The following are key points to remember
from this review about the use of
cardiovascular medications during pregnancy:
General Consideration
1- Several hemodynamic and physiologic
Adaptations occur during pregnancy and
the pharmacokinetics of CVS medications
can change throughout gestation.
2- Data on medication safety are often drawn
from observational studies and expert opinion.
3- Food and Drug Administration has replaced
the ABCDX classification system for labeling
the safety of medications during pregnancy
with a narrative labeling system.
4- The Pregnancy and Lactation Labeling Rule
(PLLR) is intended to provide more information
about available data, clinical considerations,
and differences in degrees of fetal risk.
5- In Emergency Situations Standard medications
should be used for treatment of cardiopulmonary
resuscitation or cardiogenic shock.
ARRHYTHMIA
• Arrhythmia in Unstable Patient should be
treated with electrical cardioversion.
• Antiarrhythmic medications should be
avoided in first trimester if possible, and
the lowest effective dose should be used.
• Amiodarone should be avoided
due to the risk of fetal thyroid and
neurodevelopmental complications.
1- Supraventricular tachycardia (SVT) :-
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• SVT can be treated initially with vagal maneuvers,
then adenosine, beta-blockers, and
verapamil as third-line therapy.
• Beta-blockers (with or without digoxin) or
oral verapamil can be used for suppressive
therapy for SVT in the absence of pre-excitation.
• Sotalol or flecainide can be considered in
the absence of structural heart abnormalities.
• In Wolff-Parkinson-White (WPW) syndrome,
flecainide or propafenone are recommended
for the prevention of SVT.
2- Atrial Fibrillation and Atrial Flutter :-
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• AFib & AFlut can be treated with beta-blockers,
verapamil, and digoxin.
• Sotalol, flecainide, and propafenone can be
considered if rhythm-control is needed.
• Intravenous procainamide is used for the
treatment of atrial fibrillation with pre-excitation
(wide complex tachycardia).
3- Beta-blockers :-
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• Beta-blockers are used frequently for treatment
of several CVS conditions during pregnancy.
• Beta-blockers in Large, retrospective studies
shows no association with major congenital abnormalities.
• Beta-blockers are associated with :-
Intrauterine growth restriction
(small for gestational age infants),
Increased risk of preterm birth, and
Neonatal bradycardia and hypoglycemia.
• Atenolol is not recommended due to
increased risk of fetal growth restriction.
4- DIGITALIS
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• Digoxin can be used during pregnancy.
• Of note, the assay for measuring digoxin levels
during pregnancy can result in falsely elevated
levels due to circulating digoxin-like fragments.
5- ANTI-ARRHYTHMICS
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• Flecainide can be used during pregnancy.
Adverse Effects include :-
-
Maternal visual disturbance,
-
Maternal QT interval prolongation,
-
Neonatal QT intervals prolongation and
-
Heart failure at toxic levels,
-
Cholestasis of pregnancy, and
-
Fetal heart rate variability decreased.
• Limited data exist about the use of propafenone during pregnancy.
• Sotalol portends increased risk of
torsades de pointes due to QT prolongation and
is typically only used for fetal arrhythmias.
6- Ventricular tachycardia (VT):-
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• Electric cardioversion should be performed
for Unstable VT.
• If a pregnant woman is Hemodynamically Stable,
Electric cardioversion or Lidocaine or
Beta-blockers can be considered.
• European Society of Cardiology guidelines
suggest procainamide, flecainide, or sotalol.
• Amiodarone should only be used
if other treatments are ineffective.
HYPERTENSION
1- The placenta does not autoregulate blood
flow; therefore, acute maternal hypotension
due to antihypertensive treatment may cause
Fetal Distress.
2- First-line agents for chronic or gestational HTN
include Labetalol, Nifedipine, and Methyldopa.
Dose reduction may needed in second trimester
when a 5-10 mm Hg decrease in mean BP
due to the physiologic changes of pregnancy.
Diuretics can cause placental Hypoperfusion.
HEART FAILURE
1- Beta-blockers can be used
2- Digoxin can be considered.
3- Diuretics can be used for pulmonary Edema
(furosemide, bumetanide, hydrochlorothiazide)
but excessive dosing carries risk of placental
hypoperfusion & fetal electrolyte abnormalities.
4- During pregnancy, hydralazine plus nitrates
can be used for afterload reduction
5- ACE inhibitors, Angiotensin-receptor blockers,
Direct renin-inhibitors, Angiotensin receptor
neprysilin inhibitors, spironolactone, and
eplerenone are contraindicated.
6- Enalapril, captopril, and benazepril can be
safely considered during lactation.
DYSLIPIDEMIA
1- Statins considered Contraindicated during
pregnancy, although no associations with birth
defects were found in , observational,
prospective trial and recent systematic review.
2- Gemfibrozil, Fenofibrate, and Ezetimibe
are also considered potentially teratogenic.
Anticoagulation for Mechanical Valves
1- Embryopathy, Miscarriage, and Stillbirth
Common with daily doses of warfarin >5 mg.
2- If the warfarin dose is >5 mg/day,
Should Switch to (LMWH) or (UFH) Heparin
By the End of the Sixth week of gestation
To decrease the risk of warfarin embryopathy.
3- LMWH does not cross the placenta.
Meticulous monitoring of peak and
trough anti-Xa levels need to be followed.
4- Transition between warfarin and LMWH
are times of increased risk for valve thrombosis
and thromboembolic risk.
5- Women who are receiving warfarin should be
changed to LMWH or UFH at 36 weeks’
gestation to reduce the risk of fetal hemorrhage
and maternal bleeding at the time of delivery.
6- Regional anesthesia cannot be given
within 24 hours of the last dose of LMWH.
7- Cesarean delivery should be performed
if a mother arrives in labor while on warfarin.
8- Reversal of warfarin with vitamin K in
the mother does not ensure reversal in the fetus.
Antiplatelet Medications
1- Low-dose aspirin is considered safe
during pregnancy and lactation, and
2- ASA commonly used for prevention of pre-eclampsia.
3- High-dose aspirin should be avoided due to
Risk of premature closure of ductus arteriosus.
4- Clopidogrel has been used in pregnancy but
since there are limited data, it is recommended
to use it for the shortest duration possible.
5- Clopidogrel must be discontinued 7 days prior
to neuroaxial anesthesia to decrease the risk
of epidural hematoma.
Pulmonary Arterial Hypertension
1- Parenteral and inhaled prostaglandins can be
used in the appropriate setting and
phosphodiesterase-5 inhibitors may considered.
2- Endothelin receptor blockers
(bosentan, ambrisentan, macitentan)
are teratogenic and should not be used.
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FDA Pregnancy Categories
A: Generally Acceptable.
Controlled studies in pregnant women
Show No evidence of fetal risk.
Example drugs : levothyroxine,
folic acid, liothyronine
B: May be Acceptable.
Either Animal studies show No risk But
Human studies Not available
-OR-
Animal studies showed Minor risks and
Human studies done and showed No risk.
Example drugs: metformin, amoxicillin
hydrochlorothiazide,cyclobenzaprine
C: Use with caution if benefits outweigh risks.
Animal studies show risk and
human studies not available
-OR-
Neither Animal Nor Human studies done.
Example drugs: gabapentin, amlodipine, trazodone
D: Use in LIFE-THREATENING Emergencies
When No safer drug available.
Positive evidence of Human Fetal risk.
Example drugs: losartan
X: Do Not Use in Pregnancy.
Safer alternatives exist.
Risks involved outweigh potential benefits.
Example drugs: atorvastatin, simvastatin,
methotrexate, finasteride