Missouri Code of State Regulations
Title 20 - DEPARTMENT OF COMMERCE AND INSURANCE
Division 2220 - State Board of Pharmacy
Chapter 3 - Negative Generic Drug Formulary
Section 20 CSR 2220-3.011 - Generic Drug Substitution

(1) Except as otherwise provided by Chapter 338, RSMo, a pharmacist who receives a prescription for a brand name drug or biological product may select a less expensive generically equivalent or inter-changeable biological product unless the patient requests a brand named drug or biological product or the prescribing practitioner indicates that substitution is prohibited or displays "brand medically necessary", "dispense as written", "do not substitute", "DAW", or words of similar import on the prescription.

(2) All pharmacists and dispensing physicians should be warned that any drug product not holding an approved New Drug Application or Abbreviated New Drug Application may not be used as a substitute in the state of Missouri without the dispenser assuming some personal liability.

(3) A pharmacist shall not substitute drug products that are rated as therapeutically in equivalent to other pharmaceutically equivalent products as listed in the latest edition or cumulative supplement of The Approved Drug Products with Therapeutic Equivalence Evaluations published by the United States Government, Department of Health and Human Services.