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

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