A few times a week, Anthony DiPasquale said, he filled his car with recruits for the trip from Port Richmond to the doctor's office in Willow Grove.

DiPasquale didn't know their medical histories, or sometimes even their names. But he gave each $200 and talking points - descriptions of their pain, the inability to bend over - and they walked out with the payoff, prescriptions for oxycodone pills he could sell on the street at 10 times their value.

The doctor, Norman Werther, grew so busy that DiPasquale sometimes got there before the office opened to beat the rush.

"It was a madhouse," he told a jury Tuesday.

DiPasquale was the first in a parade of street dealers expected to testify as prosecutors in Philadelphia opened the trial against Werther, a 73-year-old Horsham doctor who they say ran one of the most egregious pill mills they had seen.

Between 2009 and his arrest in 2011, Werther allegedly furnished hundreds of thousands of pills to six drug networks. His once-struggling practice exploded, Assistant U.S. Attorney Nancy Beam Winter told jurors. His annual income - fueled by the $150 fee he charged for every visit - jumped from $50,000 to more than $1 million so quickly that he began laundering it through different bank accounts, Winter said.

She said Werther, in financial straits, cast aside his oath and became no different from thugs who feed addictions on city corners.

"Drug dealers come in all shapes and sizes," Winter said.

The trial, before U.S. District Judge Berle M. Schiller, highlights what experts call an epidemic in prescription drug abuse.

Werther's arrest and indictment on drug conspiracy and laundering charges followed a U.S. Drug Enforcement Administration probe that included thousands of hours of secretly recorded calls and video captured by a camera hidden on a utility pole outside the office door.

More than 60 people were charged, and all but a few have pleaded guilty. That left Werther, a slight, balding, bespectacled man who spent three decades in an Abington-area family practice, sharing the defense table Tuesday with Angel Duprey, an alleged drug dealer half his age with a steely glare, a criminal record, and tattoos wrapped around his neck and cheek.

Also on trial is Troy Brinkley, who, like Duprey and DiPasquale, is accused of running a separate drug network supplied by Werther.

Werther's lawyer conceded that some prescriptions ended up in the wrong hands, but insisted that Werther was a victim of the conspiracy, not an organizer of it.

David M. Laigaie said Werther unknowingly inherited the dealers as patients when he bought what was a pain-management practice from a Philadelphia orthopedic surgeon in 2008. The traffickers coached patients on what to tell Werther, "co-opted" members of his staff, and enlisted them to create false records, he said.

"The groups and their patients went to great lengths to deceive Dr. Werther," he said.

Duprey's lawyer, David Zellis, urged jurors to look critically at the case. Brinkley's attorney, Lawrence Krasner, said the evidence against his client amounts to innocuous bank records and testimony from "people who have spent their lives lying."

A key witness will be a former member of one of the drug rings who tipped off DEA agents in 2010. The woman later gathered evidence inside the office by wearing recording devices during visits with Werther, testified John Hipple, a police officer from North Coventry Township police officer in Chester County who is assigned to the DEA.

Winter, the prosecutor, acknowledged that the informant was well-paid - court records show she received $193,000 for her cooperation on the case - but said most of the money came as an award because the witness helped agents recover millions of dollars.

Winter also promised jurors the equivalent of a smoking gun - a note Werther's wife wrote to the staff in 2011 warning them to turn away patients from the dealers because agents were closing in.

The prosecutor said jurors would also hear that Werther distributed drugs outside acceptable practices by prescribing oxycodone for a patient who came to him seeking help to break an addiction to the drug. The patient, Nathaniel Backes, died in September 2010 from an overdose of oxycodone and cocaine.

"When you're involved in the illegal drug market, that's what happens: Someone dies," Winter said.

If convicted of the major charges, Werther faces at least 20 years in prison. The trial is expected to last three weeks.

Contact John P. Martin at 215-925-2649, at jmartin@phillynews.com or @JPMartinInky on Twitter.