Quiz 3 Study Guide: Antihypertensives Flashcards
What does a Diuretic do?
Depletes sodium
Reduces blood volume
Where do diuretics work?
In the Renal Tubule
What are examples of Diuretics?
Thiazides (hydrochlorthiazide)
Loop (furosemide)
Aldosterone (spironolactone and amiloride)
Osmotic (mannitol)
Carbonic anhydrase inhibitor (acetazolamine)
What are the drug categories of antihypertensives?
Diuretics Alter sympathetic tone Arteriole Dilators Calcium Channel Blockers Angiotensin affectors Ganglionic Blockers
Characteristics of Thiazide Diuretics (hydrochlorthiazide, chlorthalinidone)…
-First order drug
Causes:
- Electrolyte imbalances especially K+ (hypokalemia)
- Glucose intolerant
- inhibited by NSAIDS
Where do Thiazide Diuretics work?
Distal Convoluted Tubule
What are characteristics of Loop Diuretics (Furosemide, Bumetanide)
- Very Efficacious
- Reduce NaCl reabsorption at expense of K+ and H+ ions which are lost in the urine.
Where do loop diuretics work?
Thick Ascending Limb
Where do aldosterone (Potassium Sparing) diuretics work?
Collecting Tubule
What are characteristics of aldosterone (potassium sparing diuretics such as spironolactone and amiloride?
-Prevent K+ secretion by antagonizing effects of aldosterone in collecting tubules (spironolactone)
or
- prevent Na+ influx through icon channels in the luminal membrane (amiloride)
- can be used with loop diuretics to offset hypokalemia
- not used with ACE -1
What is an example of an osmotic Diuretic?
mannitol
Where do osmotic Diuretics work and how?
Thin Descending Limb
- Mannitol stays in the urine (not reabsorbed) and so it absorbs more fluid into the urine.
What is Mannitol (Osmotic Diuretic) used for?
Increased intracranial pressure after head trauma.
*NOT hypertension
What is an example of a Carbonic Anhydrase Inhibitor?
Acetazolamide (Diamox)
Where do Carbonic Anhydrase Inhibitors (Acetazolanide) work and how?
Proximal Convoluted Tubule
-Shuts down reabsorption of H2CO3 into interstitial space = less Na+ reabsorption and more Na+ in lumen.
What is Acetazolanide (Diamox) used for?
Glaucoma and epilepsy
*NOT hypertension
What are examples of types of drugs that Alter Sympathetic Tone?
- Beta Blockers (Sympathoplegics)
- Alpha 1 Blockers
- Alpha 2 Agonists
How do Beta Blockers (sympathoplegics) work to treat hypertension and what are examples of these drugs?
They reduce sympathetic tone. (decrease BP)
- Propanolol (non-selective)
- Atenolol (B1)
- Metoprolol (B1)
What are examples of Alpha 1 Blockers and how do they work?
- Prazosin and Terazosin (Cardioselective)
- Phentolamine and Phenoxybenzamine (Noncardioselective (a1 and a2))
- Vasodilation
What is an example of an Alpha 2 AGONIST used to treat hypertension
Clonidine (Catapres)
What is are examples of a combined Beta and Alpha 1 agonists used for hypertension?
Lebetalol (Trandate)
Carvdilol (Coreg)
What are some examples of direct Vasodilators?
Hydralazine
Minoxidil
Nitroprusside (Also relaxes veins)
Nitroglycerine
How does the direct vasodilator Minoxidil work?
Hyperpolarizes smooth muscle by opening K+ Channels
What are some examples of Calcium Channel Blockers used to treat hypertension?
Verapamil
Diltiazem
Nifedipine
What is an example of a ganglionic blocker?
Mecamylamine
*rarely used due to Nasty Side-Effects
By what 2 mechanisms is angina treated?
- Vasodilation (Increase flow)
- Nitrates and Nitrites
- Decrease O2 consumption
- B Blockers; Ca++ channel blockers
How do Nitrates/Nitrites work to treat angina?
Metabolize Nitric oxide to increase cGMP therefore relaxing smooth muscle and dilating cardiac vessels
What are some examples of Nitrates/Nitrites?
Nitroglycerine
Amyl nitrate
