The generic drug became a variable in a treatment plan with no room for error. “If we’re giving a patient inert medication,” that is, medication that doesn’t work, “it’s a huge failure of the system,” said Starling. “An organ has been wasted potentially,” and so has money: The average cost of transplanting a heart is well over $1 million.

Over the next six months, the physician worked with his staff to make sure that none of their patients was taking the Dr. Reddy’s tacrolimus and that the hospital’s inpatient and outpatient pharmacies no longer carried it. But he couldn’t control what his patients took once they left the clinic’s grounds.

Soon enough, his worst fears were realized.