blood pressure drugs Flashcards
(37 cards)
what is defined as clinical hypertension?
clinic blood pressure 140/90 mmHg (other definitions are considered depending on method of blood pressure measurement or in those who are frail or multi-morbid)
what are therapeutic options for hypertension?
→angiotensin converting enzyme inhibitors (ACE)
→angiotensin II receptor blocker
→calcium channel blocker
→thiazide like diuretic
normally what happens with RAAS (renin-angiotensin-aldosterone system)?
starts with kidney detecting drop in blood pressure or reduced flow → renin being produced in kidney →through bloodstream & goes to liver where acts on plasma protein angiotensinogen to convert renin to angiotensin I →travels to lungs angiotensin converting enzyme (ACE) converts to angiotensin II which leads to:
- thirst and AVP secretion (makes you drink more fluid - AVP reduces water loss by kidneys)
- aldosterone secretion (promotes reabsorption of Na+ and water by kidneys)
- renal haemodynamics →increase circulating blood volume and increase blood pressure
what does ACE inhibitor do?
angiotensin converting enzyme (ACE) inhibitors prevent angiotensin I →angiotensin II therefore reduces all the effects of angiotensin II and means decreased circulating blood volume and decreased blood pressure
what is an example of ACE inhibitor drug?
perindopril
→Inhibits the action of angiotensin converting enzyme (ACE)
→Important in the treatment of hypertension AND heart failure
what is effects of angiotensin II?
- Angiotensin II acts on the kidneys to increase Na+ and water reabsorption (by thirst and AVP secretion and aldosterone secretion)
- Angiotensin II is also a vasoconstrictor
what is the first line of treatment in hypertension with type 2 diabetes?
- ACE inhibitors
- angiotensin II receptor blocker
what is side effect of ACE inhibitor?
dry cough (excess bradykinin)
what are some effects of the ACE inhibitor?
- Very valuable in treatment of heart failure (Chronic failure of the heart to provide sufficient output to meet the body’s requirements – can lead to both peripheral and pulmonary oedema)
- ACEi → decrease vasomotor tone (↓blood pressure)
- Reduce afterload of the heart
- ALSO Decrease fluid retention (↓blood volume)
- Reduce preload of the heart (volume blood return to ventricles)
- BOTH effects reduce work load of the heart
what is alternative to ACE inhibitor? (as some people can’t tolerate ACEi)
angiotensin II receptor blocker
what is an example of angiotensin II receptor blocker?
losartan
= used in treatment of heart failure & hypertension
what is effect of angiotensin II receptor blocker?
decreased veno/arterioconstriction and so decreased blood pressure
what is an example of a loop diuretic?
furosemide
= reduces pulmonary and peripheral oedema
- used to treat conditions where excessive fluid retention or edema is a concern
what are diuretics used to treat?
used in treatment of heart failure & hypertension
what are some examples of calcium channel blockers?
Amlodipine, nicardipine
what do calcium channel blockers do?
- stop smooth muscle cells from contracting so decrease arterial blood pressure
- Decrease peripheral resistance
- Decrease arterial BP
- Reduce workload of the heart by reducing afterload
when are calcium channel blockers used?
useful in hypertension, angina, coronary artery spasm, supraventricular tachycardias
what is an example of a calcium channel blocker that isn’t effective in preventing arrhythmias but can act on vascular smooth muscle?
Dihydropyridine Ca2+ channel blockers
what drugs do you use if main therapeutic treatments for hypertension don’t work?
antihypertensive drugs:
- Vasodilator antihypertensives
- Centrally acting antihypertensives
- Adrenergic neurone blocking drugs
- Alpha adrenoreceptor blocking drugs
what are vasodilators antihypertensives?
= potent hypotensives (especially when they are given in combination with beta blocker and a thiazide diuretic)
- used for resistant hypertension (when other drugs don’t work)
what are examples of Vasodilator antihypertensives?
Hydralazine and minoxidil
what are centrally acting hypertensives and examples?
- used for resistant hypertension (when other drugs don’t work)
= Methyldopa and clonidine (usually very far down the line)
what are Alpha adrenoreceptor blocker drugs and examples?
- used for resistant hypertension (when other drugs don’t work)
Prazosin and terazosin (usually very far down the line)
what are positive inotropes drugs and examples?
= increase contractility & thus cardiac output
cardiac glycosides →example = digoxin
beta adrenergic agonist →example = dobutamine