[khanar]

A friend is telling me it's not OK to ask the patient
"Do you use Illicit Drugs?"

What should I be asking then

 

[lee-usmle]

Use the word recreational

The word Illicit may sound judgmental i.e. you are judging the patient bad as he's taking something illicit.
Here's the dictionary's defintion of the word illicit:
contrary to accepted morality (especially sexual morality) or convention; "an illicit association with his secretary"

Therefore I suggest you use the word "Recreational"
So ask the SP
"Do you use recreational drugs?"