antihypertensive drugs Flashcards
What is the physiological control of blood pressure?
cardiac output
contractile state of resistance arterioles
volume
What controls the cardiac output?
heart rate (sympathetic) stroke volume - filling pressure and contractility (sympathetic)
What controls the contractile state?
neural (para + symp ns) hormonal (renin-angiotensin-aldosterone system) local transmitters (NO)
What controls the volume of blood pressure?
hormonal (RAS, ADH, ANP)
What are the antihypertensive drug strategies?
reduce cardiac output
dilate resistance vessels
reduce vascular volume
How can we reduce cardiac output?
β-adrenergic blockers: not 1st line
calcium channel blockers
How can we dilate resistance vessels?
calcium channel blockers
renin-angiotensin system blockers
α1 adrenoceptor blockers
nitrates**
How can we reduce vascular volume?
diuretics. RAS blockers
What organ does the angiotensin precursor come from?
liver
What does the angiotensin precursor become once in contact with renin?
angiotensin I
What converts angiotensin I to angiotensin II?
angiotensin converting enzyme
What does angiotensin II target?
AT1 receptor
What does a stimulation at the AT1 receptor cause?
vasoconstriction
What causes the release of renin?
aldosterone
decrease renal blood flow
increase sympathetic
What are some ACE inhibitors?
perinodpril
ramipril
anything ending in -pril
What are some angiotensin receptor blocker (ARB)?
candesartan
irbesartan
anything else ending in -sartan
How does the ANs regulate blood pressure?
effects on both pump output and resistance in the circulation
What is the autonomic baroreceptor reflexes in BP control?
- decrease BP
- carotid sinus senses
- vasomotor center respond (increase sns and decrease pns)
- increase PVR at α1 + increase heart rate + contractility at β1
= increase BP
What are some β1 adrenoceptor antagonists?
Metoprolol, atenolol, other -olol’s
What is an α1 adrenoceptor blocker?
Prazosin
What is the role of Prazosin?
relaxes peripheral resistance vessels
What occurs when calcium enters a muscle cell?
muscle contraction (myocardial or vascular) caused by the sarcoplasmic reticulum
What are the two types of calcium channel blockers?
cardioselective
vascular smooth muscle selective
What are the main roles of cardioselective calcium channel blockers?
reduce cardiac contractility
reduce automaticity
What are some cardioselective calciumi channel blocker drugs?
Verapamil
Diltiazem
What is the role of the vascular smooth muscle selective calcium channel blockers?
reduce vascular resistance
What are some examples of vascular smooth muscle selective calcium channel blocker drugs?
Dihydropyridines (nifedipine, felodipine, amlodipine)
Diltiazem
