See also Warning section.
Nausea, dry mouth, constipation, loss of appetite, tiredness, drowsiness, or increased sweating may occur. If any of these effects persist or worsen, tell your doctor promptly.
Dizziness or lightheadedness may occur, especially when you first start or increase your dose of this drug. To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Duloxetine may increase your blood pressure. Check your blood pressure regularly and tell your doctor of any high results.
Tell your doctor right away if any of these serious side effects occur: confusion, easy bruising/bleeding, decreased interest in sex, changes in sexual ability, muscle cramps/weakness, shaking (tremor), difficulty urinating, unusual decrease in the amount of urine, signs of liver problems (such as stomach/abdominal pain, persistent nausea, vomiting, yellowing eyes/skin, dark urine).
Get medical help right away if any of these rare but serious side effects occur: black/bloody stools, vomit that looks like coffee grounds, seizure.
This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing, skin blisters, mouth sores.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.