Shackelford was trained in internal medicine at Harvard. He currently oversees recovery, treatment and rehabilitation of patients dealing with personal injuries, including car crash.
Shackelford recently decided to start recommending medical marijuana as a course of treatment for patients in his practice.
"Cannabis has been used therapeutically by humans for probably 6,000 years of recorded history, and used quite successfully," Shackelford said.
As of December, the Colorado Department of Public Health and Environment (CDPHE) reported 820 physicians recommend medical marijuana. As of February, The CDPHE reported 63,000 people have submitted applications to be medical marijuana patients.
Dr. Shackelford would not tell 9NEWS how many recommendations he has given out, other than to say, "the total number of patients I've evaluated for medical marijuana is estimated to be less than 20 percent of the patients I've seen in the last year.
"I found a number of patients who had reached the end of their treatment and were not really able to continue taking high dose narcotics but had no other fall back," Shackelford said. "I found that the research and the clinical experience of patients with Cannabis as medicine was overwhelmingly positive, found it was a useful thing for them."
Colorado voters approved Amendment 20 in 2000. It says medical marijuana can be used by people suffering from debilitating medical conditions, including cancer, glaucoma, HIV/AIDS and severe pain, among other conditions.
Shackelford says he screens his patients carefully and examines them thoroughly before writing a marijuana recommendation and he will not always recommend marijuana as a treatment.
"It's not different, really, in any way from the time I spend with patients in any other setting in the rehabilitation practice or nutrition support," he said.
The Colorado Medical Society is the largest association of physicians in the state. The president of the group, Dr. Mark Laitos, says the group supports recommending cannabis to patients, as long as doctors use proper procedures.
"A physician who assesses their patient and applies their skill to come up with a decision about the right diagnosis and the right treatment and then applies that to a treatment that is legal and for which the benefit outweighs the downside for the patient - we think that's good for a doctor to do that," he said.
Shackelford believes more doctors will start recommending medical marijuana in the future.
"Marijuana has its place in medicine, either as a primary treatment or an adjunctive treatment," he said. "It is ultimately about the patients whom we serve. If a prescription drug is more appropriate treatment, that's what we should do. If marijuana is more appropriate for that patient, that's what we should recommend."
According to the CDPHE, of the 820 doctors who write medical marijuana recommendations, only about a dozen write the bulk of them. In a news release, the agency cited a "concern" about whether some doctors were really following the doctor-patient procedure.
There are two bills going through the legislature that would set new standards for the doctor-patient relationship.
For more information, visit: http://www.cdphe.state.co.us/release/2009/121709.html.
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