HTN in Pregnancy

Question 1

Intravenous labetalol and hydralazine (+ nifedipine)

Answer 1

HTN in pregnancy
- First line Drug for Acute HTN
Hydralazine MOA:
o Direct acting arterial vasodilator, given IV for acute HTN in pregnancy
Labetolol MOA:
o Selective Alpha-1- blocker = vasodilate
o Non selective Beta-1 block = decreased CO
Nifedipine (-dipine)
o Calcium Channel Blocker = arterial vasodilator
o Fast release gel caps for acute, slow release tabs for chronic

Question 2

Methyldopa (and Labetalol)

Answer 2

HTN in pregnancy
- First line Drug for Chronic HTN
MOA
- Converted into the metabolite, alpha-methylnorepinephrine, in the CNS
- stimulates the central inhibitory alpha-2-adrenergic receptors–>leading to a reduction in sympathetic tone, total peripheral resistance, and blood pressure

Question 3

Magnesium sulfate

Answer 3

HTN in pregnancy
- First line Drug eclampsia
- Unique calcium antagonist=an anticonvulsant
MOA
- It inhibits calcium movement through its channels in a variety of tissues
o Relaxes smooth muscle, DEC platelet aggregation and INC release of NO.
o INC the seizure threshold by *inhibiting NMDA receptors, limiting the effect of glutamate.
Direct Antidote to Magnesium Toxicity
• 10% Calcium Gluconate