OB Emergency Meds

Question 1

Hydralazine
MOA/Dose/AE
CIN

Answer 1

MOA: vasodilator thus reduced BP
Dose: 5/5/10 mg , check BP in 20 minutes
Max dose: 20 mg
Onset: 10-20 min
A/E: maternal HA, hypotension, FHR abnormalities
CIN: CAD, rheumatic heart disease of mitral valve

Question 2

Magnesium sulfate
Dose
How to draw up the solution

Answer 2

4 grams over 15 minutes

Use 20 ml syringe, draw up 4 grams MgSo4 50%, (8 ml) + 12 ml sterile saline = (20% solution).

Question 3

Labetalol
MOA/Dose/A/E
CIN

Answer 3

MOA: beta agonist
Dose: 200 BID
20/40/80 IV push over 2 min, check BP every 10 min
Onset: minutes
Max daily dose: 300 mg
CIN: asthma, heart disease (MI/heart block), bradycardia

If not working… switch to Hydralazine 10 mg

Question 4

Magnesium - tocolytic
MOA/Dose/A/E
CIN
Cautions

Answer 4

MOA: reduces calcium in uterine muscle, thus relaxes muscle
Dose: 4 grams followed by 1 gram per hour
Maternal A/E: flushing, diaphoresis, nausea, toxicity
Fetal A/E: neonatal depression
CIN: myasthenia Gravis, hypocalcemia, mod/sever renal failure, cardiac ischemia/heart block, myocarditis

When used with Nifedipine: suppressed heart rate and decreased LVP, neuromuscular blockade

When used with Terb: caution

Question 5

Magnesium
Toxicity Values
How to administer (for severe pre-eclamspia/eclampsia)
How to dose adjust for renal impairment?

Answer 5

Toxicity values: 9/12/30 mg/DL
Dose: 4 gram bolus over 20 minutes, then 2 grams/hr

If Cr>1 or Oliguria: 4 grams bolus followed by 1 gram/hour, check serial mag q 4 hours

Question 6

Magnesium dosing (if you can’t get an IV)

Answer 6

5 g x 2 each buttocks
then 5 gram q 4 hrs

Question 7

Nifedipine po
MOA
Dose
A/E
CIN

Answer 7

MOA: CCB
Dose: 10 mg PO
Repeat BP in 20 min, Can give 20 mg if elevated
Max dose: 180 mg daily

Onset: 10 min

A/E: reflex tachycardia, maternal HA

CIN: concomitant use with rifampin, phenobarbital (CYP)

Question 8

Oxytocin Labor
Dose
Where is it made?

Answer 8

Dose: 1-2 mill unit every 30 minutes
MOA: increases calcium levels in uterine muscle, stimulates prostaglandin

Produced in hypothalamus, and stored in the posterior pituitary

Question 9

Magnesium toxicity
-oliguria defined/risk
- what to do if serum mag high?

Answer 9

oliguria: <30 ml UOP per hour x 4 hours
check serial mags
if serum mag >9.6 mg/dL ==> stop mag and check mag q 2 hours

Question 10

Prostaglandin- Cytotec

MOA/Dose/A/E
CIN

Answer 10

MOA: prostaglandin E1
Dose: 25 mcg q 4 hours
A/E tachysystole
CIN: prior uterine scar > 28 weeks

Question 11

Tranxexamic Acid
-MOA
-Dosing
-CIN

Answer 11

plasmin inhibitor, stabilizes fibrin matrix
1 gram IV in 100 ml solution, given over 10 minutes
CIN: history of color blindness, VTE, concomitant use of COCP