National Consumers League

Consumers wary of therapeutic substitution

Therapeutic substitution, known also as drug switching and therapeutic interchange, is the practice of replacing a patient’s prescription drugs with chemically different drugs that are expected to have the same clinical effect. Many times patients switch to a different drug with no problems. However, for certain medications and conditions, therapeutic substitution could cause problems.

Consumers with a few specific conditions may be more likely than others to encounter a switch. Here are some of the conditions in which therapeutic substitutions may be more common, as well as the concerns about substitution expressed by some patient groups. As always, it is important to talk to your doctor about any potential therapeutic substitution.

In the lists of medicines, the Brand Name comes first, (and generic version is in parentheses).

Antidepressants stimulate chemical changes that increase the levels of neurotransmitters in the brain responsible for a person’s mood.

Some examples of antidepressants:
Prozac (fluoxetine), Zoloft (sertraline), Paxil (paroxetine), Luvox (fluvoxamine), Celexa (citalopram), and Lexapro (escitalopram). Antidepressants are associated with drug groups known as MAOIs, tricyclics, and SSRIs and are commonly prescribed by psychiatrists and other physicians to treat depression, bipolar disorder, and other mental illness.

Substitution concerns:
The American Psychiatric Association, Mental Health America, National Alliance on Mental Illness, and the National Council for Community Behavioral Healthcare oppose therapeutic substitution based on the substantial risk of serious adverse outcomes in people with mental illness. These groups support policies that provide patient access to the medications their doctors think they need, and they encourage shared patient-physician decisions based on the unique needs of individuals.

Cardiovascular Medications
There are several classes of drugs used to protect your heart, monitor your cholesterol level and blood pressure, and prevent other damage.

  • ACE inhibitors are used for controlling blood pressure, treating heart failure, preventing stroke, and preventing kidney damage in people with hypertension or diabetes. They also improve survival rates in patients who have had a heart attack.
  • Examples of ACE Inhibitors include: Capoten (captopril), Vasotec (enalapril), Prinivil (lisinopril), Accupril (quinapril) and Univasc (moesxipril)
  • Statins are used to lower cholesterol levels in people at risk of developing heart disease.
  • Examples of statins include: Lipitor, Zocor (simvastatin), Crestor, Pravachol (pravastatin), Mevacor (lovastin).

Substitution concerns:
The American Heart Association and the American College of Cardiology oppose therapeutic substitution and believe that only the prescribing doctor is equipped to determine the best drug or combination of drugs. These organizations believe that therapeutic substitution may result in the patient receiving a drug that doesn’t work well enough, produces life-threatening toxicity, or interacts dangerously with other drugs the patient is taking.

Epileptic medications
The drugs taken by patients with epilepsy are called antiepileptic drugs (AEDs) and are designed to change the electrical signaling in the brain to stop or prevent seizures. 

Examples of AEDs include:

Dilantin (phenytoin), Luminal (phenobarbital), Tegretol (carbamazepine), Neurontin (gabapentin), Lamictal (lamotrigine), Gabitril, Keppra, and Zonegran (zonisamide).

Substitution concerns:
The Epilepsy Foundation is concerned that there are enough differences among AEDs that any kind of medication substitution, (including switching from brand-name to generic), could be dangerous, and it could result in less control over seizures. The Epilepsy Foundation says that changing from one drug formulation to another can usually be done successfully if the patient’s blood levels, seizures, and toxicity are carefully monitored, but it says any medication change must require the permission of the treating doctor and the patient.

Proton-pump Inhibitors
Patients with dyspepsia, peptic ulcer disease, or acid-reflux may be prescribed a proton-pump inhibitor (PPI), drugs that result in long-lasting reduction of gastric acid production.

Examples of PPIs include:

Prilosec (omeprazole), Prevacid (lansoprazole), Nexium.

Substitution concerns:

As with any substitution, it is important to talk to your doctor, and be aware of the benefits and risks of substitution.