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Flashcards in Hypertension Deck (17):
1

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.

2

Clonidine: mechanism of action?

Alpha-2 adrenoreceptor stimulant.
CO is unchanged or increased, renal bloodflow (RBF) is unchanged.

3

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.

4

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.

5

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.

6

Hydralazine: mechanism of action?

Direct peripheral vasodilator which acts on vascular smooth muscle.
CO is increased, RBF is unchanged or increased.

7

Labetalol: mechanism of action?

Mixed alpha and beta adrenergic blocker.
CO and RBF unchanged.

8

Metoprolol: mechanism of action?

Selective beta-1 adrenergic blocker

9

Thiazide diuretics: mechanism of action?

Followed by a long-term decrease in PVR (related to decreased intracellular Na in smooth muscle).

10

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

11

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

12

Maximum dose of Labetalol (current first line therapy for HTN in pregnancy)

1200mg/day

13

Max dose of Nifedipine?

120 mg/day

14

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)

15

Conditions associated with previable HELLP

partial mole/triploidytrisomy 13antiphospholipid syndromeautoantibodies to angiotensin AT(1)- receptorsevere preterm preeclampsia with Ì¢‰âÒmirrorÌ¢‰âÂå syndrome

16

Benefits of magnesium for preeclampsia, compared to placebo

59% reduction in the risk of eclampsia (number needed to treat for an additional beneficial outcome: 100) 36% reduction in abruption, and nonstatistically significant but clinically important 46% reduction in maternal death.

17

Benefits of dexamethasone for HELLP

no difference in the risk of maternal death, maternal death or severe maternal morbidity, or perinatal/infant death. The only significant effect of treatment on individual outcomes is improved platelet count: This effect is strongest if the treatment is started antenatally.