Let's take a look at what Mr. Limbaugh was really up to.
According to police records of his prescriptions, El Rushbo was dropping about 10 of the highest-strength hydrocodone (e.g., Norco, Oxycontin) tablets available. Each pill that he was taking was 4 times the strength of what's typically prescribed. He was taking more twice the maximum prescribed dosage each day - and this is the heaviest duty stuff available - it's used for the worst pain imaginable.
So, in short, he was taking a dosage that no legitimate physician would ever prescribe.