DETROIT — Medical marijuana cannot be sold through private shops, the Michigan appeals court said Wednesday in a major decision that strikes at businesses trying to cash in on pot and cuts off a source for people with chronic ailments.

A three-judge panel said the 2008 medical marijuana law, as well as the state’s public health code, does not allow people to sell pot to each other, even if they’re among the 99,500 who have state-issued marijuana cards.

The court said Compassionate Apothecary in Mount Pleasant, Mich., can be immediately shut down as a “public nuisance.” The 3-0 decision means local authorities can pursue similar businesses, estimated at 200 to 300, in their communities.

It was not immediately clear whether they would, but state Attorney General Bill Schuette said he’s notifying all 83 county prosecutors.

“This ruling is a huge victory for public safety and Michigan communities struggling with an invasion of pot shops near their schools, homes and churches,” Schuette said in a statement. “The court echoed the concerns of law enforcement, clarifying that this law is narrowly focused to help the seriously ill, not the creation of a marijuana free-for-all.”

Of course, not everyone shares that view. Chuck Ream, president of an Ann Arbor shop, called the ruling an “assault on democracy” nearly three years after voters approved marijuana as a way to relieve pain or other medical problems. He estimates that one-third of people with marijuana cards get pot through dispensaries, with others growing their own or getting it through a registered caregiver.

“If they want wheelchairs chained to every door at the Capitol, if they want to fight about this — oh, boy, they’ll have a fight,” said Ream of A2 Compassionate Healthcare. “There are a lot of people who don’t want to be drooling idiots on Oxycontin. They’ve found a medicine that relieves their pain and makes them happy.”

There is no dispute that the marijuana law makes no mention of dispensaries; it doesn’t even indicate how people should get their dope. It says people can possess up to 2.5 ounces of “usable” pot and keep up to 12 plants in a locked place. A caregiver also can provide marijuana.

Compassionate Apothecary, and owners of the mid-Michigan company, claimed they weren’t doing anything illegal because the law allows the “delivery” and “transfer” of marijuana. The business allows its 345 members to sell marijuana to each other, with the owners taking as much as a 20 percent cut. In less than three months, Compassionate Apothecary earned $21,000 before expenses after opening in May 2010.

“The ‘medical use’ of marijuana does not include patient-to-patient ‘sales’ of marijuana. Defendants, therefore, have no authority under the (law) to operate a marijuana dispensary that actively engages in and carries out patient-to-patient sales,” said appeals court judges Joel Hoekstra, Christopher Murray and Cynthia Diane Stephens.

Compassionate Apothecary attorney John Lewis said the shop was still in business Wednesday but likely not for long.

“It’s unfortunate for patients who benefit from medical marijuana. It’s going to affect their access to an uninterrupted supply,” Lewis said.

Ricky Lewis, 53, of Southgate said he’s relied on a Detroit-area dispensary to ease symptoms of glaucoma. He said he can’t afford to grow marijuana because lights add $300 to $400 to his monthly electricity bill.

When people are compelled to buy marijuana on the street, “you may not get what you need; you may get robbed,” said Lewis, no relation to the attorney.

Corrina Neff, a board member with the nonprofit Weidman Compassion Club in Isabella County, said the phone was ringing nonstop Wednesday from people “freaking out, panicking, wondering where they’re supposed to get their meds from.”

“We’re going to do everything we can to comply with the law, but I just can’t say no to people who are really suffering,” Neff said. “So I’m probably just going to give it to them for free and I’ll have to offset my costs somewhere else.”

Just this week, an ordinance took effect in Ann Arbor, a liberal college town, to license dispensaries. Many already operate there.

“How this works will have to be reviewed” because of the court ruling, city attorney Stephen Postema said.

Nick Tennant, who advises marijuana users at a Detroit-area trade school called Med Grow Cannabis College, said he wasn’t surprised by the decision. Opening a shop, he said, was “extremely risky.”

“Our law gives no specific guidelines to the operation of dispensaries — nothing. Other states do. Look at Colorado,” Tennant said.

Indeed, medical marijuana is more than 10 years old in Colorado. On July 1, dozens of rules took effect there allowing and regulating the sale of pot at commercial businesses. Sixteen states and the District of Columbia allow the medical use of marijuana.

It was the first time the Michigan appeals court has ruled in a case involving medical pot sales. The state Supreme Court, meanwhile, has agreed to hear appeals on other aspects of the medical marijuana law.

“This law was poorly crafted, poorly written, and there have been some unintended consequences,” Schuette, the attorney general, told The Associated Press.