5. HTN & Antianginal Flashcards
What is the key diuretic?
HCTZ
What is HCTZ?
Diuretic
Effects of HCTZ? Uses? Adverse effects?
Acutely decreases blood volume (baroreflex nuetralizes this effect long term)
Chronic Na depletion leads to decreased PR
Mild HTN or combo to prevent tolerance
K loss (drowsiness) & arrhythmia
Effects of beta blocker (or partial beta agonist)?
Decreased HR
Decreased renin release
partial ag has smaller effect
Effects of alpha antag?
Decrease PR
May increase blood volume due to decrease perfusion of kidney
What are the ACE inhibitors? Difference between them?
Captopril (active)
Enalapril (prodrug)
What is Captopril?
ACE inhib
What is Enalapril?
ACE inhib
Effects of ACE inhibitor?
LEss Ang II –> decreaser PR & less aldosterone (lower blood volume)
Bradykinin buildup –> decreased PR [y works even in people with low renin levels]
ACE inhibitors are still effective on some individual who are shown to have low renin levels. How?
Buildup of bradykinin –> decreased PR
What is the key Ang II receptor blocker?
Losartan
What is losartan? Effects?
Ang II blocker
Decreased PR
What are the Ca Channel blockers? Difference?
Nifedipine
Diltiazem
Verapamil
Nife doesn’t effect the heart like the other 2
What are the effects of Ca channel blockers?
Decreased PR Decreased HR (not nife)
What is the key vasodilators? Difference?
Hydralazine (effects arteries more)
Nitroproside (effects arteries & veins the same)
What is hydralazine? Effects?
Vasodilator
Decrease PR mainly in the arterioles (less so in the venoules)
Reflex increase in blood volume & CO
Mechanisms of vasodilators?
NO release –> cGMP
What is the adrenergic neuron blocker?
Reserpine
What are the CNS acting drugs?
Alpha methyl dopa
Clonidine
How is coronary circulation different than systemic circulation?
Flow during diastole instead of systole
Heart already extracts all O2 from blood, so during strenuous situations the blood flow must increase a lot to meet demand
What % of CO goes to coronary circulation during rest? During stress?
5%
15%
What determines O2 demand of heart? Supply?
how much work the heart is doing (= Contracility, HR, preload & afterload)
Coronary patency, diastolic BP, blood O2 capacity & collateral circulation
What are the 3 types of Angina Pectoris?
Stable/typical
Unstable/Atypical
Variant/Prinzmetal
How does stable/typical angina present? Cause? Best treatment?
Heavy substernal discomfort on exertion
Artherosclerotic narrowing (always narrow)
Nitro
How does unstable/atypical angina present? Cause?
Discomfort no matter what
Plaque rupture & thrombosis
What is Nitroglycerin? How does it work?
Selective venodilator
Venous dilation –> decreased cardiac return –> decreased preload –> decreased EDV –> decreased O2 demand
Smaller effect = coronary dilation –> more blood supply
How is nitroglycerin administered? Why?
Sublingual or trandermal
Can’t be taken orally cuz metabolized really fast
What is the effect of high dose of Nitro?
Big decreased in CO –> Reflex tachycardia to compensate –> increased O2 demand off sets desired decrease in O2 demand
What is the normal nitro pathway? Pathway during NO administration?
Ach or histamine –> activation of nitro oxidase in endothelial cell –> Arginine split into NO & arginine
No diffuses into smooth muscle –> guanyl cyclase –> GTP –> cGMP –> muscle relaxation
Administered NO goes straight to smooth muscle cell
How does Varient/Prinzmetal angina present? Cause? Best treatment?
“Random” chest pain
Coronary vasospasm due to autonomic stimulation or underlying plaque
Ca Channel blocker
Uses of Isosorb mono-dinitrate?
oral prophylaxis for angina
Adverse effects of nitrates?
headache, hypotension, tachycardia
How is nitrate tolerance prevented
8 hour free period
If take patch, take it off while sleep
Nitroglycerin uses?
Acute angina
Beta blocker usage for angina?
Prophylaxis
Drug combos for angina?
Nitrates plus beta blocker (decreased )2 demand without relfex tachycardia)
Nitrates & verapamil/diltazem (decrease O2 demand & increase supply)
Nitrates & nifedipine (hypotension & tachycardia)
Beta blocker & verapamil/diltazem (enhacned cardiac suppression)
Beta Blocker & nifedipine (blunter reflex)
