The US Food and Drug Administration (FDA) has decided to suspend the approval of Botox to treat upper limb spasticity in stroke victims pending further studies. The federal regulator wants to review more information before it approves the cosmetic drug for a new application.

Allergan markets two Botox products. Botulinum toxin type A is approved for improving facial appearance. And the other Botox product is approved to treat spasm of eyelids, severe neck muscle spasms, and excess sweating.    

Last February, the FDA launched a safety review of Botox and Botox Cosmetic. The FDA said that there had been several confirmed cases of adverse patient reactions to the drug. Some of the cases resulted in hospitalization and death. These cases mostly occurred on children treated for cerebral palsy and limb spasticity. The FDA highlighted that these cases may have been routed from overdosing.

Last month, the agency announced that both Botox products would carry a Black Box warning regarding the risk of adverse effects if the cosmetic drug’s effect spreads beyond the site where it was injected. In addition to that, the FDA is also requiring manufacturers to develop and implement a Risk Evaluation and Mitigation Strategy (REMS) plan to provide more information on Botox products that cannot be interchanged. REMS will also include a Medication Guide that explains the risks to patients, their families, and caregivers.

According to Reuters, the FDA wanted to review Allergan’s proposed REMS for Botox before making a decision on expanding the drug’s applications. The regulator also proposed some label revisions, including one that could broaden Botox use to upper limb spasticity regardless of underlying causes. 

The FDA is not requiring that Allergan to conduct additional clinical trials for the new applications of Botox. The manufacturer says that it will comply with the FDA’s request within 60 to 90 days.