Hypertension Barker Exam 3 Flashcards
What pulse pressure threshold is a very important indicator for CV risk?
> 65mmHg
Blood pressure = __ x __
CO x PVR
Which blood vessels do organic nitrates affect more–veins or arteries?
Veins
What two classes of drugs block compensatory responses like tachycardia and Na/H2O retention?
Diuretics (block kidney compensation) and beta blockers (block both kidney and heart compensation)
How does a catecholamine depleter like reserpine work?
Blocks monoamine transport into vesicles for release–depletes pool of NE in vesicles. Slow onset and terrible SE, but minimal compensatory response.
How do a2 agonists like clonidine, methyldopa, guanabenz, and guanfacine work to reduce BP?
They act at a central a2 GPCR (and some other imidazoline receptor?) to stimulate Gi, decreasing cAMP and causing hyperpolarization–leads to less sympathetic output (decrease HR, decrease contractility, decrease renin release, vasodilation–decrease CO and PVR both).
Rank the half lives of clonidine, guanabenz, and guanfacine from shortest to longest.
Guanabenz, guanfacine, clonidine
What side effects are common with a2 agonists?
Dry mouth, sedation, depression, withdrawal syndrome, Na+/H2O retention. (lactation + positive coombs test for hemolytic anemia with methyldopa as well).
Rank the half lives of the a1 antagonists from shortest to longest acting.
Prazosin, terazosin, doxazosin
What is the main mechanism of action of a1 antagonists?
Dilate both arteries (decrease PVR) and veins (decrease CO). More often for BPH.
What side effects are associated with the -zosins?
First-dose orthostatic hypotension, Na/H2O retention, slight tachycardia.
What was the first beta blocker, and as such has less preferrable properties such as non-selectivity, high lipophilicity, and higher side effects?
Propranolol (Inderal)
Side effects include negative lipid impact, inhibited hypoglycemia reaction, and bronchial airway resistance.
What cardioselective beta blocker must be given multiple times per day or as an extended release formulation due to its short half life?
Metoprolol tartrate
What cardioselective beta blocker may be given once a day due to its longer half life?
Atenolol–its a 10!
Metoprolol help to slow progression in early stages of this disease, but contraindicated in later stages of this disease. What disease?
Congestive heart failure–blocks renin-induced damage
What is the main mechanism of beta-blocker activity?
They block beta-1 induced release of renin from the kidney.
What beta blocker works through producing NO in addition to the normal beta blocker actions?
Nebivolol (Bystolic)
What are the general side effects of beta blockers? Contraindications?
SE: Bradycardia, AV block, sedation, withdrawal, mask hypoglycemia.
CI: Asthma, COPD, CHF type IV
What beta blocker has the additional activity of a1 antagonism (mixed adrenergic antagonist), may be given parenterally, and has only one isomer that posesses a1 blocking activity?
Labetalol (Trandate)
What mixed adrenergic antagonist can block a1 receptors with either enantiomer?
Carvediolol (Coreg)
Why should labetalol and carvediolol never be given to a patient with COPD or asthma?
Because both have nonselective B blocking activity.
What general feature of diuretics leads to potassium loss?
Increased sodium delivery to the collecting tubule–K+ and Na+ are exchanged.