Description: SNRIs (serotonin–norepinephrine reuptake inhibitors) are used to treat major depressive and other mood disorders, anxiety disorders, and nerve pain. They may also be used to treat obsessive-compulsive disorder, attention deficit hyperactivity disorder (ADHD) and fibromyalgia syndrome. The SNRIs are second generation anti-depressants. The older tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) have less tolerability and more side effects than the newer, second generation anti-depressants.
SNRIs helps elevate levels of serotonin and norepinephrine, which are neurotransmitters (chemicals which help brain cells communicate with one another) that play an important role in mood. SNRIs, like the related SSRIs (selective serotonin reuptake inhibitors) increase serotonin levels and share some of the same side effects.
Common Side Effects of SNRIs
The most common side effects from SNRI medications include loss of appetite, inability to sleep and weight loss. Other side effects include: drowsiness, fatigue, dizziness, increase in suicidal thoughts, sexual dysfunction, nausea and vomiting and urinary retention. Raised epinephrine levels can also cause anxiety, mildly elevated pulse and elevated blood pressure. People at risk for heart disease should have their blood pressure monitored during treatment.
Understand Your Risks with the Rxight® Genetic Test
The Rxight® pharmacogenetic testing program allows prescribers to know ahead of time how predisposed an individual is to side effects from SNRIs and over 200 other prescription and over-the-counter medications across dozens of clinically significant medication classes. All that is required is a simple cheek swab of your DNA by a participating pharmacist.
How Does Pharmacogenetic Testing Work?
Physicians have long been using the “trial and error” approach to choosing the specific medication and its dose since there was no other way to find out how a particular patient would respond to the drug, other than the label information, after FDA approval. Before a drug is approved, it is tested, but the numbers of patients in clinical trials do not reflect the wide variation among people.
Rxight® is grounded in the science ofpharmacogenetics, a relatively new field which has emerged from the sequencing of the human genome.
Sequence variation in a gene entails that the enzyme made from the genetic instructions vary from person to person. An altered drug metabolism enzyme may mean that you may not be able to take certain drugs, or that your dose should be increased or decreased from the standard dose for optimal safety and treatment efficacy.
Contributors to this Article:
Michael Sapko, MD, PhD; Deborah Kallick, PhD, Medicinal Chemistry