A bill to suspend licenses for physicians accused of overprescribing medication has passed the California Legislature, but supporters aren’t happy.

Senate Bill 670, authored by Sen. President Pro Tem Darrell Steinberg, would have temporarily restricted doctors who are accused of harming patients by improperly prescribing medicine. But last-minute changes to the proposal stripped out that provision after a flurry of lobbying from the California Medical Association.

Steinberg staffers said the bill had to be changed to pass the Legislature. But supporters believe the bill would have gone a long way to ensuring patient safety. Carmen Balber, executive director for an advocacy group called Consumer Watchdog, said Steinberg’s original proposal would have focused attention on dangerous doctors that jeopardize public safety. She referred to a Los Angeles Times investigation last fall that cast suspicion on 71 Southern California doctors who each prescribed medicine to multiple patients that later died from taking those drugs.

“The reason this proposal was so important was because it gave the board the power to pull, not a doctor’s whole license, but their ability to prescribe medicine that’s causing the most harm to patients until an investigation is conducted,” said Balber.

But Molly Weedn, a spokesman for the California Medical Association, said the state’s medical board already has plenty of power to restrict doctors suspected of impropriety. Steinberg’s bill would have punished doctors before finding them guilty, she said, while having a chilling effect on a physician’s practice.

“You’re talking about interrupting continuity of care for the patients and their doctors on the lowest standard of cause,” Weedn said.

The medical association now supports the bill with the prescription provisions removed. But Balber said her group may introduce a ballot measure next year that puts the issue before voters.