Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Cymbalta (Duloxetine). If you are concerned about side effects, discuss the risks and benefits of Cymbalta (Duloxetine) with your doctor.

The following side effects have been reported by at least 1% of people taking Cymbalta (Duloxetine). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• changes in sexual desire or ability
• Constipation
• decreased appetite
• Diarrhea
• difficulty sleeping
• dizziness
• Dry Mouth
• fatigue
• headache
• increased sweating
• nausea
• restlessness (feeling like you need to keep moving)
• sleepiness
• vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• hallucinations (seeing or hearing things that are not there)
• inability to pass urine
• new or worsening emotional or behavioural problems
• overactive thoughts or behaviour
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don’t stop bleeding)
• skin rash or Hives (with no other symptoms)
• symptoms of glaucoma (e.g., blurred vision, seeing halos of bright colours around lights, red eyes, increased pressure in your eyes, eye pain or discomfort)
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
• symptoms of liver problems (e.g., nausea, vomiting, or loss of appetite, combined with yellow skin or eyes, dark urine, or itching)
• symptoms of low sodium levels in the blood (e.g., tiredness, weakness, and confusion combined with achy, stiff, or uncoordinated muscles)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizures
• signs of an allergic reaction (e.g., shortness of breath or difficulty breathing; hives, itching or rash; swelling of the eyes, mouth, lips, or throat)
• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with Fever or discomfort
• symptoms of serotonin syndrome or neuroleptic malignant syndrome (e.g., experiencing most or all of the following: confusion, restlessness, extreme agitation, high fever, sweating, shivering, shaking, hallucinations, fast heartbeat, and sudden muscle jerking)
• thoughts of suicide or self-harm
• vision changes or eye pain

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Cymbalta (Duloxetine).

30 mg
Each delayed-release capsule with opaque white body and opaque blue cap, imprinted "30 mg" on the body and "9543" on the cap, contains 30 mg of Cymbalta (Duloxetine). Nonmedicinal ingredients: FD&C Blue No. 2, gelatin, hydroxypropyl methylcellulose, hydroxypropyl methylcellulose acetate succinate, sodium lauryl sulfate, sucrose, sugar spheres, talc, titanium dioxide, and triethyl citrate.

60 mg
Each delayed-release capsule with opaque green body and opaque blue cap, imprinted "60 mg" on the body and "9542" on the cap, contains 60 mg of Cymbalta (Duloxetine). Nonmedicinal ingredients: FD&C Blue No. 2, gelatin, hydroxypropyl methylcellulose, hydroxypropyl methylcellulose acetate succinate, sodium lauryl sulfate, sucrose, sugar spheres, talc, titanium dioxide, triethyl citrate, and yellow iron oxide.

Do not take Cymbalta (Duloxetine) if you:

• are allergic to Cymbalta (Duloxetine) or any ingredients of the medication
• have liver disease causing reduced liver function
• have severely reduced kidney function
• have uncontrolled narrow-angle Glaucoma
• are taking Fluvoxamine and other medications with a similar effect on drug metabolism in the liver (check with your pharmacist)
• are taking MAO inhibitors (e.g., Phenelzine, Tranylcypromine, Linezolid, methylene blue) or have taken a MAO inhibitor within 2 weeks of starting Cymbalta (Duloxetine)
• are taking quinolone medications (e.g., ciprofloxacin, Norfloxacin)
• are taking thioridazine

There may be an interaction between Cymbalta (Duloxetine) and any of the following:

• Abiraterone acetate
• acetylsalicylic acid (ASA)
• alcohol
• Aldesleukin
• Aliskiren
• alpha-agonists (e.g., Clonidine, methyldopa)
• alpha/beta-agonists (e.g., Epinephrine, norepinephrine)
• alpha-blockers (e.g., Alfuzosin, Doxazosin, Tamsulosin)
• amphetamines (e.g., Dextroamphetamine, Lisdexamfetamine)
• angiotensin-converting enzyme inhibitors (ACEIs; Captopril, Enalapril, Ramipril)
• angiotensin receptor blockers (ARBs; e.g., Candesartan, Irbesartan, Losartan)
• antiarrhythmics (e.g., Amiodarone, Dipyridamole, Flecainide, Propafenone, quinidine)
• antipsychotics (e.g., Chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• Apixaban
• Atomoxetine
• beta-adrenergic blockers (e.g., Atenolol, Propranolol, Sotalol)
• brimonidine
• Bromocriptine
• Bupropion
• Buspirone
• Cabergoline
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• cannabis
• Carbamazepine
• Celecoxib
• chloroquine
• Chlorpheniramine
• Cinacalcet
• Clopidogrel
• Cyclobenzaprine
• Cyproterone
• dabigatran
• Deferasirox
• delavirdine
• Dextromethorphan
• diuretics (water pills; e.g., Furosemide, Hydrochlorothiazide, triamterene)
• Doxorubicin
• Edoxaban
• Eliglustat
• ergot alkaloids (e.g., ergotamine, Dihydroergotamine)
• Fesoterodine
• glucosamine
• Guanfacine
• Heparin
• Hydralazine
• linezolid
• lithium
• lopinavir
• low-molecular-weight heparins (e.g., Dalteparin, Enoxaparin, Tinzaparin)
• Methadone
• methoxsalen
• methylene blue
• Metoclopramide
• Minoxidil
• Mirabegron
• Mirtazapine
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, phenelzine, Rasagiline, Selegiline, tranylcypromine)
• Meperidine
• Methylphenidate
• multivitamins with minerals
• nitrates (e.g., Nitroglycerin, isosorbide dinitrate, isosorbide mononitrate)
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen, naproxen, ketoprofen)
• omega-3 fatty acids
• Paclitaxel
• Phenobarbital
• Pramipexole
• Prasugrel
• Primaquine
• primidone
• Pseudoephedrine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, norfloxacin)
• rifampin
• ritonavir
• Rivaroxaban
• Ropinirole
• St. John's wort
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin antagonists (anti-emetic medications; e.g., Granisetron, Ondansetron)
• other serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., Desvenlafaxine, Venlafaxine)
• Tamoxifen
• Tapentadol
• Ticagrelor
• Ticlopidine
• tobacco (smoked)
• tolcapone
• Tramadol
• Trazodone
• tricyclic antidepressants (e.g., Imipramine, Amitriptyline, Nortriptyline, Desipramine)
• "triptan" medications (e.g., Sumatriptan, Rizatriptan)
• Tryptophan
• tyrosine kinase inhibitors (e.g., Dasatinib, imatinib, Nilotinib, Vemurafenib)
• vitamin E
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Cymbalta (Duloxetine). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Cymbalta (Duloxetine).

Bleeding: Cymbalta (Duloxetine) may increase the risk of bleeding, especially if you are also taking medications such as acetylsalicylic acid (Asa), nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., Ibuprofen, Naproxen, Ketoprofen), or Warfarin. If you experience easy bruising, pinpoint-sized red spots on the skin, or unusual bleeding while taking Cymbalta (Duloxetine), contact your doctor immediately.

Blood pressure and heart rate: Cymbalta (Duloxetine) may cause an increase in blood pressure or heart rate. Your doctor will monitor your blood pressure and heart rate before starting Cymbalta (Duloxetine) and periodically while you are taking Cymbalta (Duloxetine). If you have high blood pressure or other types of heart disease, discuss with your doctor how Cymbalta (Duloxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Cymbalta (Duloxetine), and whether any special monitoring is needed.

Bone fractures: Cymbalta (Duloxetine) may increase your risk of breaking a bone, especially if you are a senior, have Osteoporosis, or have other risk factors for bone fractures. Take extra care to avoid falling by sitting or lying down if you feel dizzy or lightheaded. Contact your doctor if you experience dizziness or lightheadedness frequently.

Diabetes: Cymbalta (Duloxetine) may worsen blood sugar control in some people who have diabetes. If you have diabetes, monitor your blood sugar closely and report any changes to your doctor.

If you are at risk for developing diabetes, discuss with your doctor how Cymbalta (Duloxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Cymbalta (Duloxetine), and whether any special monitoring is needed.

Drowsiness/reduced alertness: Cymbalta (Duloxetine) may affect judgment, thinking, or physical abilities and may cause drowsiness or dizziness. Avoid driving, operating machinery, or performing other hazardous tasks until you have determined how Cymbalta (Duloxetine) affects you.

Glaucoma: Cymbalta (Duloxetine) may cause the symptoms of glaucoma (increased pressure in the eye) to become worse. If you have controlled narrow-angle glaucoma, discuss with your doctor how Cymbalta (Duloxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Cymbalta (Duloxetine), and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking Cymbalta (Duloxetine).

Kidney function: Cymbalta (Duloxetine) is not recommended for people with severe kidney problems. If you have kidney problems, discuss with your doctor how Cymbalta (Duloxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Cymbalta (Duloxetine), and whether any special monitoring is needed.

Liver function: Decreased liver function or liver disease can cause Cymbalta (Duloxetine) to build up in the body, causing side effects. If you have liver problems or consume substantial amounts of alcohol, discuss with your doctor how Cymbalta (Duloxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Cymbalta (Duloxetine), and whether any special monitoring is needed. Cymbalta (Duloxetine) may also cause liver problems. If you experience nausea, abdominal pain, or yellowing of the skin or eyes while taking Cymbalta (Duloxetine), contact your doctor immediately.

Seizures: If you have a seizure disorder, discuss with your doctor how Cymbalta (Duloxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Cymbalta (Duloxetine), and whether any special monitoring is needed.

Serotonin syndrome/neuroleptic malignant syndrome: Severe reactions are possible when Cymbalta (Duloxetine) is combined with other medications that act on serotonin, such as tricyclic antidepressants and certain migraine medications. These combinations must be avoided. Symptoms of a reaction may include muscle rigidity and spasms, difficulty moving, and changes in mental state including delirium and agitation. Coma and death are possible.

If you are taking antidepressants, discuss with your doctor how Cymbalta (Duloxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Cymbalta (Duloxetine), and whether any special monitoring is needed.

Slowed stomach emptying: If you have a condition that slows emptying from the stomach (e.g., diabetes), discuss with your doctor how Cymbalta (Duloxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Cymbalta (Duloxetine), and whether any special monitoring is needed.

Stopping the medication: Stopping Cymbalta (Duloxetine) suddenly may lead to side effects such as dizziness, abnormal dreams, difficulty sleeping, numbness or tingling sensations, irritability, anxiety, nausea, vomiting, diarrhea, sweating, muscle pain, or other symptoms. Stopping Cymbalta (Duloxetine) gradually as directed by your doctor can minimize these effects. If you are thinking of stopping the medication, check with your doctor first.

Sucrose: Cymbalta (Duloxetine) contains sucrose. If you have a rare hereditary problem of fructose intolerance, glucose-galactose malabsorption, or sucrose metabolism, you should not take Cymbalta (Duloxetine).

Suicidal or agitated behaviour: People taking Cymbalta (Duloxetine) may feel agitated (restless, anxious, aggressive, emotional, and feeling not like themselves), or they may want to hurt themselves or others. If you experience these side effects or notice them in a family member who is taking Cymbalta (Duloxetine), contact your doctor immediately. Your doctor will monitor you closely for these side effects while you are taking Cymbalta (Duloxetine).

Urinary tract symptoms: Some people who take Cymbalta (Duloxetine) experience difficulty starting urine flow or emptying the bladder. If you notice these changes, contact your doctor.

Pregnancy: It has been reported that babies born to women who took medications similar to Cymbalta (Duloxetine) during the last trimester of their pregnancy may experience adverse effects (such as breathing problems, seizures, trouble feeding, jitteriness, irritability, and constant crying). Women who take Cymbalta (Duloxetine) during pregnancy may be at increased risk of bleeding after childbirth. Cymbalta (Duloxetine) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Cymbalta (Duloxetine), contact your doctor immediately.

Breast-feeding: Cymbalta (Duloxetine) passes into breast milk. If you are a breast-feeding mother and are taking Cymbalta (Duloxetine), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children and adolescents: The safety and effectiveness of Cymbalta (Duloxetine) have not been established for children. Children under 18 years old are at an increased risk of suicidal thoughts or behaviour if they take Cymbalta (Duloxetine).