The drug-testing provision, its sponsors said, is an inducement that bubbled up in the course of a freewheeling focus group of voters testing arguments that could persuade people to support a higher damage ceiling in malpractice lawsuits. The enthusiasm voiced in the focus group, strategists for the campaign said, suggested that the clearly popular idea could overcome medical industry advertisements warning that raising malpractice award limits would push up insurance rates and costs to local government.

Under Proposition 46, the ceiling for pain and suffering awards in medical negligence suits, set at $250,000 by the State Legislature in 1975, would be raised to $1.1 million to reflect inflation. The results of random drug tests on doctors would be reported to the California Medical Board; hospitals would be required to report the names of doctors suspected of abusing drugs or alcohol. Doctors would also be required to consult state prescription databases before prescribing controlled substances to patients, to guard against “doctor shopping.” Doctors predicted that voters would see through what they called political trickery. Dr. Richard Thorp, the president of the California Medical Association, described the measure as a “money grab by trial lawyers.” He added, “The decision about drug and alcohol testing shouldn’t be made by political consultants — it should be made by stakeholders in a careful, thoughtful way.”

Asked if California doctors could support drug testing in any form, Dr. Thorp said: “That’s a great theoretical question. But we’re not dealing with a theoretical initiative. We are dealing with this state initiative. We cannot pass this initiative as it is written today. It is a flawed, deceptive ballot initiative, with one goal in mind: to increase money for trial lawyers.”

Still, the measure threatens to put the medical profession in the difficult position of having to argue against the kind of scrutiny that an increasing number of workers — particularly in jobs affecting the public well-being — routinely undergo. Backers of Proposition 46 have begun putting out a steady stream of news releases about cases involving doctors with a history of drug and alcohol abuse. “It’s crucial: I can’t believe we haven’t done this already,” said Arthur L. Caplan, a medical ethicist at New York University. “We can argue about how often that is, and what to do if you are positive. But the idea that we wouldn’t be screening our surgeon, our anesthesiologist or our oncologist when we are going to screen our bus drivers and our airline pilots strikes me as ethically indefensible.”