LM 15.7: Hypertensive Disorders of Pregnancy

Question 1

which drugs are used to treat acute severe HTN?

Answer 1

1. labetalol
2. hydralazine
3. immediate release nifedipine

Question 2

MOA, metabolism and speed of labetalol?

Answer 2

selective alpha 1 and nonselective B blocker

causes vasodilation and reduces CO

metabolized in the liver

10 minute onset IV, 2 hr onset orally

Question 3

MOA, metabolism and speed of nifedipine?

Answer 3

calcium channel blocker into smooth muscle

oral instant release works in 10-15 minutes

liver metabolism

Question 4

MOA, metabolism and speed of hydrazine?

Answer 4

directly dilates peripheral vessels –it alters intracellular Ca release and interferes with smooth muscle Ca influx leading to inhibition of phosphorylation of myosin protein leading to increase in HR, SV and CO

metabolized in liver

IV onset in 10-20 minutes

Question 5

MOA, metabolism and speed of methyldopa?

Answer 5

not used for acute HTN but often used for chronic HTN in pregnancy

centrally stimulates alpha 2 adrenergic receptors

it’s a phenylalanine derivative and aromatic amino acid decarboxylase inhibitor

Question 6

which HTN medications shouldn’t be used during pregnancy?

Answer 6

1. ACE inhibitors
   dont use in 2nd half of pregnancy because can cause renal abnormalities
2. mineralocorticoid receptor agonists
   ex. spironolactone

anti-androgenic activity causes feminization of male fetus

Question 7

why wouldn’t you give Mg prophylactically to prevent seizures in a pregnant woman who has myasthenia gravid?

Answer 7

since Mg blocks intracellular Ca influx at the neuromuscular junction it can result in profound muscular weakness and respiratory failure aka it makes MG even worse than it already is

Question 8

what is preeclampsia?

Answer 8

HTN disorder diagnosed after 20 weeks gestation

eclampsia is new onset seizures with a women with preeclampsia