There is a major drug interaction between Cymbalta (duloxetine) and Trintellix (vortioxetine). Taking these medications together increases the risk of a rare condition called serotonin syndrome which is caused by an accumulation of too much serotonin.

Symptoms of serotonin syndrome include:

• blurred vision,
• confusion,
• diarrhea,
• excessive sweating,
• extreme changes in blood pressure,
• fever,
• hallucination,
• incoordination,
• increased heart rate,
• muscle spasm or stiffness,
• nausea,
• seizure,
• shivering or shaking,
• stomach cramps,
• tremor,
• vomiting.

If you are taking these two medications together and have any of these symptoms you should seek immediate medical attention. Severe cases of serotonin syndrome may cause coma and even death.

What if I have been prescribed to take Cymbalta and Trintellix together?

• If you are feeling well and have none of the symptoms of serotonin syndrome, then you should not stop taking any of your medications, without talking to your doctor.
• Your doctor may be aware of the interaction but with their professional judgement may have determined this is the best medication treatment plan for you.
• You should be monitored closely for any signs of serotonin syndrome.
• If you have any concerns or questions about your treatment plan you should talk to your doctor.

When can serotonin syndrome occur with Cymbalta and Trintellix?

• Serotonin syndrome can occur when taking Cymbalta or Trintellix alone and may become apparent when your dose is increased.
• Sometimes serotonin syndrome occurs when changing from one serotonergic medication to another, some experts suggest a 3 week washout period after stopping vortioxetine before starting another serotonergic medication.
• Serotonin syndrome is more likely to occur when you are already on either Cymbalta or Trintellix and then you have the other medicine added to your treatment regime.
• It is important to be monitored for emerging serotonin syndrome if you have either of your medication doses increased.

Bottom line:

• There is a major interaction between Duloxetine and Vortioxetine
• The interaction increases the risk of a rare but serious condition called serotonin syndrome.
• In some cases these two medications may be prescribed together, only when the prescriber deems the benefit outweighs the risk, however patients must be closely monitored for symptoms of serotonin syndrome.