DENVER—A handful of doctors are writing almost all of Colorado’s referrals for medical marijuana, and state health authorities are asking for new guidelines for how doctors can refer patients for pot use.

As of Monday, a total of 820 licensed physicians had authorized medical marijuana for 15,800 patients.

But just 15 doctors account for 73 percent of all the state’s marijuana patients, the Colorado Department of Public Health and Environment said. And just five doctors authorized 49 percent of all recommendations, the department said.

But because of medical confidentiality laws, the health department is barred from turning over those doctor names to law enforcement.

Instead, the department is asking state lawmakers to write rules clarifying when doctors can refer patients to marijuana. That would make it easier for state health authorities to bring suspect doctors to the state Board of Medical Examiners.

The changes include a rule that doctors and medical marijuana patients must have an “ongoing” relationship and that the doctors can’t take payments from medical marijuana dispensaries. Current law says only that referring doctors must be in good standing.

Department spokesman Mark Salley said health authorities aren’t seeking to share doctor names with police. They are simply seeking better guidance before referring doctors to the review board.

The proposal would not change the list of maladies that make patients eligible for medical marijuana. Qualifying ailments include seizures, multiple sclerosis, glaucoma, HIV and “chronic pain,” a condition some say is too vague.

Doctors can’t write “prescriptions” for pot, because marijuana remains illegal under federal drug laws and can’t be provided by a pharmacy. Instead, doctors can “refer” patients to a state-certified caregiver to provide marijuana. Patients who don’t want to pay a dispensary are allowed to grow small amounts of marijuana for personal consumption.

The fact that so few doctors are writing hundreds of referrals has state officials wondering whether the state’s marijuana rules are being misapplied.

Colorado Chief Medical Officer Ned Calonge said officials are suspicious of whether the doctors writing hundreds of referrals have true relationships with the people they’re referring.

Calonge said in a statement that the proposed regulations “parallel federal laws designed to provide protection from economic conflicts of interest that may arise when a physician stands to benefit directly from the sale of a medication or service that he or she prescribes.”

Last month, Peter W.S. Grigg of Colorado Springs became the state’s first doctor convicted of selling a recommendation for a medical marijuana registry certificate.

Grigg met an undercover police officer in a Wal-Mart parking lot last year and sold him a marijuana referral for $300, even though the officer said on tape he had no medical condition qualifying him for marijuana.

Grigg told the officer he had written about 200 referrals. It wasn’t clear Thursday whether he was one of the “handful” of doctors mentioned by the health department.

Grigg pleaded guilty to attempting to influence a public servant and was sentenced to five years probation. Grigg also voluntarily surrendered his license to practice medicine in Colorado.

———

On the Net:

— Colorado’s marijuana rules:

http://www.cdphe.state.co.us/hs/medicalmarijuana/AdoptedRules0200900360.pdf