"The U.S. Supreme Court decision this morning is the death knell to the medical marijuana issue," he said, a sentiment shared by some medical marijuana advocates.

"I would advise all physicians and anyone who is involved in distributing or helping in the distribution of any illegal narcotic to be very, very leery," he said.

'Aina Haina optometrist Joyce Cassen, one of 116 doctors who issued certificates to Hawai'i's 2,596 registered medical marijuana users, turned down about a half dozen requests, but granted one for a patient for his glaucoma. She said the marijuana helped the eye pressure and had a "definite medical benefit."

But she won't be issuing any more.

"If it could become something I could be prosecuted for, I certainly would want to stay away from that," she said.

The 6-3 decision by the high court did not strike down the laws authorizing medical marijuana use in Hawai'i and 10 other states, but essentially cleared the way for federal marijuana prosecution despite the states' laws.

The possible end of the program worries patients like Rhonda Robison, who fears she will not be able to get marijuana for her 34-year-old battle against muscular dystrophy, which she called "very, very painful."

Robison said she is struck when she least expects it. The muscles in her body contract and expand throughout the day. Her joints, she said, also often slip out of place, causing sharp pain.

But she said it improved in 2000, when Hawai'i became the eighth state to allow marijuana use for medical purposes.

Robison's husband, John, 39, who has undergone chemotherapy for leukemia, also has a permit to use marijuana.

Kubo said he doesn't think medical marijuana smokers "have anything to fear as far as federal prosecution is concerned." Under federal law, possession of the amounts allowed by the state medical marijuana law would be a misdemeanor punishable by up to a year in jail.

Kubo said traditionally, those cases are turned over to state and county authorities for their review. But he said an accomplice in the distribution of marijuana can be held criminally liable under federal law. The first offense in most cases would be a misdemeanor, but he cautioned that a second offense carries mandatory jail time.

As to whether he plans to launch any prosecutions, Kubo said he will need to consult with the U.S. Justice Department as well as the state attorney general and city and county prosecutors.

Hawai'i adopted its medical marijuana law five years ago. It allows the use of marijuana for "debilitating" medical conditions that include cancer, glaucoma, HIV, severe pain and nausea. But the law requires approval by a doctor who certifies the use of the marijuana for the condition.

"I don't think I could be counseling anyone to continue their marijuana use, especially if it's a federal crime," federal Public Defender Peter Wolff said.

He also suggested that the decision "puts in jeopardy" medical doctors who might also risk their medical licenses for assisting in the violation of federal law.

"I think the Hawai'i program is essentially dead, unless doctors are willing to take a huge risk to their ability to practice medicine, and why would they do that?" he said.

Bill Wenner, a retired Big Island surgeon and one of the pioneers in issuing certifications, agreed that the decision will kill Hawai'i's program.

He said not many doctors were willing to participate when the program first started. If the decision means the federal prosecutors can prosecute people using marijuana for medicinal purposes, "it's open season for patients and it's not hard to figure it's going to be open season on doctors, too."

Jeanne Ohta, executive director of the Drug Policy Forum of Hawai'i, which favors drug treatment over prison, said the decision does not change the Hawai'i law. But she had hoped that the Bush administration would not "waste your tax dollars" by prosecuting the patients.

"There are other issues to expend money on," she said.

Tom Mountain, 51, founder and director of the Honolulu Medical Marijuana Patients Cooperative, which assists medical marijuana patients, said the prosecution of the doctors would shut down his operation. He said the patients would be forced to pay for expensive medicines or get the marijuana, which sells on the street for about $600 to $700 an ounce. State officials said Hawai'i's program will continue operating as they await word from Attorney General Mark Bennett.

Bennett said he didn't think the decision would have much of an effect because the federal government had the authority in the past to prosecute marijuana users or doctors acting under state medical marijuana laws, but didn't do so.

But he said if the Justice Department decides to prosecute the doctors, it will have a "large practical consequence."

"I think we need to see whether the Department of Justice makes any kind of material change," he said.