Ira Freeman said he received a request for painkillers, muscle relaxants and sedatives on Sept. 15, 2006, four days after Smith's son died, the Los Angeles Times reports. He declined to fill the prescription.
"If she got ahold of these medications, it could have fatal consequences," he told a judge in Los Angeles.
Smith died five months later of an overdose.
'Out of Her League'The testimony was part of a preliminary hearing to determine whether the psychiatrist, Khristine Eroshevich, Smith's boyfriend, Howard K. Stern, and another doctor should stand trial on felony charges of conspiring to give dangerous drugs to an addict through fraudulent means.
Freeman said the Sept. 15 prescription called for eight times the recommended dosage of a hypnotic sedative called Dalmane, and that Eroshevich seemed unfamiliar with the medications she was ordering.
He recounted talking to a toxicologist, who said of Eroshevich: "She is way out of her league on this."
The hearing follows a two-year investigation into Smith's death, which an autopsy revealed was caused by an acute combination of toxic drugs, especially chloral hydrate, Benadryl, clonazepam, diazepam and lorazepam.
Earlier this week, another psychiatrist testified that Smith tried to quit prescription drugs in 2006, when pregnant with her daughter, but failed to do so.