The US Food and Drug Administration is warning that terbutaline administered by injection or through an infusion pump should not be used in pregnant women for prevention or prolonged (beyond 48-72 hours) treatment of preterm labour due to the potential for serious maternal heart problems and death. In addition, oral terbutaline tablets should not be used for prevention or treatment of preterm labour. The FDA is requiring the addition of a Boxed Warning and Contraindication to the drug prescribing information (labelling) to warn against these uses.

Terbutaline is FDA-approved to prevent and treat narrowing of the airways (bronchospasm) associated with asthma, bronchitis, and emphysema. The drug is used off-label for obstetric purposes, including treating preterm labour and treating uterine hyper-stimulation. Terbutaline has also been used in an attempt to prevent recurrent preterm labour. There is no evidence, however, that use of terbutaline to prevent preterm labour improves infant outcomes. Serious adverse events, including maternal deaths, have been reported with such use in pregnant patients.

“Women should be aware that serious and sometimes fatal side effects have been reported after prolonged use of terbutaline in pregnant women,” said Scott Monroe, MD, director of FDA’s Division of Reproductive and Urologic Products. “It is important for patients and health care professionals to consider all the potential risks and known benefits of any drug before deciding on its use.”

The FDA is aware that administration of terbutaline by injection to pregnant women is used in hospital settings in certain urgent situations. The FDA warning relates to safety concerns about the prolonged use of terbutaline injection beyond 48-72 hours, and against any use of oral terbutaline in pregnant women for prevention or treatment of preterm labour.

The decision to require a Boxed Warning and Contraindication is based on the FDA’s review of post-market safety reports of heart problems and even death associated with terbutaline use for obstetric indications, as well as data from medical literature documenting the lack of safety and effectiveness of terbutaline for preventing preterm labour, and animal data suggesting potential risks. Based on this information, the FDA concluded that the risk of serious adverse events outweighs any potential benefit to pregnant patients for either prolonged use of terbutaline injection beyond 48-72 hours or use of oral terbutaline for prevention or treatment of preterm labour.

These changes to the drug labelling are consistent with statements from the American College of Obstetricians and Gynaecologists discouraging use of terbutaline for preventing preterm labour.

There are multiple generic versions of terbutaline oral tablets and injectable formulations available. The brand name products were previously discontinued by the companies that made them.

The FDA encourages patients to talk to their health care professional if they have concerns about any treatment they are receiving. Patients and health care professionals should report any side effects from the use of terbutaline to the FDA’s MedWatch adverse event reporting programme at www.fda.gov/MedWatch1.