Nearly ¾ of Americans say they’d be concerned if their medication was switched without their consent or the consent of their doctor. However, a common practice called therapeutic substitution allows pharmacists to switch a patient’s drugs as long as they’re in the same pharmaceutical class.
What is Therapeutic Substitution?
Therapeutic substitution is designed to reduce costs to drug plans by limiting coverage to the cheapest product. This can affect patients starting a new medication or those who are filling a prescription they’ve had for some time.
The policy assumes that medications in the same therapeutic class are interchangeable because their mechanisms of action don’t differ significantly, despite slight differences chemically.
Pharmacists can fill the cheaper option without consulting the physician or patient.
This practice is regulated and varies for each state according to their individual Pharmacy Practice Act. There are essentially four different options:
- The positive formulary approach – a list of generic drug products are provided that can be substituted for one another
- The negative formulary approach – a list of drug products is provided for which substitution is NOT allowed.
- Combined positive and negative formularies – both of the above lists are provided
- A “nonformulary” approach – pharmacists must ensure that substitutions are made within the requirements of state law (often as defined by Orange Book A-rated products)
In addition, health insurers often offer incentives to pharmacies to participate in this practice. This often leads to individual pharmacists having to meet certain quotas or goals on how much money is saved or how often a certain drug was substituted.
How does this affect patients?
The American Academy of Family Physicians strongly opposes states allowing therapeutic substitution. Therapeutic differs from generic substitutions because generic substitution can only be done legally if the product contains the same chemical components as the brand name product. They must be bioequivalent.
The risks of therapeutic substitution can be high as the replacement drug may not work as well, or it might work differently. It could have different side effects, and/or interact differently with other medication or foods.
Potential benefits include lower cost, and possible convenience (you may have to take it less often, etc).
What should patients do?
While pharmacies are regulated by the insurance companies in terms of having to fill a cheaper prescription option, patients do still have control over what medications they use. It’s important to always pay attention to the prescription your doctor provides and what prescription is actually filled.
If you find a prescription has been substituted:
- Ask you pharmacist why. Is the other drug not covered by your insurance? Or is this one just cheaper?
- Contact your doctor to see if they feel the switch is okay. For many drugs and patients, the change may have no negative effects.
- If you talk to your doctor and they do not advise the switch, have them re-write the prescription or contact the pharmacy and specify that no substitutions can be made for medical reasons
If you do proceed with switching your medication, be sure you review if there is any change in potential side effects or interactions, so you know what to look out for.
As a physician do you think substitutions are acceptable or should they be avoided? Have you ever had an issue with a patient outcome because of a switched medication? We’ll be discussing this and more clinical topics inside Sermo, if you’re an M.D. or D.O. please join us.
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