4.2 Generic Drug Substitution, Interchangeable Biologics & Biosimilars

4.2 Generic Drug Substitution, Interchangeable Biologics & Biosimilars

The Legal Framework for Generic Substitution

Generic drug substitution is a critical component of pharmacy practice in Georgia, designed to help reduce healthcare costs for patients and the broader healthcare system while maintaining high standards of clinical efficacy and patient safety. The Georgia Pharmacy Practice Act sets forth explicit guidelines dictating when a pharmacist must, may, or must not substitute a generic equivalent for a prescribed brand-name medication.

In Georgia, the law mandates a permissive substitution framework that leans heavily toward substitution. A pharmacist is authorized to dispense a generic equivalent drug for a brand-name drug if the generic product is therapeutically equivalent and has the same active chemical ingredients, same strength, same dosage form, and is administered via the same route of administration. Furthermore, the generic product must be priced lower to the patient than the brand-name product. The pharmacist is required to dispense the lowest retail priced drug in stock that is therapeutically equivalent to the prescribed brand-name drug, unless the prescriber explicitly restricts substitution.

The primary reference used to determine therapeutic equivalence is the FDA's "Approved Drug Products with Therapeutic Equivalence Evaluations," commonly known as the Orange Book. Drugs that are "A-rated" in the Orange Book are considered therapeutically equivalent and can be substituted. This includes ratings such as AB, AA, AN, AO, AP, and AT. Conversely, drugs that are "B-rated" are not considered therapeutically equivalent due to documented or potential bioequivalence problems, and substitution of B-rated products is strictly prohibited under Georgia law.

Prohibiting Substitution: "Brand Medically Necessary"

While the state encourages generic substitution, the ultimate authority over patient therapy remains with the prescriber. A prescriber can easily override the pharmacist's ability to substitute a generic drug, but they must follow specific statutory procedures to do so. In Georgia, merely checking a pre-printed box or signing on a specific "Dispense as Written" line is insufficient to prevent generic substitution on a written prescription.

For a written prescription, the prescriber must write the exact phrase "Brand Necessary" or "Brand Medically Necessary" in their own handwriting on the face of the prescription document. The law expressly prohibits the use of pre-printed check boxes, stamps, or pre-printed wording to fulfill this requirement. This strict handwriting requirement ensures that the prescriber has made a conscious, deliberate clinical decision that the specific patient requires the brand-name medication.

For electronic prescriptions, the constraints of handwriting obviously do not apply. In the realm of e-prescribing, the prescriber must make an affirmative, active selection within their electronic health record (EHR) system indicating that substitution is prohibited. This is typically transmitted as a specific "Dispense as Written" (DAW) code (e.g., DAW 1). If the electronic prescription does not contain this specific, deliberate indication, the pharmacist is fully authorized—and indeed expected—to substitute the therapeutically equivalent generic product.

For verbal prescriptions, the prescriber or their authorized agent must expressly state that the brand-name drug is medically necessary. The pharmacist must then document this instruction on the written record of the verbal prescription.

Patient Rights and Notification

Patients in Georgia have a fundamental right to know what medication they are receiving and to participate in the decision-making process regarding their healthcare costs. When a pharmacist receives a prescription that allows for generic substitution, they are required to dispense the lowest retail priced drug in stock. The pharmacist must record the specific manufacturer or distributor of the substituted generic drug on the prescription document or within the pharmacy's computerized records.

Furthermore, the pharmacist must ensure that the prescription label clearly indicates the identity of the generic drug dispensed. The label should typically include the generic name followed by the phrase "substituted for" and the brand name (e.g., "Atorvastatin substituted for Lipitor"). The pharmacist is also expected to inform the patient or the patient's representative about the substitution, providing them with the opportunity to refuse the generic and opt for the brand-name product, provided they are willing to pay the potentially higher cost or if their insurance permits it.

Interchangeable Biologics and Biosimilars

The landscape of pharmacy practice has rapidly evolved with the introduction of biological products and biosimilars. A biological product is a large, complex molecule manufactured in a living system, making exact generic copies impossible. Instead, the FDA approves "biosimilars," which are highly similar to and have no clinically meaningful differences from an existing FDA-approved reference product.

However, being a biosimilar is not enough to permit automatic substitution at the pharmacy level. The FDA must designate a biosimilar as an "interchangeable biological product." To achieve this designation, the manufacturer must prove that the product is expected to produce the same clinical result as the reference product in any given patient and that the risks of alternating or switching between the products are not greater than the risks of continuing the reference product.

The reference for biological products is the FDA's "Lists of Licensed Biological Products with Reference Product Exclusivity and Biosimilar or Interchangeability Evaluations," commonly known as the Purple Book.

In Georgia, a pharmacist may substitute an interchangeable biological product for a prescribed reference biologic under similar conditions as generic substitution. However, there are additional communication requirements. Within 48 hours of dispensing an interchangeable biological product, the pharmacist must communicate the specific product provided to the patient, including the name of the product and the manufacturer, to the prescribing practitioner. This communication can be accomplished through an interoperable electronic medical records system, an electronic prescribing technology, a pharmacy benefit management system, or a pharmacy record that the prescriber can access electronically. If these electronic means are unavailable, the pharmacist must notify the prescriber via facsimile, telephone, or other electronic transmission. This mandatory communication ensures the prescriber has an accurate record of exactly which biologic the patient is receiving, which is crucial for monitoring potential immunogenicity or adverse reactions.

Comparison of Substitution Requirements in Georgia