Summary Safety Review - Amiodarone (intravenous) - Assessing the potential risk of side effects in fetuses and newborns

Review decision

A Summary Safety Review complements other safety related information to help Canadians make informed decisions about their use of health products. Each summary outlines what was assessed in Health Canada’s review, what was found and what action was taken by Health Canada, if any.


Issued: 2017-01-06

Product

Amiodarone (intravenous)

Potential Safety Issue

Side effects in fetuses and newborns

Key Messages

  • Amiodarone is a prescription drug authorized for sale in Canada to treat life-threatening abnormal heart rhythms (arrhythmias) in adults. Health Canada is aware that amiodarone is prescribed by some doctors during pregnancy, to treat the mother or fetus, or to treat newborns.
  • Health Canada reviewed the risk of side effects in fetuses and newborns exposed to intravenous amiodarone, because of a product information update in the United States.
  • Health Canada's review concluded that there may be a link between amiodarone use during pregnancy or in newborns and the risk of side effects on the heart. Health Canada has requested that manufacturers update the product information for intravenous amiodarone products to inform healthcare professionals about this risk.

Overview

Health Canada reviewed the potential risk of side effects in fetuses and newborns with intravenous amiodarone, because of a product label update in the United States which included warnings about the potential for effects on the heart, nervous system, development and growth of fetuses and newborns. Health Canada reviewed the available evidence regarding side effects on the heart, hypothyroidism (less than normal levels of thyroid hormone) in newborns and developmental delays occurring in fetuses and newborns exposed to amiodarone.

Use in Canada

  • Amiodarone is a prescription drug authorized for sale in Canada to treat life-threatening abnormal heart rhythms (arrhythmias) in adults.
  • Amiodarone is available as an oral medication or as an intravenous injection. Intravenous amiodarone has been marketed in Canada since 2000. These products are available by prescription only.
  • Health Canada is aware that amiodarone is prescribed by some doctors for the treatment of life-threatening arrhythmias in fetuses and newborns when other medications have not worked.
  • Use of amiodarone to treat pregnant women is uncommon and its use is considered only if the potential benefit to the mother outweighs the risk to the fetus.

Safety Review Findings

  • At the time of the review, Health Canada received 3 Canadian reportsa and retrieved 12 additional reports from published literature about serious side effects on the heart including potentially fatal heart attacks in newborns who received amiodarone for life-threatening abnormal heart rhythms. In 13 of the 15 reports reviewed it was determined that amiodarone may have played a role in the side effects.
  • A published study of amiodarone use in children1 suggested that the risk of low blood pressure (hypotension), slow heartbeat (bradycardia) and problems with the electrical activity of the heart (atrioventricular block) may be greater than in adults exposed to amiodarone.
  • Having less than normal levels of thyroid hormone (hypothyroidism) can be caused by amiodarone exposure in utero and is a known cause of developmental delays (such as in learning, speech and movement) if untreated. However, some children have had developmental delays following amiodarone exposure despite having normal levels of thyroid hormone.
  • Abnormal heart rhythm is a risk factor for heart attack, death, developmental delays, premature birth, even in the absence of amiodarone.

Conclusions and actions

  • Health Canada's review of the available information did not establish a link between the use of amiodarone during pregnancy and the risk of developmental delays in newborns but did find a possible link to side effects on the heart.
  • Health Canada requested that the manufacturers update the product information for intravenous amiodarone products with regard to heart risks in newborns. Although this information is already included regarding adult patients, it is important that health care professionals recognize that there are potential risks when using this drug in newborns and infants.
  • Health Canada will continue to monitor safety information involving amiodarone, as it does for all health products on the Canadian market, to identify and assess potential harms. Health Canada will take appropriate and timely action if and when any new health risks are identified.

Additional information

The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this drug both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.

References

  1. Saul JP, et al. Intravenous amiodarone for incessant tachyarrhythmia in children. A randomized, double-blind, antiarrhythmic drug trial. Circulation 2005;112:3470-3477.

Footnotes

  1. Canadian reports can be accessed through the Canada Vigilance Online Database.