Is it safe to use duloxetine and Cymbalta (duloxetine) together?

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Last updated: November 8, 2025View editorial policy

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Do Not Use Duloxetine and Cymbalta Together

Duloxetine and Cymbalta are the exact same medication—using them together would constitute a dangerous double dose. Cymbalta is simply the brand name for duloxetine, so taking both simultaneously means you are taking twice the intended amount of the same drug 1.

Why This Is Dangerous

  • The FDA explicitly warns against taking duloxetine with any other medicine that contains duloxetine 1
  • Taking a double dose significantly increases the risk of serious adverse effects including:
    • Serotonin syndrome (a potentially life-threatening condition with symptoms including tremor, delirium, neuromuscular rigidity, and hyperthermia) 2, 1
    • Severe liver injury 1, 3
    • Increased blood pressure and cardiovascular complications 1
    • Severe gastrointestinal symptoms (nausea, vomiting) 2, 4

Fatal Overdose Risk

  • A case report documented a fatal overdose involving SNRIs (the drug class that includes duloxetine), demonstrating that excessive doses can progress to serotonin syndrome and death within approximately 6 hours 5
  • While duloxetine has a relatively high therapeutic-to-toxicity ratio under normal dosing, intentional or accidental overdose can be lethal 5, 4

Correct Dosing Guidelines

  • The typical therapeutic dose of duloxetine is 60 mg once daily 2, 6
  • The maximum recommended dose is 120 mg/day (60 mg twice daily) 6, 1
  • Duloxetine is approved for multiple conditions including depression, anxiety, diabetic neuropathy, fibromyalgia, and chronic musculoskeletal pain 2, 6, 1

What To Do If This Error Occurred

  • Stop taking one of the medications immediately and contact your healthcare provider or call poison control at 1-800-222-1222 1
  • If serious symptoms develop (confusion, rapid heart rate, high fever, muscle rigidity, agitation), seek emergency medical attention 1
  • Do not abruptly stop duloxetine after prolonged use without medical supervision, as this can cause withdrawal symptoms 6, 1

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Adverse reactions to duloxetine in depression.

Expert opinion on drug safety, 2011

Research

Safety and adverse event profile of duloxetine.

Expert opinion on drug safety, 2005

Research

Fatal overdose with a combination of SNRIs venlafaxine and duloxetine.

Forensic science, medicine, and pathology, 2019

Guideline

Duloxetine Scheduling and Clinical Applications

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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