What rating indicates that a drug product can be therapeutically substituted?

The rating that indicates a drug product can be therapeutically substituted is an A rating. This designation means that the drug is considered bioequivalent to its reference product, indicating that it meets the necessary pharmacokinetic and pharmacodynamic criteria for a therapeutic interchange. Essentially, an A-rated drug can be expected to have the same efficacy and safety profile as the original branded medication, making it appropriate for substitution in the treatment plan of a patient.

In practice, A-rated drugs are allowed to be used interchangeably in therapeutic settings, often leading to cost savings and providing patients with access to equally effective alternatives. This rating comes from the FDA's classification of drug products, which assesses their equivalence based on established standards.