Okla. Stat. tit. 56, § 1010.12

Subject to the provisions of subsection B of Section 204 of Title 56 of the Oklahoma Statutes, effective September 1, 1998, children age eighteen (18) or younger may be prescribed non-sedating antihistamines under the state Medicaid plan without prior authorization by the Medicaid Drug Utilization Review Board. Adults age nineteen (19) or older shall continue to be subject to the prior authorization procedures of the Medicaid Drug Utilization Review Board for non-sedating antihistamines.