Hypertension

Question 1

Methyldopa: mechanism of action?

Answer 1

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.

Question 2

Clonidine: mechanism of action?

Answer 2

Alpha-2 adrenoreceptor stimulant.

CO is unchanged or increased, renal bloodflow (RBF) is unchanged.

Question 3

Prazosin: mechanism of action?

Answer 3

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.

Question 4

Calcium channel blockers: mechanism of action?

Answer 4

Inhibit transmembrane calcium influx, blocking smooth muscle contraction.
Cause vasodilation and reduction in peripheral resistance.
No effect on cardiac output or RBF.

Question 5

ACE inhibitors: mechanism of action?

Answer 5

Inhibits enzyme that converts AgI to AgII causing vasodilation.
Increase vasodilating PGs and inhibit release of bradykinin.
No effect on CO or RBF.

Question 6

Hydralazine: mechanism of action?

Answer 6

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

Question 7

Labetalol: mechanism of action?

Answer 7

Mixed alpha and beta adrenergic blocker.

CO and RBF unchanged.

Question 8

Metoprolol: mechanism of action?

Answer 8

Selective beta-1 adrenergic blocker

Question 9

Thiazide diuretics: mechanism of action?

Answer 9

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

Question 10

How can you qualify for the diagosis of superimposed preeclampsia?

Answer 10

New onset proteinuria >300mg (without proteinuria) OR A sudden increase in proteinuria or hypertension OR Platelets Increased AST or ALT >70

Question 11

What’s the proper way to assess BP?

Answer 11

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

Question 12

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

Answer 12

1200mg/day

Question 13

Max dose of Nifedipine?

Answer 13

120 mg/day

Question 14

What very rare reaction has been reported when Ca-channel blockers and magnesium are combined, and how is it reversed?

Answer 14

Neuromuscular blockade (reversed with calcium gluconate)

Question 15

Conditions associated with previable HELLP

Answer 15

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

Question 16

Benefits of magnesium for preeclampsia, compared to placebo

Answer 16

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.

Question 17

Benefits of dexamethasone for HELLP

Answer 17

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.