Tuesday, March 11, 2008

Liebowitz Sets the Record Straight on Pristiq Views

I recently posted this critique of Wyeth's newly approved antidepressant Pristiq, and in that article I quoted Dr. Michael Liebowitz, who was the lead investigator on some of the Pristiq clinical trials. Dr. Liebowitz contacted me because he felt I had mischaracterized his opinions. I invited him to send me a clarification, which I offered to print in full. In reviewing this issue, I plead guilty to having taken some of his comments out of context, and I apologize to Dr. Liebowitz for having done so. These are his views on Pristiq, in his own words:

"Your blog posting suggesting I was unenthusiastic about Pristiq mischaracterized my views. It is very useful for clinicians to have another serotonin-norepinephrine reuptake inhibitor (SNRI) available to treat depression. This class of antidepressants is very useful for treating an often disabling and sometimes life threatening condition, and the more tools we as clinicians have available, the better we can serve our patients. In addition, Pristiq's very tolerable starting dose of 50 mg per day may also turn out to be its usual therapeutic dose, avoiding the need for dose escalation. If so, this would differentiate it from Effexor XR and Cymbalta, the two previously marketed SNRI's.

With regard to my remark that if Pristiq was useful, it would make money for Wyeth, this was in response to your question about whether the company was marketing it for altruistic or commercial reasons. The intent of my comment was twofold. First, I believe that it was not an either-or proposition. Rather, if the drug turned out to be highly useful, it would also be highly profitable, so a company can be motivated both by wanting to advance science and health care and make a profit. Secondly, how widely a given drug will be used is not always something one can usually predict until a drug is marketed and clinicians have a chance to test it out in daily clinical situations. For example, who would have predicted that Celexa or Lexapro, marketed for depression after numerous other SSRI's, would turn out to be very useful, popular and widely used drugs.

Sincerely yours,

Michael Liebowitz M.D.
Professor of Clinical Psychiatry
Columbia University"

1 comment:

Anonymous said...

Current Depression Medications: Do The Benefits Outweigh the Harm?

Presently, for the treatment of depression and other what some claim are mental disorders, some of which are questionable, selective serotonin reuptake inhibitors are the drugs of choice by most prescribers. Such meds, meds that affect the mind, are called psychotropic medications. SSRIs also include a few meds in this class with the addition of a norepinephrine uptake inhibitor added to the SSRI, and these are referred to SNRI medications. Examples of SNRIs are Cymbalta and Effexor. Some consider these classes of meds a next generation after benzodiazepines, as there are similarities regarding their intake by others, yet the mechanisms of action are clearly different, but not their continued use and popularity by others.

Some Definitions:

Serotonin is a neurotransmitter thought to be associated with mood. The hypothesis was first suggested in the mid 1960s that this neurotransmitter may play a role in moods and emotions in humans. Yet to this day, the serotonin correlation with such behavioral and mental conditions is only theoretical. In fact, the psychiatrist’s bible, which is the DSM, states that the definite etiology of depression remains a mystery and is unknown. So a chemical imbalance in the brain is not proven to be the cause of mood disorders, it is only suspected with limited scientific evidence. In fact, diagnosing diseases such as depression is based on subjective assessment only, as interpreted by the prescriber, so one could question the accuracy of such diagnoses.

Norepinephrine is a stress hormone, which many believe help those who have such mood disorders as depression. Basically, with the theory that by adding this hormone, the SSRI will be more efficacious for a patient prescribed such a med.
And depression is only one of those mood disorders that may exist, yet possibly the most devastating one. An accurate diagnosis of these mood conditions lack complete accuracy as they can only be defined conceptually, so the diagnosis is dependent on subjective criteria, such as questionnaires. There is no objective diagnostic testing for depression. Yet the diagnosis of depression in patients has increased quite a bit over the decades. Also, few would argue that depression does not exist in other people. Yet, one may contemplate, actually how many other people are really depressed?
Several decades ago, less than 1 percent of the U.S. populations were thought to have depression. Today, it is believed that about 15 percent of the populations have depression at some time in their lives. Why this great increase in the growth of this condition remains unknown and is subject to speculation. What is known is that the psychiatry specialty is the one specialty most paid to by certain pharmaceutical companies for support of their psychotropic meds, as this industry clearly desires market growth of these products, as this objective is part of their nature. Regardless, SSRIs and SRNIs are the preferred treatment methods if depression or other mood disorders that may be suspected by a doctor. Yet these meds discussed clearly are not the only treatments, medicinally or otherwise, for depression treatment.

Over 30 million scripts of these types of meds are written annually, and the franchise is around 20 billion dollars a year, with some of the meds costing over 3 dollars per tablet. There are about ten different SSRI/SRNI meds available, many of which are now generic, yet essentially, they appear to be similar in regards to their efficacy and adverse events. The newest one, a SNRI called Pristiq, was approved in 2008, and is being promoted for treatment for menopause. The first one of these SSRI meds was Prozac, which was available in 1988, and the drug was greatly praised for its ability to transform the lives of those who consumed this medication in the years that followed. Some termed Prozac, ‘the happy pill’. In addition, as the years went by and more drugs in this class became available, Prozac was the one of preference for many doctors for children. A favorable book was published specifically regarding this medication soon after it became so popular with others.
Furthermore, these meds have received additional indications besides depression for some really questionable conditions, such as social phobia and premenstrual syndrome. With the latter, I find it hard to believe that a natural female experience can be considered a treatable disease. Social phobia is a personality trait, in my opinion, which has been called shyness or perhaps a term coined by Dr. Carl Jung, which is introversion, so this probably should not be labeled a treatable disease as well. There are other indications for certain behavioral manifestations as well with the different SSRIs or SRNIs. So the market continues to grow with these meds. Yet, it is believed that these meds are effective in only about half of those who take them, so they are not going to be beneficial for those suspected of having certain medical illnesses treated by such meds. The makers of such meds seemed to have created such conditions besides depression for additional utilization of these types of medications, and are active and have been active in forming symbiotic relationships with related disease specific groups, such as providing financial support for screenings for the indicated conditions of their meds- screening of children and adolescents in particular, I understand, and consider dangerous and inappropriate for several reasons.

Danger and concern primarily involves the adverse effects associated with these types of meds, which include suicidal thoughts and actions, violence, including acts of homicide, and aggression, among others, and the makers of such drugs are suspected to have known about these effects and did not share them with the public in a timely and critical manner. While most SSRIs and SNRIs are approved for use in adults only, prescribing these meds to children and adolescents has drawn the most attention and debate with others, such as those in the medical profession as well as citizen watchdog groups. The reasons for this attention are due to the potential off-label use of these meds in this population, yet what may be most shocking is the fact that some of the makers of these meds did not release clinical study information about the risks of suicide as well as the other adverse events related to such populations, including the decreased efficacy of SSRIs in general, which is believed to be less than 10 percent more effective than a placebo. Paxil caught the attention of the government regarding this issue of data suppression some time ago, this hiding such important information.

And there are very serious questions about the use of SSRIs in children and adolescents regarding the effects of these meds on them. For example, do the SSRIs correct or create brain states considered not within normal limits, which in effect could cause harm rather than benefit? Are adolescents really depressed, or just experiencing what was once considered normal teenage angst? Do SSRIs have an effect on the brain development and their identity of such young people? Do adolescents in particular become dangerous or bizarre due to SSRIs interfering with the myelination occurring in their still developing brains? No one seems to know the correct answer to such questions, yet the danger associated with the use of SSRIs does in fact exist. It is observed in some who take such meds, but not all who take these meds. Yet health care providers possibly should be much more aware of these possibilities.

Finally, if SSRIs are discontinued, immediately in particular instead of a gradual discontinuation, withdrawals are believed to be quite brutal, and may be a catalyst for suicide in itself, as not only are these meds habit forming, but discontinuing these meds, I understand, leaves the brain in a state of neurochemical instability, as the neurons are recalibrating upon discontinuation of the SSRI that altered the brain of the consumer of this type of med. This occurs to some degree with any psychotropic med, yet the withdrawals can reach a state of danger for the victim in some classes of meds such as SSRIs, it is believed.

SSRIs and SRNIs have been claimed by doctors and patients to be extremely beneficial for the patient’s well -being regarding the patient’s mental issues where these types of meds are used, yet the risk factors associated with this class of medications may outweigh any perceived benefit for the patient taking such a drug. Considering the lack of efficacy that has been demonstrated objectively, along with the deadly adverse events with these meds only recently brought to the attention of others, other treatment options should probably be considered, but that is up to the discretion of the prescriber.

“I use to care, but now I take a pill for that.” --- Author unknown

Dan Abshear