(1) A licensed prescriber may authorize a pharmacist to substitute a drug with another drug in the same therapeutic class that would, in the opinion of the pharmacist, have a substantially equivalent therapeutic effect even though the substitute drug is not a therapeutic equivalent drug, provided the following conditions are met:
(a) The prescriber has clearly indicated that drug product substitution is permissible by indicating "therapeutic substitution allowed" or by making a similar designation;
(b) The drug product substitution is intended to ensure formulary compliance with the patient’s health insurance plan or, in the case of a patient without insurance, to lower the cost to the patient while maintaining safety;
(c) The patient opts in to the drug product substitution, and the pharmacist clearly informs the patient of the differences in the drug products and specifies that the patient may refuse the substitution; and
(d) If a drug product substitution is made:
(i) The prescriber’s directions are modified to allow for an equivalent amount of drug to be dispensed as prescribed; and
(ii) The pharmacist shall notify the patient’s original prescriber of the drug product substitution within five (5) business days of dispensing the prescription.
(2) Nothing in this section shall apply to biological products, as set forth in section 54-1769, Idaho Code, or to narrow therapeutic index drugs.
(3) For purposes of this section:
(a) "Drug product substitution" means dispensing a drug product other than the drug product originally prescribed.
(b) "Narrow therapeutic index drug" means a drug where a small difference in dose or blood concentration may lead to serious therapeutic failures or adverse drug reactions.
(c) "Therapeutic class" means a group of similar drug products that have the same or similar mechanisms of action and are used to treat a specific condition.
(d) "Therapeutic equivalent drug" means a product assigned an "A" code by the federal food and drug administration (FDA) in the "Approved Products with Therapeutic Equivalence Evaluations" (orange book) and animal drug products published in the FDA’s "Approved Animal Drug Products" (green book).