Antihypertensive therapy in pregnancy

Question 1

When do the SOMANZ guidelines recommend commencing antihypertensive therapy in pregnancy?

Answer 1

in all women with systolic BP>160mmHg or diastolic BP >110mmHg
treatment of mild hypertension depends on discretion of clinician and clinical picture

Question 2

What are the main antihypertensive drugs used in pregnancy?

Answer 2

First line
- methyldopa
- clonidine
- labetalol
- oxepranalol
Second line
- nifedipine
- prazosin
- hydralazine

Question 3

What is the definition of hypertension in pregnancy

Answer 3

SBP greater than or equal to 140 and/or DBP greater than or equal to 90

Question 4

What is usual aim of antihypertensive therapy?

Answer 4

• prevention of severe hypertension and eclampsia

- prolong pregnancy to allow for fetal maturation, particularly lung maturation, to reduce risks of birth

Question 5

What is the mode of action of methyldopa?

Answer 5

• acts centrally to stimulate alpha adrenergic receptors to down regulate stimulation of the peripheral sympathetic nervous system

Question 6

What is the trade name of methyldopa?

Answer 6

Aldomet or Hydopa

Question 7

What is the stock strength and usual dose of methyldopa?

Answer 7

• 250mg tablets
• started at 250-750mg PO TDS, then titrated to effect
• max dose is 3g/day

Question 8

What precautions/side effects are important to be aware of with methyldopa?

Answer 8

• slow onset of action over 24 hours
• dry mouth
• sedation
• depression
• blurred vision
• anaemia
• interferes with some laboratory tests

Question 9

What classes of antihypertensives are usually contraindicated in pregnancy?

Answer 9

• ACE inhibitors as they have been associated with third trimester fetal death and neonatal renal failure