For those who live in the tabloid cross hairs, the fake name is essential. Privacy-seeking celebrities have standard pseudonyms for checking into hotels, booking spa appointments, reserving restaurant tables, advertising for help and setting up visits to the doctor's office.
But when those attempts at anonymity make their way beyond the exam room door and onto a prescription pad, a Hollywood convenience becomes a crime.
State and federal laws designed to curb prescription drug abuse make it illegal for doctors to prescribe drugs in the name of anyone but the intended user, and physicians found using pseudonyms have lost their medical licenses and faced criminal charges.
The prohibition on fake names may become a key issue in the investigation into Michael Jackson's death.
Sources close to the investigation told The Times that the performer had been prescribed drugs in the name "Omar Arnold" shortly before his death June 25.
The probe has focused on Jackson's use of drugs, and investigators are looking closely at the conduct of at least five doctors who wrote prescriptions for him.
Jackson had long used aliases in health matters, according to associates.
One person who worked closely with Jackson in the 1980s and '90s said Jackson's physicians filed his medical records under pseudonyms, including Omar Arnold, Joseph Scruz and Bill Bray, and used those names to schedule appointments and order tests.
Another longtime associate said Jackson's staff regularly picked up prescriptions for the performer under different names.
Employing false names on prescription pads is a violation of federal Drug Enforcement Administration rules and of multiple state regulations, including the Business and Professions Code and the Health and Safety Code. Health and Safety Code Section 11173 states that "no person shall make a false statement in any prescription, order, report or record."
Dr. H. Westley Clark, the director of the federal Center for Substance Abuse Treatment, said fake names flout mechanisms put in place by states and pharmacy chains to flag people potentially abusing drugs.
"It makes it difficult to track behavior of patients who might be doctor-shopping or who may be receiving large doses of controlled substances that might cause some concern," said Clark, who is licensed as both a lawyer and doctor.
Jackson's is hardly the first instance of a celebrity using false names to fill prescriptions.
When actress Winona Ryder was arrested for shoplifting in 2001, investigators found a cache of painkillers in her purse and later determined that she had used six aliases in seeking 37 prescriptions from 20 doctors.
A Brentwood cosmetic surgeon who prescribed her medication in the name of "Emily Thompson" was stripped of his medical license the following year.
When movie producer Don Simpson died from an overdose of cocaine and prescription medication in his $18-million Bel-Air mansion in 1996, investigators found a closet full of pill bottles.
Many were written to "Dan Wilson," a pseudonym.
Los Angeles County prosecutors are seeking to convict two of Anna Nicole Smith's doctors and her boyfriend on conspiracy charges for illegally providing the model with excessive amounts of narcotics and other controlled substances.
Among the evidence they have cited are prescriptions the doctors allegedly wrote for Smith in the names of her boyfriend, Howard K. Stern, and at least three other people.
All three defendants have pleaded not guilty.
An attorney for her psychiatrist, Khristine Eroshevich, has defended her use of pseudonyms, saying the physician was simply trying to protect Smith's privacy from a media scrum that had surrounded her house and rifled through her trash.
Doctors who work with celebrities say that requests to write pseudonymous prescriptions are not very common, but when they are made, privacy is normally the reason cited.
"Sometimes some of the high-profile clients I have will ask about that," said Dr. Jason Giles, a specialist in addiction medication with a private practice in Malibu.
Some of these rich and famous patients say they are worried that the details of their medical care will appear in the tabloids and hurt their reputations.
"If you're on the Wheaties box, you can't be seen to be taking drugs," Giles said. In every case, he said, he refuses to use fake names. "There are no circumstances where it's appropriate."
Dr. David Sack, whose Malibu rehab center, Promises, has treated many celebrities, said a referral to a discreet pharmacy should allay the concerns of high-profile clients. If it doesn't, he said, the request should be a red flag for substance abuse.
"There's a progression in addiction. . . . As the dosage escalates, it reaches a point where no rational physician would prescribe the quantities they are taking, and that is when they start to come in using other false identities," he said.
Dr. John F. Dombrowski, a board member of the American Society of Anesthesiologists and the American Society of Interventional Pain Physicians, said doctors can find themselves in too deep when their patients are rich, high-profile people who can "buy and sell and get what you want."
They're "basically your slave with a DEA number. This is very dangerous," he said.
Times staff writers Andrew Blankstein, Joel Rubin and Richard Winton contributed to this report.