Limbaugh's attorneys have said the prescription was labeled as being issued to his physician rather than Limbaugh for privacy purposes.
A few health officials contacted Tuesday said they never heard of such a thing.
Yet, a spokesman for the State Attorney's Office, which will review the issue, issued a caveat Tuesday. Mike Edmondson said that according to preliminary research by his office, the practice of prescribing in a third-party name may not be illegal if all parties are aware and the doctor documents it correctly.
Customs officials detained Limbaugh upon his return from a brief visit to the Dominican Republic.
A luggage search turned up a bottle of 29 of the blue pills with someone else's name on them. Limbaugh told the investigators they were for his use, according to sheriff's officials.
The law-enforcement agencies declined to provide additional details or reports Tuesday.
Pharmacy laws do not specifically address whether a doctor can write a prescription under a pseudonym, said April Brown, a doctor of pharmacy working for the Florida Pharmacy Association.
It's a practice she's never heard of, she said. Brown formerly worked at a Los Angeles hospital where several celebrities came in. "It was always their real names being used," she said.
A Department of Health spokesman said a knowledgeable investigator for the department told him he had never heard of the practice, either.