An Alton doctor accused of operating a pill mill even after receiving reports that several of his patients had overdosed on prescription drugs pleaded not guilty Tuesday in federal court in East St. Louis.

Dr. Viwathna Bhuthimethee, 66, was released on a $50,000 unsecured bond following his arraignment on 15 felony charges. He faces one count of health care fraud, eight counts of illegally prescribing the painkiller hydrocodone and six counts of illegally prescribing the anti-anxiety drug Xanax.

The fraud and hydrocodone charges each carry maximum prison sentences of 10 years in prison, while the Xanax charges carry up to five-year sentences.

Bhuthimethee and his Edwardsville-based attorney Christopher Threlkeld declined to comment on the case.

Bhuthimethee, who was dressed casually in a short-sleeve striped shirt and slacks, calmly answered "Yes, sir, I do," when federal Magistrate Judge Clifford Proud asked him whether he understood the charges and the penalties.

A grand jury indicted Bhuthimethee on July 19 following a joint federal and local investigation that began in 2008 and involved the U.S. Drug Enforcement Administration, Alton Police, the Madison County Coroner's office, among several other state and federal agencies.

The drug charges list four patients who allegedly were prescribed narcotics without a legitimate medical purpose. But prosecutors are alleging a wider scheme involving the prescribing of drugs to chronic pain patients whose underlying problems he did not treat.

They claim Bhuthimethee ran a high-volume business at his walk-in clinic at 654 E. Broadway St., where he would see dozens of patients a day, the vast majority of whom would be prescribed narcotics. He allegedly prescribed drugs in a way that was likely to cause dependence and combinations of drugs that were known to have heroin-like effects.

"For most patients, Bhuthimethee did not operate a legitimate medical practice, but instead was engaged in a scheme to distribute and dispense controlled substances illegally, thereby defrauding Health Care Benefit Programs and patients of money by running what was, in essence, a prescription service for drug addicts, commonly known as a 'Pill Mill,'" the indictment states.

The indictment alleges Bhuthimethee indiscriminately prescribed narcotics in excessive amounts even when patients showed obvious signs of drug abuse.

"Despite having over time notice of the overdoses and deaths from several sources, including the Madison County Coroner's Office, hospitals, and family members of the deceased, Viwathna Bhuthimethee failed to change his prescribing practices, with a consequence of such failure being continuing overdoses," the indictment states.

Nine of Bhuthimethee's patients died of drug overdoses between 2006 and 2010, court documents state.

The oldest victim was 55 and the youngest victim was Bobbie Jo Sanders, who died in December 2006 at age 20 of a hydrocodone overdose. Sanders left behind a young daughter whose grandparents are suing Bhuthimethee for wrongful death on her behalf.

Their lawyer, Amy Meyer, said her clients are pleased the doctor is being prosecuted.

"I feel that his role in this rises to the level of a drug dealer," Meyer said. "It's especially egregious in light of the fact that he took an oath to do no harm."

U.S. Attorney's office spokesman James Porter said the federal version of the drug-induced homicide, which carries a sentence of 20 years to life in prison, did not apply in Bhuthimethee's case because he was a doctor licensed to prescribe narcotics. Prosecutors plan, however, to ask the judge to take into account the overdoses at sentencing, he said.

Prosecutors alleged Bhuthimethee made hundreds of thousands of dollars a year off his patients by requiring them to make monthly visits in order to fill their prescriptions and to pay $55 to $60 in cash for each visit.

In the process, the doctor also defrauded Illinois Medicaid, court documents state. He refused to accept Medicaid payments for most office visits, though he was a Medicaid provider and was aware that the patients were using the public health care system to pay for the fraudulent prescriptions, the indictment alleges.

"Patients who went to the Walk In Clinic have described an overwhelming and chaotic environment," court documents state. "... One patient reported waiting 14 hours to see Bhuthimethee the day he returned from vacation. Some patients farther back in line would try to buy their way to the front of the line. Also some patients in line would buy and sell controlled substances to other patients while they waited in line."

Bhuthimethee voluntarily surrendered his DEA license to prescribe narcotics in July 2010 under pressure from federal investigators. He still has his medical license, but the Illinois Department of Financial and Professional Regulation filed a complaint against him in December that is pending.

His clinic has since closed. He said he retired in February.

While out on bond, Bhuthimethee will be allowed to travel within the continental United States in order to visit his children in Washington, North Carolina and California, though he was forced to give up his passport.

Bhuthimethee was asked about his background during a deposition he gave in December in connection with a civil lawsuit involving another doctor sued by Sanders' family.

Bhuthimethee is originally from Thailand, where he graduated from Chulalongkorn University's medical school in Bangkok. He immigrated to the United States in 1970.

The doctor trained at several hospitals in the New York City area and was board certified. He opened his Broadway Street clinic in 1992.

He acknowledged the federal investigation under questioning from Meyer. He said the investigators brought to him three cases of patients who died of overdoses. He told her a couple of the victims had drank alcohol and may have abused other medications.

"I usually only give one thing, hydrocodone," Bhuthimethee said. "It is the most common. What we use is a limited amount. It just happened that that they die and they were on that medication."

Bhuthimethee was featured in a News-Democrat series published Sept. 18 detailing the rising number of overdose deaths in the metro-east, especially among chronic pain patients who had been addicted to prescription drugs.

Bhuthimethee's trial is scheduled for Oct. 15 before Chief Judge David Herndon.

Contact reporter Kevin Bersett at kbersett@bnd.com or 239-2535. Follow him on Twitter at twitter.com/KevinBersett