May 27, 2015
Generic vs. Brand Name Drugs: What are the Differences?
Reuel S. Amdur
More by this author...Generic medicines are not equivalent to the matching brand-name formulations. That was one message that Dr. Pierre Blier gave at a lecture presented at Ottawa's Royal Ottawa Hospital on May 21.
Blier is a Professor of Psychiatry and Cellular and Molecular Medicine at the University of Ottawa, Canadian Research Chair in Psychopharmacology, and Director of the Mood Disorders Research Unit at the Royal Ottawa Hospital.
So what is the problem?
There can be slight molecular differences in the ingredients, and the allowed variance in active ingredient for a generic equivalent is between 80 and 125%, he said.
Let’s unpack that a bit.
First, on the molecular difference, Blier showed a comparison of molecules, where the brand-name drug had a few other-shaped molecules scattered about, while the generic sample was uniform.
On the issue of variance, a University of Saskatchewan report (“Generic vs. Brand Name Drugs: What are the Differences?”) states that the spread measures “the concentration of a drug over time as it is absorbed into the body and then slowly released from the body.”
Thus, “the actual variance is less than 5%, with studies finding an average variance of 3-4%.” And “different batches of the same brand name drug are allowed to have the same variance.”
Nevertheless, Blier held that switching from a brand-name drug to a generic equivalent can sometimes result in serious consequences, especially for some psychiatric patients.
In some cases, negative consequences are, he said, irreversible. A condition that was well-controlled deteriorates. We might wonder, however, if the slight molecular differences are the determining factor. And if the problem is one of switching from brand-name medication to generic, perhaps the answer would be to begin with and stick to the generic.
Blier referred InnoviCares.ca, a website which provides cards with which it is possible to obtain a brand-name drug at the generic price. This site does not cover all medications, and there is no guarantee that a drug will continue to be listed. As well, not all pharmacists cooperate with this program. He mentioned Quebec as a province in which many pharmacists will not.
He is part of an international committee to address how drugs are labeled.
The problem is that a drug may be used for more than one condition. Taking an extreme example, he noted that a drug for tuberculosis, when given to tubercular patients, was also found to treat the depression experienced by some, and it is now used to treat depression as well.
Currently, he argued, names especially for psychotropic drugs are “very confusing.”
Labels are based on their initial licensing for clinical action. As a result, faulty conclusions may be drawn. Are “anti-depression” medications overused? The question is not easily answered, in spite of some glib efforts. A drug so labeled can also be used to treat anxiety, promote sleep, counteract low energy, treat migraine, manage pain, and treat fibromyalgia.
In some cases, you can treat different conditions by changing the dosage. He gave the example of ASA (brand name Aspirin). At 1000 milligrams it is an analgesic, while at 81 it is an anticoagulant. And a single dose of some drug may be used with more than one condition in mind for the particular patient.
The committee on which he sits is looking to categorize drugs differently. What is now called an anti-depressant should more properly be known as a drug which treats depression. It also can treat other conditions.
Now the committee looks to characterize drugs on four dimensions—1) target and mode of action; 2) approved indications; 3) efficacy and main side effects; and 4) microbiology.
The characterization is not the full answer to use, for example as to side effects. In that regard, it might be important to refer to treatment guidelines for the particular medication. Yet, it is hoped that this new approach will be an improvement over characterizing a multi-purpose medication as an anti-depressive or anti-psychotic. It can, Blier explained, be disturbing to a person who is not psychotic to be prescribed a medication termed an anti-psychotic.