In a letter to acting FDA Commissioner Ned Sharpless, three U.S. lawmakers demanded updates on Takeda Pharmaceuticals’ recall of Natpara (parathyroid hormone), an injection used to treat a rare parathyroid disorder.

Takeda, the product’s sole manufacturer, recalled the drug on Sept. 5 due to potential issues with rubber particulates from the injector pen contaminating the medicine. The FDA approved the drug in 2015 to control calcium levels in patients with hypoparathyroidism, a disorder that affects about 70,000 individuals in the U.S.

In the letter, Sens. Patrick Leahy (D-Vt.), Bernie Sanders (I-Vt.), and Rep. Peter Welch (D-Vt.) blasted the agency for not providing patients with “any substantive information” on the recall, including how long it might last and short- and long-term solutions to resolve it. They further noted that their constituents who reached out to the agency for information have been “left confused” about when the drug will become available, and what they should do until then.