JACKSONVILLE, Fla. -- Two mothers who knew their sons were addicted to painkillers are speaking out about a Lake City physician who the state says prescribed large amounts of pain killers to the men in the months before they died.

A criminal investigation of Dr. Barnie Vanzant by the Columbia County Sheriff's Office was inconclusive, but the Florida Department of Health has restricted his license while they conduct their own investigation. The restriction allows Vanzant to practice, but not prescribe controlled substances.

"I got a call from my mother saying my son had overdosed," Chris Davis said.

Davis found her 31-year-old son Daniel Lewis dead in May.

The medical examiner found he died after taking a lethal amount of prescription drugs.

Columbia County detectives found that Vanzant had prescribed Lewis 1,070 Alprazolam pills, 1,040 Methadone pills, 670 Loratab pills and some muscle relaxant pills in a 114-day period.

Tammy Dennard lost her son, 25-year-old Travis Walls, in August. His death was also attributed to an overdose of prescription drugs.

"All I could do was scream; I screamed for God," Davis said. "That's all I knew how to do."

The investigation revealed Vanzant wrote prescriptions for Walls in less than one year that totaled about 1,938 Methadone pills and 996 Alprazolam pills as well as prescriptions for Loratab and Ultram.

"He was a wonderful man. He loved the Lord," Dennard said. "He knew he had an addiction and he tried to break the addiction."

"The amount they're prescribing, there's no way anyone could be productive and even live half of a normal life," Davis said.

"They're addicts. They know how to get what they want. They doctor shop; they pharmacy shop. They do what they have to do."

The Florida Department of Health last week issued an emergency order restricting the license of the family practice doctor. Among the statements of the order by state Surgeon General Ana Viamonte Ros:

"Dr. Vanzant has demonstrated a flagrant disregard for the duties and responsibilities imposed upon a physician practicing in the State of Florida and for the health and welfare of his patients. Dr. Vanzant's egregious conduct of providing to patients frequent prescriptions for controlled substances is prohibited in the practice of medicine. This conduct demonstrated by Dr. Vanzant poses an immediate serious danger to the public health, safety and welfare. This is evidence by the fact that Dr. Vanzant's actions have contributed to the death of two patients from polydrug intoxication and poisonings."

The state said the restriction will remain while they decide if Vanzant's medical license should be suspended or revoked permanently.

Vanzant's lawyer, Robert Jordan, issued a statement defending his client.

"Dr. Vanzant has served the medical needs of this community for over three decades.... He has helped many, many people over his long career.... Dr. Vanzant looks forward to a full and fair hearing on the allegations raised against him at which time he expects that his good name will be cleared."

After praying together, both mothers told Channel 4's Laura Mazzeo they had tried to get their sons help. Instead, they said their sons found a doctor who would give them an almost unlimited supply of powerful drugs.

They want others to take their loss to be a lesson.

"I just don’t want to see someone else go through this because something does have to be done," Dennard.