Drug is often used as the past tense of drag, as in the following example:
Example: I drug myself out of bed this morning.
The past tense of drag is actually dragged, not drug. This error is particularly common in speech. Even Bill Clinton once made this blunder on national television, returning to bad habits he developed as a youth growing up in Arkansas.
Remember that the word drug should never be associated with any kind of pulling action. It should only be used when referring to some type of medicinal substance.