Propranolol is a beta-blocker drug prescribed for the treatment of cardiac issues such as irregular heart rate and hypertension. Propranolol during pregnancy is seldom prescribed since beta-blockers may pose a risk to the developing fetus. The drug may be prescribed as a last resort when other medicines yield no results.
You must consult your doctor before consuming propranolol or other beta-blockers to minimize possible side effects. Read on to know about the safety of using propranolol during pregnancy, the dosage instructions, side effects, and dosage precautions that should be kept in mind.
What Is Propranolol?
Propranolol can especially help in:
- Treating irregular heartbeats
- Preventing future heart attacks and strokes
- Preventing chest pain due to angina
It also helps in reducing symptoms of excessive thyroid hormone in the body. It is available in tablet, capsule, and liquid form.
Is It Safe To Take Propranolol During Pregnancy?
The US Food and Drug Administration has categorized propranolol under “pregnancy category C.” This means animal studies have shown that the drug has adverse effects on the fetus, and there are no well-controlled studies in pregnant women (2).
While hypertension and cardiac issues can make pregnancy risky, taking medication that can harm your baby is not a good idea. As there are no well-controlled studies in pregnant women and the available studies suggest adverse effects of propranolol to the developing fetus, this drug should be taken during pregnancy only if the potential benefits outweigh the risks.
How Does Propranolol Effect Pregnant Women?
An animal study on rats found that oral administration of propranolol through pregnancy led to reduced neonatal weight and litter size. In humans, the observations could be interpreted to the increased muscle tone of the uterus, and instability in blood flow (3).
Mothers who were given propranolol Hcl at the time of labor showed signs of bradycardia (slow heart rate), hypoglycemia, and/or respiratory depression (2). Talk to your doctor and discuss if there are any safer alternatives to propranolol.
US FDA recommends the following doses for each condition (4). However, your doctor will decide the dosage after considering your requirements.
- The recommended dosage for hypertension is 40mg twice a day, and it is not known to cause any adverse effects during pregnancy (5).
- Although the FDA recommends 80mg-320 mg for angina pectoris, studies proved that a dosage of more than 160 mg could cause adverse effects on the fetus. So, professional advice is needed (5).
- 1mg to 30mg three or four times daily for atrial fibrillation
- The initial dosage for myocardial infarction is 40mg, and after one month, it can be 60mg to 80mg.
- Initial dosage for migraine is 80mg, but the effective dose range is 160mg or 240mg per day; it should be taken after consulting a medical professional.
Whether taken in the prescribed dosages or otherwise, propranolol can have certain side effects in the patients.
Side Effects Of Propranolol During Pregnancy
Propranolol has some common side effects on the mother (6).
- If the mother has an intolerance to propranolol tablets, then she could experience a slow heart rate, low blood pressure, dizziness, light-headedness, blurred vision.
- A few common side effects include tiredness, weakness, cold extremities, difficulty in sleeping, irregular heartbeat, Raynaud’s syndrome, and nightmares.
If you do take propranolol during pregnancy and experience any of these symptoms, then stop taking the medication and contact your doctor immediately.
Frequently Asked Questions
Now, let us go through some frequently asked questions regarding propranolol use during pregnancy.
1. Is it okay to take propranolol occasionally during pregnancy?
Do not take propranolol occasionally, as the withdrawal of the medicine from your system should be gradual, over 10 to 14 days. You may experience unpleasant side effects such as sweating, shaking, worsening of angina, irregular or fast heartbeat, heart attack, or even death in some cases (6).
Also, medications for hypertension and anxiety need to be taken continuously for a certain period. So always discuss with your doctor before starting or stopping the medication and stick to the prescribed dosage.
2. What if I have already taken propranolol during pregnancy?
So, if you are already under medication, and found out that you are pregnant, then talk to your doctor to decide the best course of action, as abruptly stopping the drug is not safe.
3. Can propranolol cause miscarriage?
4. Can taking propranolol during pregnancy cause stillbirth?
A study conducted based on the data from the Danish Fertility Database, the Danish National Hospital Register, and the National Prescription Register found that a higher rate of perinatal mortality was found among women exposed to beta-blockers (8). So, there is a chance of stillbirth upon the usage of propranolol during pregnancy.
5. Can taking propranolol during pregnancy cause any birth defects?
A paper published in The Journal of Pediatrics states that infants born to mothers who received continuous propranolol therapy during pregnancy reported a small placenta, intrauterine growth retardation, fetal depression at birth, postnatal hypoglycemia, and bradycardia (9).
Propranolol is a beta-blocker usually prescribed for conditions such as high blood pressure, migraine, and anxiety. The doctor will prescribe it to you if they find that the benefits outweigh the risks. However, there are not enough studies done on humans to establish the safety of propranolol in expecting mothers. Research on animals has shown adverse effects on the fetus, and therefore you should not take propranolol during pregnancy without your doctor’s consent.
This post is for informational purposes only and is not a replacement for a doctor’s consultation. Do not use any medication without talking to your doctor.
2. Prescribing Information-Innopran XL; The US Food and Drug Administration
3. N. Shoenfeld et al.; Effects of Propranolol during Pregnancy and Development of Rats. I. Adverse Effects during Pregnancy; Tel Aviv University
4. Gwendolyn R. Gladstone M.D,Gwendolyn R M.D, Gladstonea,b, M.D. Allan Hordofa,b, Welton M. Gersonya,b M.D; Propranolol administration during pregnancy: Effects on the fetus; The Journal of Pediatrics
5. Inderal Tablets; The US Food and Drug Administration
6. E.A. Taylor, P. Turner; Anti-hypertensive therapy with propranolol during pregnancy and lactation; British Medical Journal
7. Package leaflet: Information for the patient; The Electronic Medicines Compendium (EMC)
8. Mohammed Y Yakoob et al.; The Risk of Congenital Malformations Associated With Exposure To Beta-Blockers Early In Pregnancy: A Meta- Analysis; NCBI (2013)
9. Kasper Meidahl Petersen et al.; β-Blocker treatment during pregnancy and adverse pregnancy outcomes: a nationwide population-based cohort study; British Medical Journal