(a) As used in this section:
(1) “Issued” means the date that the licensed physician physically wrote or electronically transmitted the prescription to the pharmacy; and
(2) “Valid prescription” means a prescription that is written or electronically sent by a licensed practitioner for the individual subject to a drug test pursuant to this chapter and filled in a licensed pharmacy.
(b) Notwithstanding this chapter to the contrary, the medical review officer shall only consider prescriptions issued within six (6) months prior to a positive confirmed drug result for purposes of determining a valid prescription and immunity from actions authorized by this chapter following a positive confirmed drug result.