Understanding Antidepressants, Part 2: What Are SNRIs, and How Do They Work?
By Tannia Salazar, APRN | Rooted in Serenity Behavioral Health
In Part 1, we broke down SSRIs—how they support mood by preserving serotonin. If you’re seeking something that targets both mood and energy, or if pain is a factor, the next class worth exploring is SNRIs.
This post explains what SNRIs are, how they differ from SSRIs, their unique uses, and what side effects to expect.
What Does SNRI Stand For?
SNRI = Serotonin and Norepinephrine Reuptake Inhibitor.
Here's what that means:
Serotonin supports mood, sleep, appetite, and sense of calm
Norepinephrine aids focus, energy, and alertness
SNRIs help your brain hold onto both neurotransmitters longer—so they’re available to support your mood and energy balance
What SNRIs Are Commonly Prescribed?
You might hear these names:
Venlafaxine (Effexor)
Duloxetine (Cymbalta)
Desvenlafaxine (Pristiq)
Levomilnacipran (Fetzima)
These medications are helpful for depression and anxiety—but have also been found to aid with pain in conditions like neuropathy, fibromyalgia, or chronic musculoskeletal discomfort
How Do SNRIs Differ from SSRIs?
SSRIs target only serotonin.
SNRIs target both serotonin and norepinephrine.
Due to this, SNRIs can be more “activating” and may be more beneficial —better for those with low energy or persistent pain.
Common Side Effects: What You Might Notice
Side effects are often mild and temporary, especially in the first 1–2 weeks:
| Effect | How It Might Feel | When to Reach Out |
|---|---|---|
| Nausea | Slight stomach upset, especially on an empty stomach | Fades in a week or two; take with food |
| Dizziness | Lightheadedness when standing up quickly | Usually temporary with position changes |
| Insomnia | Trouble falling or staying asleep | Try adjusting dose timing |
| Sweating | Night sweats or increased warmth | Often transient |
| Higher blood pressure | Felt as tension or racing heart | Monitor if you have hypertension |
⚠️ Like all antidepressants, SNRIs may very rarely cause increased thoughts of suicide or serotonin syndrome—always reach out if anything changes.
Tapering & Discontinuation: Take It Slow
Stopping an SNRI suddenly—especially Venlafaxine and Pristiq—can cause what’s known as discontinuation syndrome. Symptoms might include flu-like feelings, dizziness, or "brain zaps." It’s imperative to taper slowly under clinical guidance without abrupt cessation.
Why SNRIs Might be the Right Choice
These are beneficial if you:
Need help with motivation and energy
Are managing chronic pain alongside with low mood
Don’t respond to SSRIs—or need a different mechanism of action
Are seeking improved focus or drive
The tone of medication isn’t about replacing recovery tools—it’s about strengthening your ability to engage in healing.
Final Thought
SSRIs or SNRIs: one isn't better than the other—it’s about what fits your brain chemistry, comfort, and functional goals.
If you're curious whether an SNRI might be a better fit, I'm here to walk through it with you—step by step.
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Rooted in Serenity Behavioral Health offers telepsychiatric care for adults navigating anxiety, depression, ADHD, trauma, and medication support with empathy and expertise.
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Founder of Rooted in Serenity Behavioral Health LLC, offering telepsychiatry services across Connecticut for adults navigating anxiety, ADHD, trauma, and more.
