Milnacipran: SNRI for Fibromyalgia and Depression
Milnacipran (Ixel, Savella) is a serotonin-norepinephrine reuptake inhibitor (SNRI) with a relatively greater effect on norepinephrine reuptake compared to serotonin, distinguishing it from duloxetine and venlafaxine.
Approved for major depressive disorder in Europe (Ixel) and for fibromyalgia in the USA (Savella). The norepinephrine-predominant profile is thought to contribute to pain modulation.
Mechanism of Action
Inhibits reuptake of both serotonin and norepinephrine at presynaptic transporters, with approximately 3:1 preference for norepinephrine. This is opposite to most other SNRIs. Norepinephrine reuptake inhibition contributes to descending pain inhibition in fibromyalgia.
Indications & Use
Major depressive disorder (EU/Asia), fibromyalgia (USA, Japan). Not FDA-approved for MDD. Off-label: chronic pain syndromes, stress urinary incontinence (in some countries).
Dosage
MDD: 50 mg twice daily (range 100–200 mg/day). Fibromyalgia: start 12.5 mg/day, titrate over 1–2 weeks to 50 mg twice daily. Dose reduction required in renal impairment (GFR <30 mL/min).
Side Effects
Common: nausea, palpitations, hot flushes, hyperhidrosis, hypertension, dysuria (due to noradrenergic effects on lower urinary tract). Fewer sexual side effects than SSRIs. No significant weight gain.
Drug Interactions
MAOIs: contraindicated — serotonin syndrome. Clonidine: milnacipran may reduce clonidine's antihypertensive effect. Triptans: serotonin syndrome risk. Strong noradrenergic drugs: additive effects. Monitor blood pressure.
Contraindications
Concurrent MAOI use (or within 14 days), uncontrolled narrow-angle glaucoma, significant cardiovascular disease, severe renal impairment without dose adjustment.
Frequently Asked Questions
How does milnacipran differ from duloxetine for fibromyalgia?
Both are SNRIs approved or used for fibromyalgia. Milnacipran has a higher NE:5-HT ratio (~3:1 vs. duloxetine's ~1:10), which may offer different pain modulation profiles. Duloxetine is also approved for diabetic neuropathy; milnacipran is not.
Does milnacipran help with pain in fibromyalgia?
Yes — in clinical trials, milnacipran significantly reduced pain scores and improved function. About 30-40% of patients achieve a ≥30% reduction in pain. It does not cure fibromyalgia but is part of multimodal management.
Can milnacipran raise blood pressure?
Yes — due to noradrenergic activity, milnacipran can elevate heart rate and blood pressure. Blood pressure should be monitored, particularly during dose titration, and it should be used with caution in hypertensive patients.
References
- EMA Ixel SPC 2023
- Clauw DJ: Fibromyalgia. JAMA 2014
- Arnold LM et al. Arthritis Rheum 2010
Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice.