Hypertension COPY Flashcards
Methyldopa: mechanism of action?
Acts centrally by stimulating central alpha-2 receptor via its active metabolite alpha-methylnorepinephrine.
It might act as a peripheral alpha-2 blocker by acting as a false neurotransmitter.
Reduces SVR without causing change in CO, renal bloodflow is maintained.
Clonidine: mechanism of action?
Alpha-2 adrenoreceptor stimulant.
CO is unchanged or increased, renal bloodflow (RBF) is unchanged.
Prazosin: mechanism of action?
Selective alpha-1 post-synaptic blocker
Reduces both SBP and DBP.
Vasodilates both resistance and capacitance vessels reducing both preload and afterload without affecting RBF.
Calcium channel blockers: mechanism of action?
Inhibit transmembrane calcium influx, blocking smooth muscle contraction.
Cause vasodilation and reduction in peripheral resistance.
No effect on cardiac output or RBF.
ACE inhibitors: mechanism of action?
Inhibits enzyme that converts AgI to AgII causing vasodilation.
Increase vasodilating PGs and inhibit release of bradykinin.
No effect on CO or RBF.
Hydralazine: mechanism of action?
Direct peripheral vasodilator which acts on vascular smooth muscle.
CO is increased, RBF is unchanged or increased.
Labetalol: mechanism of action?
Mixed alpha and beta adrenergic blocker.
CO and RBF unchanged.
Metoprolol: mechanism of action?
Selective beta-1 adrenergic blocker
Thiazide diuretics: mechanism of action?
Followed by a long-term decrease in PVR (related to decreased intracellular Na in smooth muscle).
How can you qualify for the diagosis of superimposed preeclampsia?
New onset proteinuria >300mg (without proteinuria) OR A sudden increase in proteinuria or hypertension OR Platelets Increased AST or ALT >70
What’s the proper way to assess BP?
Cuff 1.5x upper arm circumference with bladder that encircles >80% of the arm Arm at the level of the woman’s heart Patient seated, at rest ÌâåÊ
Maximum dose of Labetalol (current first line therapy for HTN in pregnancy)
1200mg/day
Max dose of Nifedipine?
120 mg/day
What very rare reaction has been reported when Ca-channel blockers and magnesium are combined, and how is it reversed?
Neuromuscular blockade (reversed with calcium gluconate)
Conditions associated with previable HELLP
partial mole/triploidytrisomy 13antiphospholipid syndromeautoantibodies to angiotensin AT(1)- receptorsevere preterm preeclampsia with Ì¢‰âÂÒmirrorÌ¢‰âÂå syndrome