Nev. Rev. Stat. § 453.348
In any proceeding brought under NRS 453.316, 453.321, 453.322, 453.333, 453.334, 453.337, 453.338 or 453.401, any previous convictions of the offender for a felony relating to controlled substances must be alleged in the indictment or information charging the primary offense, but the conviction may not be alluded to on the trial of the primary offense nor may any evidence of the previous offense be produced in the presence of the jury except as otherwise prescribed by law. If the offender pleads guilty or guilty but mentally ill to, or is convicted of, the primary offense but denies any previous conviction charged, the court shall determine the issue after hearing all relevant evidence. A certified copy of a conviction of a felony is prima facie evidence of the conviction.
NRS 453.348