Handouts · Medications
SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors)
Includes venlafaxine, desvenlafaxine, duloxetine, and levomilnacipran. Used for depression, anxiety, and some chronic pain.
What This Group Is
SNRIs raise two brain chemicals — serotonin and norepinephrine — which lift mood and energy and can ease nerve pain.
They treat depression, anxiety, and conditions like fibromyalgia or diabetic nerve pain. Full effect takes 4–6 weeks.
How to Take It
Take with food to cut down on nausea. Swallow extended-release capsules whole — do not crush.
Do not stop suddenly. Venlafaxine especially can cause dizziness, “brain zaps,” and flu-like feelings if missed — always taper with your prescriber.
Black Box Warning
Like all antidepressants, SNRIs can rarely raise suicidal thoughts in people under 25, especially early on.
Watch closely in the first weeks and after dose changes; call right away if dark thoughts or agitation worsen.
Common (Usually Mild) Side Effects
- Nausea, dry mouth, constipation.
- Sweating and feeling warm.
- Sexual side effects.
- Trouble sleeping or feeling jittery.
Serious — Call Us or Seek Care
- Raised blood pressure (more likely at higher doses of venlafaxine).
- Serotonin syndrome: agitation, sweating, shivering, fast heartbeat.
- Low sodium (confusion, weakness) — more common in older adults.
- Liver problems with duloxetine — yellowing skin, dark urine, belly pain.
Alcohol & Interactions
Avoid heavy alcohol — with duloxetine it raises the risk of liver injury, and it worsens depression.
Tell us about other serotonin drugs, blood thinners, and NSAIDs.
Monitoring
We recommend checking your blood pressure before and during treatment, especially on venlafaxine.
No routine labs otherwise; sodium may be checked in older adults if symptoms appear.