ROCHESTER, Minn., July 18 /PRNewswire-FirstCall/ -- Mayo Clinic is offering a new genetic test to help physicians identify patients who are likely to have side effects from drugs commonly used to treat depression.
Mayo has obtained a nonexclusive license from Pathway Diagnostics, Inc. to test for a key genetic marker that identifies people who respond differently to antidepressants, including selective serotonin reuptake inhibitors (SSRI). SSRIs act specifically by binding to the serotonin transporter, and increase the concentration of the neurotransmitter serotonin in the synapse. These medications include fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa) and escitalopram (Lexapro).
The test will be offered to patients nationwide through Mayo Medical Laboratories (MML), the reference laboratory for Mayo Clinic.
A 2003 study in the Journal of Clinical Psychiatry estimated the annual economic impact of depression in the Unites States at $83.1 billion, and one of six Americans will have at least one depression episode in their lifetime. Treatment choices are complicated because it often takes several weeks to determine whether a drug is having a therapeutic effect.
The 5HTTLPR biomarker has potential to improve management of patients with major depression and others who benefit from SSRI treatment. It provides unique information relating to drug response: side effect and compliance.
The Long/Long (L/L) genotype confers compliance to a SSRI whereas the Short/Short (S/S) genotype indicates an increased compliance with a noradrenergic and specific serotonergic antidepressant (e.g., mirtazapine).
“The serotonin transporter genotype assists the physician in making a better choice of antidepressant medications for their specific patient,” said Dennis O’Kane, Ph.D., director of the Nucleotide Polymorphism Laboratory at Mayo Clinic that validated the serotonin transporter testing. “Patients can be prescribed antidepressants that have a greater probability of being effective in their individual case, based upon their serotonin transporter genotype used in conjunction with CYP450 genotyping testing. Depending upon genotypes, some patients should respond well to SSRIs, some may respond to SSRIs but more slowly, and some patients may respond more effectively to non- SSRI antidepressants.”
“Depressive disorders affect over 18 million American adults,” says Wally Narajowski, president and CEO of Pathway Diagnostics. “Prescribing the right antidepressant therapy at the right dose is a medication management challenge. We are pleased to work with Mayo Medical Laboratories to provide tools that will help address this challenge.”
Published studies in the medical literature have estimated that 30 percent of patients treated with the existing antidepressant medications do not improve. In addition, 90 percent experience side effects and 30 to 40 percent do not respond to the first drug regimen. “Prescribing a correct antidepressant for the specific patient may increase the likelihood of patient compliance and decrease the loss of patients to follow-up,” says Dr. O’Kane.
The 5HTTLPR test is among the growing list of pharmacogenomic tests Mayo offers to help physicians personalize treatment options. Pharmacogenomics individualizes drug selection and dosing based on a person’s genomic makeup; pharmacogenomic testing can help determine which patients should receive which doses of which medications to avoid adverse drug reactions.
Mayo offers these proven diagnostic technologies to more than 5,000 health care institutions around the world through MML. Working with the Department of Neurology at Mayo Clinic, the Department of Laboratory Medicine and Pathology refined and validated this 5HTTLPR genotype test for use by its physicians, and will offer it to other health care organizations through MML. Mayo will offer education to providers on the benefits of this important screening test to ensure that patients everywhere have access to it.
The Department of Laboratory Medicine and Pathology at Mayo Clinic maintains an active diagnostic test development program. These activities also incorporate discoveries, such as the 5HTTLPR biomarker, made elsewhere. Revenue from MML testing and technology licensing is used to support medical education and research at Mayo Clinic.
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Mayo Clinic
CONTACT: Lee Aase of Mayo Clinic, +1-507-284-5005 (days), or+1-507-284-2511 (evenings), or newsbureau@mayo.edu
