DENVER (CBS4) – A Denver family physician has been prescribing a controversial medication to his patients, sick with coronavirus, and believes it is yielding positive results. Dr. Constantine Tsamasfyros, who has been a primary care doctor in Denver for nearly 50 years, told CBS4 Investigator Brian Maass he has prescribed a combination of hydroxychloroquine (also known as Plaquenil) and an antibiotic called azithromycin to about a dozen patients over the last few weeks.

“They all did well. They seemed to reverse their symptoms in a day or two,” said Tsamasfyros, who said he “absolutely” believed the medication was working.

“If they’re drowning, you either pull them out of the water or at least throw them a rope to come out,” he said while explaining his decision to prescribe the medication.

Although hydroxychloroquine has been promoted by President Donald Trump, who called it a “game changer,” other medical experts are far more cautious, warning against its potentially deadly side effects and limited research on its effectiveness against COVID-19.

The medication has been used for years to treat malaria, lupus and rheumatoid arthritis. But in March, a French researcher in Marseilles, Dr. Didier Raoult, claimed he had successfully treated COVID-19 patients with hydroxychloroquine.

He claimed 40 coronavirus patients were treated with hydroxychloroquine, and more than half had positive results. President Trump called that potentially “one of the biggest game changers in the history of medicine.”

However Trump’s top infectious disease advisor, Dr. Anthony Fauci, said there was only “anecdotal evidence” that the drugs might work.

Other researchers and doctors have expressed skepticism over the methodology of the French study noting a lack of controls and checks and balances. The drug can also have significant side effects and can cause fatal heart problems.

Tsamasfyros said he began prescribing it to patients with coronavirus symptoms three to four weeks ago, since there was nothing else available.

“On an outpatient basis there is really nothing to offer our patients,” he said. ”Until we have something documented or better this is a fallback and we should not be depriving our patients. You certainly don’t want to deprive a patient that might be drowning in an inflamed lung situation of any kind of help or assistance.”

Tsamasfyros, known to his patients as “Dr. Sam,” said he knew what he was doing was highly controversial and he was aware of the flaws in recent studies. But he said the medications made sense to him on a scientific level and through his “common sense.”

He told CBS4 he advises patients of the potential side effects.

Dr. Comilla Sasson, a Denver area emergency doctor, said “Uncontrolled, unblinded ‘trials’ are not research or proof of therapeutic effectiveness. We have to stop the madness,” she wrote. “We are taking this drug away from patients where there is a proven benefit.”

She was referring to lupus patients and other patients who rely on hydroxychloroquine/plaquenil, but are now having trouble finding it as other people worried about coronavirus have been stockpiling the medication.

Tsamasfyros told CBS4 he had four other doctors ask him to write prescriptions for them for the medication, as they feared they might contract coronavirus.

He said he was concerned he too might contract the virus through his medical practice, so obtained doses of it for himself, his wife and son.

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”But on the front line I could come down with it, and at my age especially and I need to have it available to me if that happens.”

Asked if he planned to continue prescribing it to patients exhibiting signs of coronavirus, Tsamasfyros said, ”absolutely.”