Sunday, January 1, 2012

Cymbalta (duloxetine)

Cymbalta (duloxetine) is a new serotonin norepinephrine re uptake inhibitor (SNRI) antidepressant medication developed by Lilly Pharmaceuticals.  After the Tricyclic medications which were the first truly effective antidepressant medications which came out in the early 50's, prozac became available as the first of the Serotonin Specific Reuptake Inhibitors (SSRI's)..  Subsequently antidepressants like Effexor were developped which worked on both the serotonin neurotransmitter pathways and the norepinephrine neurotransmitter pathways.  Cymbalta is not there fore the first SNRI.
What it is however is the first of this class of medications which has FDA approval for pain disorders.  Prior to this amitryptalline, a tricyclic antidepressant was the treatment of choice for fibromyalgia for instance.  However patients commonly complained that they only had limitted benefit and the tricyclics have alot of hard to tolerate side effects.  The side effects in general assocaited with all the new antidepressants are mostly annoying and not particularly dangerous. The tricyclics however could cause heart failure.
Cymbalta in contrast is a major breakthrough and relatively safe with much fewer side effects than those early antidepressants. Already it has given many patients improvement in pain which they did not have from any non narcotic agents. .
Naturally when a new medication is developed the pharmaceutical company would like everyone to switch to this medication. Medications are like cars in this regard.  Commonly family physicians and psychiatrists are given 'free samples' to help start patients on the latest medication.  This is a marketting strategy but it's also a very valuable clinical tool. Commonly in psychiatry a patient may have to try more than one medication before that which is most effective is found. Each time they fill a prescription they are charged the full amount even if they can't tolerate the medication or it's ineffective and they stop it aftera a few weeks. Free samples allow a patient to try a medication without cost to them and if it works without negative side effects then they can fill the prescription.
I have some patients who are still taking the original tricyclic medication prescribed to them 30 or more years ago. It worked then and it works now. Several other patients responded to later SSRI's called Paxil and Zoloft.  They benefited from these medications when they had their first bout of depression, recovered and stopped the medication only to have the depression occur 5 or 10 years later. I tend to try the medication that worked for them before in the hope that they will benefit from this once again. It's not disimiliar to antibiotics in that way.
Roughty 75% of patients with depression or generalized anxiety will respond to whichever antidepressant you choose first time.  Of the 25 % non responders, roughly 75% of them will respond to the second line choice.
When I worked in the states patients without plans would ask for the cheapest medications and I'd be able to know the oldest cheapest antidepressant would do the trick but the side effect profiles were a concern. Not unlike cars, the shocks on the old ones aren't what they are today.  Prozac was a break through in medication as compared to the tricyclics and MAOI inhibitors because it was hard to kill yourself with it.
The newer antidepressants collectively have a safer profile and overall improved side effect profile.  The antidepressants compared to most medications are very safe.
Cymbalta is effective for generalized anxiety disorder and depression.  So normally a specialist, especially a consulting specialist will see the 'non responders'.  There are patients in my practice who have simply not got better with any antidepressant medications and have been sent to me. This is where cymbalta is the 'first line choice of medication. I am truly happy to say that I have already seen Cymbalta work with non responders.
Further, people who had less than complete results with trials of several of the other classes of antidepressant medications have had excellent response to cymbalta.
Also benefitting are those people who have chronic depressions or anxiety disorders and whose medications seems to wear off after a year of two requiring higher dosage with increasing dose related side effects. These people tend to respond immedidately to the lowest dosage of an untried antidepressant medication, like Cymbalta.
What is offensive in psychiatry and why good universities demand that psychiatrists working for drug companies declare their bias is when these 'trend setters' make unreasonable claims for a new medication.  These colleagues get called 'drug company whores'as a result.  For instance they might say some new medications has a 95 % success rate with depression or suggest that patients already responding well to an earlier antidepressant medication should suddenly switch to the newest and more expensive medication.  For this sell out they get a trip to Hawaii or help getting up the academic ladder.
The fact is Cymbalta has something the other medications don't have and for that reason is my first line choice when I'm treating a combination of either a generalized anxiety disorder or depression with a pain disorder. My patients especially the older ones with traumatic athritis and those with fibromyalgia and even a patient with migraines have reported significant improvement in their pain as a result of starting cymbalta.
This happened when I gave wellbutrin, also marketted as zyban, to smokers with depression, a number of them found it easier to quit somking. Hence if I have a patient who wants to quit smoking and has depression I would consider well butrin as a first line treatment.  Wellbutrin is also called buproprion and has been used successfully extensively in addiction psychiatry.
Cymbalta now is the new drug of choice for that mixed state where pain and depression or anxiety prevail.  I love scientific advances in psychopharmacology and this truly is.  My fibromyalgia patients are especially pleased with it's benefit.
The side effect profile is roughly the same as effexor with some nausea and possibly tendency to make one sleepy.  The key is starting the medication at 30 mg and slowly titrating it upwards to the best dose for the patient, which so far in my practice has been in the 60 to 90 mg range though it's likely to be beneficial at double this dosage or it may turn out there's a window between 60 and 120. It's too early to tell but responses are being noted in the early weeks at as low as 30 mg which was what we saw when we started using prozac and 10 mg to 20 mg was sufficient.  Later we learned that obsessive compulsive patients often needed 60 to 80 mg and it's possible there will be a subcategory of patients who need higher dosages of Cymbalta. For now I'm just really thankful to Lilly for providing a product that is such a breakthrough.
Pharmaceutical companies spend millions and millions on research and development something the 'health food industry' is not in the habit of doing.  Consider the making of a new Hollywood movie with all the jobs and all the new ideas and compare that to late night 're runs'. That can be said for alot of 'alternative medicine'. Yes I know their are exceptions but I think people forget that these are 'big business' too and don't appreciate the contributions that are provided by the pharmaceutical industry.
Almost all my patients have tried 'everything' when they get to me.  I am thankful for all the help I can get. Cymbalta is just that kind of help. Lilly is a great pharmaceutical company that has done amazing research and provided great breakthrough in medications. Thank you, Lilly.

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