All three have all pleaded not guilty to charges of over prescribing drugs.
Prosecutors accuse them of conspiring to provide massive amounts of opiates and painkillers to Smith but they aren't accused of causing her death.
Frank says Stern fell to his knees and wept in the hotel room where police seized drug bottles and a duffel bag containing $8,000.
Smith's bodyguard Maurice Brighthaupt told police he was owed the money and demanded they hand it over, but they refused, Frank testified.
He tried to revive the former Playboy Playmate. He has given varying accounts of what he saw.
Brighthaupt was expected to testify Friday.
Under prosecution questioning, pharmacist Olga Kopetman identified multiple prescriptions written by Eroshevich to Anna Nicole Smith, Vicky Marshall, which is Smith's real name, and three other names including Stearn, a misspelling of Stern, from 2003 to 2006. They were filled at a pharmacy in Studio City.
Some were for the painkiller Vicodin and anti-anxiety drugs Xanax and Zoloft. Others were for sleep and anti-seizure medications, the pharmacist said.
Stern paid for the drugs, Kopetman testified, with one bill totaling $4,474.
Kopetman and another pharmacist, Emma Avakian, testified that Stern frequently picked up drugs prescribed by Eroshovich, and that they never saw Anna Nicole Smith pick up her own prescriptions, which often included large quantities of drugs with refills available.
Avakian said one prescription for Valium provided 240 pills and was refilled after just three weeks.
On Wednesday, the prosecutor painted all three defendants as conspirators who fed the celebrity's desire for prescription drugs. Prosecutors call Stern an aider and abettor.
The autopsy showed that the 39-year-old had nine different medications in her system.
Authorities claim that 44 different medications were prescribed for Smith under a number of other names, including Stern's. According to Sadow, the fake names used were to keep Smith's medical issues out of the eye of prying media.
Stern maintains he was just following the doctors' orders. Not a single hospital used her real name, including Cedars Sinai.
Meanwhile, Kapoor's lawyer said Wednesday that Kapoor's prescriptions were appropriate and worked, and "he managed her pain and he acted in good faith."
Eroshevich's attorney, Bradley Brunon, says the two women were friends and neighbors and when Smith's son died of a drug overdose, she called her friend for help.
Smith had been living in the Bahamas and was allegedly receiving deliveries of prescription medications from her doctors.
Brunon said Eroshevich rushed to bring drugs to her in the Bahamas. And that the controversial order for drugs was never meant to be given all at once. They were part of a plan to try each drug and see which one would work best.
If convicted all three defendants could face more than five years in prison and the doctors would lose their medical licenses.
The jury is made up of six women and six men. Along with the 12 jurors, five women and one man were chosen as alternates.
The Associated Press contributed to this report.