Antihypertensives Flashcards
(21 cards)
How do calcium channel blockers (e.g. Nifedipine) work?
They reduce the force of contraction of the heart. Calcium is needed for cardiac muscle to contract, these drugs block the channels that bring calcium into heart cells.
What does Captopril block the formation of?
Angiotensin II. Captopril blocks ACE in the lungs which prevents the formation of Angiotensin II.
Which organ is not a target for anti-hypertensive drugs?
Liver.
Blood pressure=?
Cardiac output x total peripheral resistance.
What determines cardiac output?
Venous tone, blood volume, heart rate & volume of blood pumped out.
What are the targets for antihypertensive drugs?
Kidneys, Brain, Blood Vessels & Heart.
Name the ABCD’s of antihypertensive drugs.
A = ACE inhibitors B = Beta blockers C = Calcium channel blockers D = Diuretics
What do ACE inhibitors do?
Block ACE ➡️ Vasodilation
Reduce peripheral resistance
What drugs are ACE inhibitors?
Captopril, Enalapril, Trandopril, Ramipril & Lisinopril.
What are the side effects of ACE inhibitors?
Persistent dry cough, rash, renal problems, hypotension.
What system do beta blockers act on?
Sympathetic nervous system.
What are the actions of beta blockers?
Reduce HR, Block vasoconstriction, Increase blood flow to kidneys ➡️ reduce renin secretion.
Which drugs are beta blockers?
Atenolol, Bisoprolol, Metoprolol, Propranolol & Sotalol.
What are the side effects of beta blockers?
Lethargy, impaired concentration/memory, aching limbs during exercise, erectile dysfunction, poor blood supply to peripheries & aggravation of asthma.
When are alpha-blockers used?
In severe cases of hypertension.
What do alpha-blockers do?
They block the action of NAdr and adrenaline on blood vessels ➡️ vasodilation.
Which drugs are alpha-blockers?
Prazosin - short acting.
Doxazosin & Terazosin - longer acting.
What do calcium channel blockers do?
Can dilate arteries
Reduce heart contractility and/or reduce HR
Which drugs are calcium channel blockers?
Nifedipine, Amlodipine & Nicardipine.
These are more potent on blood vessels than the heart and may cause headaches, dizziness, flushing, peripheral oedema.
Verapamil & Diltiazem
These are more potent on the heart than blood vessels and may cause constipation, heart block and cardiac failure.
Which type of diuretics are useful for treating severe hypertension?
Loop diuretics such as furosemide.
What is a vasodilator?
A drug that causes relaxation of smooth muscle cells in blood vessels allowing blood to flow easier.
