The fact any person charged with violating this section is or has been legally entitled to use alcohol or other drugs or substances is not a defense against any charge for violating this section. It is an affirmative defense that a drug was used only as directed or cautioned by a practitioner who legally prescribed or dispensed the drug to that person. If the individual violated subdivisions a, b, c, or d of this subsection and subdivision e of this subsection and the violations arose from the same incident, for purposes of suspension or revocation of an operator's license, the violations are deemed a single violation and the court shall forward to the department of transportation only the conviction for driving under the influence or actual physical control.
N.D.C.C. § 39-08-01