Therapeutic Substitution Widens Existing Health Disparities in the Underserved
By: Tish Bridges Hill, M.D., M.B.A.
Studies have clearly and definitively delineated the existence of racial and ethnic health disparities in insured and uninsured minority populations. Access to a usual source of care, cultural norms, language barriers and numerous other etiologic agents lead to these disparities. Current legislative discussions focus on access to care, but fail to address existing insurance practices that perpetuate disparities in minority groups. In particular, the practice of therapeutic switching has potentially deleterious effects on patient outcomes.
Therapeutic substitution, also known as drug switching, is the practice of replacing a patient's prescription drug with a chemically different drug that is expected to have the same clinical effect. This is fundamentally distinct from generic substitution where a less expensive, biochemically identical drug is substituted for the prescribed medication. Therapeutic substitution is particularly common with antidepressants, cardiovascular and antiepileptic medications. Unbelievably, such therapeutic substitutions occur regularly, often without prescribing physician and patient knowledge.
Therapeutic substitution is problematic in all patient groups, but can be particularly detrimental in special populations - racial and ethnic minorities, the poor, the elderly, children, and individuals with multiple co-morbidities. It is well known that genetic, cultural and environmental factors influence variations in drug metabolism and response. As a result, drug switching in racial and ethnic minorities increases the risk of sub optimal drug effect and adverse reactions.
As a rule, drug therapy for minority populations should be individualized to achieve the most effective response. A core component of culturally competent health care is the knowledge of drug response in minority populations. Different medications in the same therapeutic drug class are often processed by different metabolic pathways. In addition, the biochemical basis of the disease may differ among racial groups, and some medications will be more effective than others in certain racial groups.
Healthcare institutions and insurers should rigorously avoid the practice of therapeutic substitution. Drug treatment decisions should remain in the realm of competent practicing physicians whose goal is to optimize patient health. Only the prescribing doctor is equipped to ascertain the best drug or combination of drugs for a given patient. At the very least, patients and physicians should be consulted and given the right to refuse this change in treatment driven by financial incentives. Routine use of cost containment practices subjugate the physician's decision making capacity and ultimately places corporate profit margins ahead of patient health.
Dr. Tish Bridges Hill is a practicing General Surgeon in Los Angles and the current President of the Association of Black Women Physicians.