The asthma drug terbutaline should not be used to prevent or treat preterm labor, according to an alert issued by the U.S. Food & Drug Administration (FDA) yesterday. Not only is this off-label use of terbutaline ineffective, the FDA said, women treated with the tablets form of the drug, or those who undergo prolonged treatment with trebutaline injection may be at risk for heart problems and death.
According to the FDA notice, the agency is also requiring the addition of a Boxed Warning and Contraindication to the terbutaline prescribing information (labeling) to warn against these uses.
Terbutaline is FDA-approved to prevent and treat narrowing of the airways (bronchospasm) associated with asthma, bronchitis, and emphysema. 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.
Terbutaline is often used off-label for obstetric purposes, including treating preterm labor and treating uterine hyperstimulation. Terbutaline has also been used in an attempt to prevent recurrent preterm labor. There is no evidence, however, that use of terbutaline to prevent preterm labor improves infant outcomes, the FDA said. Serious adverse events, including maternal deaths, have been reported with such use in pregnant patients.
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 labor.
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 labor, 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 labor.
