On February 17, 2011, The US Food and Drug Administration issued warnings to the public stating that injectable Terbutaline, a potent bronchodilator indicated for the treatment of acute airway narrowing, should not be used for the long term prevention of preterm labor. The FDA now recommends that Terbutaline be used (if at all for this off label purpose) for no more than 48-72 hours because of its potential to cause maternal cardiac arrhythmias (irregular and potentially deadly heart rhythms). Likewise, the FDA warns against using oral Terbutaline because it has not been shown to be efficacious in preventing preterm labor and has similar safety concerns as the injectable form. The FDA requires that all forms of Terbutaline (oral, injectable and subcutaneous pump) carry Black Box warnings and contraindications for use. The decision to require the addition of a Boxed Warning and Contraindication is based on new safety information received and reviewed by the FDA.
Terbutaline was first indicated and used for the treatment of acute bronchospasm for respiratory conditions such as asthma, bronchitis and emphysema in 1976. Terbutaline belongs to a class of drugs called Beta Adrenergic Receptor Agonists. The anticholinergic properties of the drug can cause dangerous and potentially lethal heart arrhythmias. As indicated for bronchospasm, typically once the acute airway narrowing has been reversed, Terbutaline is stopped and patients are switched to maintenance medications. Terbutaline was never intended for long term use.
Terbutaline became popular for the treatment of preterm labor in the late 1990′s when some cases of preterm labor appeared to respond to the drug. However, Terbutaline has not been efficacious across the board and studies of the drug in injectable, oral and even continuous infusion have shown no efficacy. Terbutaline, a vasoconstrictor, was thought to slow and subsequently halt contractions. However, no matter what the “supposed” effect, there is no medical evidence that Terbutaline, whether injected or taken orally, does anything to halt preterm labor. In 2008, The FDA issued a “Dear Colleague” response to a citizen’s petition, yet it is still being used for the treatment of preterm labor despite its potential for serious and even fatal cardiac complications. To date, 16 maternal deaths can be attributed to cardiac arrest as a result of Terbutaline administration.
It’s amazing to see that with all of the current data, some even amassed by the FDA itself, The FDA still has not come out and issued a complete halt to the use of Terbutaline as a tocolytic treatment for preterm labor. Why is this? With the known side effects, the fact that it is used off label and with the lack of evidence-based medicine to back it up, why hasn’t the FDA made the clear statement, “Do Not use Terbutaline in any form as a treatment for preterm labor?”
Perhaps the FDA feels that by prohibiting the use of Terbutaline, they will be reducing the number of treatments available for obstetricians to use with cases of preterm labor. But if this treatment has no evidence that it is efficacious, I fail to see the loss. We all know that treating women with preterm labor is tricky and the truth of the matter is that there are very few reliable, effective treatments. But the answer is not to continue using treatments without evidence of benefit yet with serious, potentially fatal side effects.
If the FDA, obstetricians and others are truly concerned that there aren’t enough efficacious treatments available for preventing preterm labor, I believe that their efforts would be better spent canvassing for support and funding for research for effective treatments rather than trying to make a clearly inappropriate treatment suitable. How many more women (and perhaps babies) will have to lose their lives to Terbutaline treatment before we begin to look elsewhere for treatments for preterm labor?