(1) Except as limited by subsection (2) and unless instructed otherwise by the purchaser:
(a) a pharmacist who receives a prescription for a specific drug product by brand or proprietary name may select a less expensive drug product with the same generic name, strength, quantity, dose, and dosage form as the prescribed drug that is, in the pharmacist's professional opinion, therapeutically equivalent, bioequivalent, and bioavailable; and
(b) a pharmacist who receives a prescription for a specific biological product may select a less expensive interchangeable biological product.
(2) If, in the professional opinion of the prescriber, it is medically necessary that an equivalent drug product or interchangeable biological product not be selected, the prescriber may so indicate by certifying that the specific brand-name drug product prescribed or the specific brand-name biological product prescribed is medically necessary for that particular patient. In the case of a prescription transmitted orally, the prescriber must expressly indicate to the pharmacist that the specific brand-name drug product prescribed or the specific biological product prescribed is medically necessary.
(3) A pharmacist who selects a drug product, as provided in this section, shall notify the person presenting the prescription that the person may refuse the product selection.