotensin system (RAS).
Instead, thiazide diuretics long-term antihypertensive effects are due to vasodilation of peripheral vasculature through a mechanism that is poorly understood.
Thiazide diuretics act on which part of the nephron?
Distal convoluted tubule (DCT)
Thiazide like diuretics act on which receptor in the nephrons?
Thiazide diuretics act to inhibit the Na+/Cl- co-transporter on the distal convoluted tubule (DCT) of the nephron