Serotonin and norepinephrine reuptake inhibitors (SNRIs)
Serotonin and norepinephrine reuptake inhibitors (SNRIs) are a class of drugs that are effective in treating depression. SNRI is sometimes used for the treatment of other conditions, such as anxiety disorder and long-term (chronic) pain, especially nerve pain. If you have chronic pain other than depression then SNRI can be helpful.
How SNRI Works
SNRI reduces depression by affecting the chemical messenger (neurotransmitters) used to communicate between the brain cells. Like most antidepressants, SNRIs eventually affect brain chemistry and communication in brain nerve cell circuits, which are known to regulate the mood, which helps in eliminating depression.
SNRIs block the reabsorption (reuptake) of the neurotransmitters serotonin (ser-o-TOE-nin) and norepinephrine (nor-ep-ih-NEF-rin) in the brain.
SNRI approves treatment for depression
The Food and Drug Administration (FDA) has approved these SNRIs for the treatment of depression:
- Desvenlafaxine (Pristiq, Khedezla)
- Duloxetine (Cymbalta) ― also approved to treat anxiety and certain types of chronic pain
- Levomilnacipran (Fetzima)
- Venlafaxine (Effexor XR) ― also approved to treat anxiety and panic disorder
Side Effects and Cautions
All SNRIs work in a similar way and usually have similar side effects, although some people may not experience any side effects. Side effects are usually mild and leave after the first few weeks of treatment. Nausea can be reduced by taking your medicine with food. If you can not afford a SNRI, then you may be able to tolerate a different one, because each SNRI is different in chemical makeup.
The most common side effects of SNRI include:
- Nausea
- Dry mouth
- Dizziness
- Headache
- Excessive sweating
Other possible side effects may include:
- Tiredness
- Constipation
- Insomnia
- Changes in sexual function, such as reduced sexual desire, difficulty reaching orgasm or the inability to maintain an erection (erectile dysfunction)
- Loss of appetite
Generally, the benefits of antidepressant are overtaken by potential side effects. Which antidepressant is best for you, depending on many issues, such as your symptoms and any other health conditions you may have.
Ask your doctor and pharmacist about the most common side effects of your specific SNRI and read the doctor’s medication guide that comes with prescription.
Safety Issues
SNRIs are safe for most people. However, in some circumstances they can cause problems. for example:
Venlafaxine, desvenlafaxine and levomilnacipran. These SNRIs can increase your blood pressure.
Duloxetine. This can worsen SNRI lever problems.
Other issues to discuss with your doctor before taking SNRI include:
Drug interactions. While taking an antidepressant, tell your doctor about any other prescriptions or over-the-counter medicines, herbs or other supplements that you are taking. Some antidepressants may cause dangerous reactions when combined with some medicines or herbal products. SNRI can increase the risk of bleeding, especially when you are taking other medicines that increase the risk of bleeding, such as aspirin or warfarin (Coumadin, Jantoven).
Serotonin syndrome. Rarely, serotonin syndrome can occur when you take antidepressants that can increase the level of serotonin in your body. This happens most often when two medicines that increase serotonin are combined, such as other antidepressants, some pain or headache medicines, or St. John Plant. Signs and symptoms of serotonin syndrome include anxiety, movement, sweating, confusion, shiver, discomfort, lack of coordination and rapid heart rate. If you have any of these symptoms, seek immediate medical help.
Antidepressants and pregnancy. Talk to your doctor about the risks and benefits of specific antidepressants. Some antidepressants can harm your child if you take them during pregnancy or during breastfeeding. If you are taking an antidepressant and are considering becoming pregnant, talk to your doctor about the potential risks. Do not stop taking your medication without contacting your doctor, because stopping can cause you a risk.
Suicide Risk and Antidepressant
Most antidepressants are usually safe, but the FDA requires that all antidepressants black box warning, the most difficult warning for prescriptions. In some cases, considering the antidepressants in children, adolescents and young adults under the age of 25 years, the idea or behavior of suicide can increase, especially after a few weeks of beginning or when the dose changes.
Anyone taking antidepressant should be seen closely for deteriorating depression or abnormal behavior. If you or someone you know has suicidal thoughts while taking antidepressant, contact your doctor immediately or get emergency help.
Keep in mind that improvements in antidepressant mood are more likely to reduce the risk of suicide in the long run.
Preventing Treatment with SNRIs
SNRI is not considered addictive. However, preventing sudden antidepressant treatment or withdrawing many doses may result in withdrawal symptoms. It is sometimes called dissection syndrome. Symptoms like withdrawal with venlafaxine or desvenlafaxine are more common. Work with your doctor to reduce your dose slowly and safely.
Symptoms may include withdrawal:
- Dizziness
- Headache
- Flu-like symptoms, such as tiredness, chills and muscle aches
- Irritability or agitation
- Nausea
- Diarrhea
Finding the Right Antidepressant
People can react differently on the same antidepressant. For example, a particular drug may work better – or not for you compared to another person. Or you may have more or less side effects than taking a specific antidepressant compared to someone else.
The underlying symptoms play a role in how Antidepressants influence you. In some cases, where available, the results of a special blood test can give clues about how your body can respond to a particular antidepressant. However, other than genetics, the variables can affect your reaction to the drug.
When choosing an antidepressant, your doctor has worked for you on your symptoms, any health problems, other medicines you take and for you in the past.
Typically, an antidepressant may take several weeks or more to be fully effective and reduce side effects. Before you can find out right, you may need to try many antidepressants, but hang them there. With patience, you and your doctor can get a medication that works well for you.