Cymbalta Side Effects

Generic name: duloxetine

Medically reviewed by Drugs.com. Last updated on Sep 23, 2024.

Note: This document provides detailed information about Cymbalta Side Effects associated with duloxetine. Some dosage forms listed on this page may not apply specifically to the brand name Cymbalta.

Applies to duloxetine: oral capsule delayed release.

Common side effects of Cymbalta

Some side effects of duloxetine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Serious side effects of Cymbalta

Along with its needed effects, duloxetine (the active ingredient contained in Cymbalta) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking duloxetine:

Get emergency help immediately if any of the following symptoms of overdose occur while taking duloxetine:

Symptoms of overdose

• agitation
• diarrhea
• fever
• loss of bladder control
• muscle spasm or jerking of all extremities
• overactive reflexes
• poor coordination
• restlessness
• shivering
• sleepiness or unusual drowsiness
• sudden loss of consciousness
• sweating
• talking or acting with excitement you cannot control
• trembling or shaking
• twitching
• unusual tiredness or weakness
• vomiting

Precautions

It is important that your doctor check your progress at regular visits to allow for changes in your dose and to help prevent any unwanted effects.

Do not take duloxetine with a monoamine oxidase (MAO) inhibitor (eg, isocarboxazid [Marplan®], phenelzine [Nardil®], selegiline [Eldepryl®], or tranylcypromine [Parnate®]) in the past 2 weeks. Do not start taking an MAO inhibitor within 5 days of stopping duloxetine. If you do, you may develop confusion, agitation, restlessness, stomach or intestinal symptoms, sudden high body temperature, extremely high blood pressure, or severe convulsions. Ask your doctor if you are not sure if you take an MAOI, including linezolid (Zyvox®) or methylene blue injection.

Duloxetine may cause some teenagers and young adults to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. Some people may have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. If you or your caregiver notice any of these unwanted effects, tell your doctor right away. Let the doctor know if you or anyone in your family has bipolar disorder (manic-depressive) or has tried to commit suicide.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Duloxetine may cause a serious condition called serotonin syndrome if taken together with some medicines. Do not use duloxetine with buspirone (Buspar®), fentanyl (Abstral®, Duragesic®), lithium (Eskalith®, Lithobid®), tryptophan, St. John's wort, amphetamines, or some pain or migraine medicines (eg, meperidine, methadone, rizatriptan, sumatriptan, tramadol, Demerol®, Methadose®, Frova®, Imitrex®, Maxalt®, Relpax®, Ultram®, Zomig®). Check with your doctor first before using any other medicines with duloxetine.

This medicine may increase your risk for bleeding problems. Make sure your doctor knows if you are also taking other medicines that thin the blood, such as aspirin, NSAID pain medicines (eg, ibuprofen, naproxen, Advil®, Aleve®, Celebrex®, or Motrin®) or warfarin (Coumadin®).

Serious skin reactions (eg, erythema multiforme, Stevens-Johnson syndrome) can occur during treatment with this medicine. Check with your doctor right away if you have blistering, peeling, or loosening of the skin, chills, cough, diarrhea, itching, joint or muscle pain, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, or unusual tiredness or weakness while you are using this medicine.

Do not suddenly Stop taking duloxetine without checking first with your doctor. If you have been instructed to stop taking duloxetine, ask your doctor how to slowly decrease the dose. This will decrease your chance of having withdrawal symptoms such as dizziness, nausea, headaches, vomiting, increased sweating, irritability, nightmares, trouble with sleeping, or prickling or tingling feelings.

This medicine may affect blood sugar levels. If you are diabetic and notice a change in the results of your blood or urine sugar tests, check with your doctor.

This medicine may cause blurred vision, dizziness, drowsiness, trouble with thinking, or trouble with controlling body movements, which may lead to falls, fractures, or other injuries. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert or able to see clearly. You may also feel lightheaded or you may fall or faint when getting up suddenly from a lying or sitting position, so get up slowly. If these symptoms are bothering you or keeping you from doing your daily activities, tell your doctor right away.

You will need to measure your blood pressure before starting this medicine and while you are using it. If you notice any change to your recommended blood pressure, call your doctor right away. If you have questions about this, talk to your doctor.

Hyponatremia (low sodium in the blood) may occur with this medicine. Check with your doctor right away if you have confusion, decreased urine output, difficulty concentrating, fast or irregular heartbeat, headaches, memory problems, nausea or vomiting, swelling of the face, ankles, or hands, trouble breathing, or unusual tiredness or weakness.

This medicine may cause sexual problems. Check with your doctor right away if you have decreased interest in sexual intercourse, inability to have or keep an erection, or loss in sexual ability, desire, drive, or performance.

Avoid smoking while you are using this medicine. If you have any questions about this, check with your doctor.

For healthcare professionals

Applies to duloxetine: oral delayed release capsule.

General adverse events

The most commonly reported side effects included nausea, somnolence, headache, and dizziness.^[Ref]

Gastrointestinal

• Very common (10% or more): Nausea (up to 30%), constipation (up to 15%), dry mouth (up to 15%), vomiting (up to 15%), abdominal pain (up to 13%), diarrhea (up to 13%)
• Common (1% to 10%): Dyspepsia, flatulence, loose stools, oral paresthesia, stomach discomfort, viral gastroenteritis/gastroenteritis
• Uncommon (0.1% to 1%): Dysphagia, eructation, gastritis, gastrointestinal bleeding/hemorrhage, halitosis, stomatitis
• Rare (0.01% to 0.1%): Gastric ulcer, hematochezia, microscopic colitis
• Frequency not reported: Abdominal discomfort, abdominal tenderness, gastrointestinal pain, lower abdominal pain, upper abdominal pain
• Postmarketing reports: Pancreatitis, unspecified colitis^[Ref]

Abdominal pain more commonly occurred in pediatric patients.

Constipation occurred most frequently in patients given 60 mg orally 2 times a day (N=225); the side effect occurred in 11% of patients given 60 mg orally once a day, and in 5% of patients given 20 mg orally once a day.

Diarrhea occurred most frequently in patients given 20 mg orally once a day (N=115); the side effect occurred in 7% of patients given 60 mg orally 2 times a day, and in 11% of patients given 60 mg orally once a day.

Dry mouth occurred most frequently in patients in patients with generalized anxiety disorder (GAD) or major depressive disorder (MDD) compared to placebo (N=2995).

Nausea occurred most frequently in patients given 60 mg orally 2 times a day (N=225); the side effect occurred in 22% of patients given 60 mg orally once a day, and in 14% of patients given 20 mg orally once a day.

Vomiting occurred more frequently in patients 13 to 17 years of age with fibromyalgia.^[Ref]

Nervous system

• Very common (10% or more): Somnolence (up to 21%), headache (up to 18%), dizziness (up to 17%)
• Common (1% to 10%): Dysgeusia, facial hypoesthesia, hypoesthesia, lethargy, paresthesia, psychomotor agitation, tremor, vertigo
• Uncommon (0.1% to 1%): Akathisia, attention disturbance, dyskinesia, gait disturbance, myoclonus, poor quality sleep, restless legs syndrome, syncope
• Rare (0.01% to 0.1%): Convulsion, dysarthria, extrapyramidal disorder, psychomotor restlessness, serotonin syndrome
• Very rare (less than 0.01%): Electric shock-like sensation, seizures
• Frequency not reported: Hypersomnia, psychomotor hyperactivity, sedation, sensory disturbances
• Postmarketing reports: Intracerebral bleeding^[Ref]

Dizziness occurred most frequently in patients given 60 mg orally 2 times a day (N=225); the side effect occurred in 14% of patients given 60 mg orally once a day, and in 6% of patients given 20 mg orally once a day.

Headache more commonly occurred in pediatric patients.

Convulsion and seizures were reported during treatment discontinuation.

Somnolence occurred most frequently in patients given 60 mg orally 2 times a day (N=225); the side effect occurred in 15% of patients given 60 mg orally once a day, and in 7% of patients given 20 mg orally once a day.

Syncope was reported, especially during treatment initiation.^[Ref]

Metabolic

• Very common (10% or more): Decreased weight (up to 16%), decreased appetite (up to 16%)
• Common (1% to 10%): Anorexia, increased weight
• Uncommon (0.1% to 1%): Blood potassium increased, dehydration, hyperglycemia, hyperlipidemia, increased blood cholesterol, thirst
• Rare (0.01% to 0.1%): Dyslipidemia, hyponatremia^[Ref]

Decreased appetite occurred more frequently in patients 13 to 17 years of age with fibromyalgia.

Decreased weight of at least 3.5% occurred more frequently in patients 7 to 17 years of age with GAD and/or MDD.

Hyperglycemia was more commonly reported in patients with diabetes.^[Ref]

Respiratory

• Very common (10% or more): Nasopharyngitis (up to 14%)
• Common (1% to 10%): Cough, oropharyngeal pain, pharyngolaryngeal pain, upper respiratory tract infection, yawning
• Uncommon (0.1% to 1%): Epistaxis, throat tightness
• Rare (0.01% to 0.1%): Eosinophilic pneumonia, interstitial lung disease^[Ref]

Nasopharyngitis occurred more frequently in patients 13 to 17 years of age with fibromyalgia.^[Ref]

Psychiatric

• Very common (10% or more): Insomnia (up to 13%)
• Common (1% to 10%): Abnormal dreams, abnormal orgasm, agitation, anorgasmia, anxiety, decreased libido/decreased sex drive, restlessness, sleep disorder, tension
• Uncommon (0.1% to 1%): Apathy, bruxism, confusional state, disorientation, irritability, mood swings, nervousness, nightmares, suicidal ideation, suicide attempt
• Rare (0.01% to 0.1%): Aggression, anger, completed suicide, hallucinations, mania, suicidal behavior
• Frequency not reported: Activation of hypomania, early morning awakening, initial insomnia, intense dreams, loss of libido, middle insomnia, sleep disturbances, terminal insomnia^[Ref]

Aggression and/or anger usually occurred initially or after stopping treatment.

Insomnia occurred most frequently in patients given 60 mg orally 2 times a day (N=225); the side effect occurred in 8% of patients given 60 mg orally once a day, and in 9% of patients given 20 mg orally once a day.^[Ref]

Other

• Very common (10% or more): Fatigue (up to 12%)
• Common (1% to 10%): Asthenia, chills, falls, feeling jittery, pyrexia, rigors, tinnitus
• Uncommon (0.1% to 1%): Ear pain, feeling abnormal, feeling cold/hot, malaise
• Frequency not reported: Clinically important drug interactions^[Ref]

Fatigue occurred most frequently in patients given 60 mg orally 2 times a day (N=225); the side effect occurred in 10% of patients given 60 mg orally once a day, and in 2% of patients given 20 mg orally once a day.

Falls were more common in patients 65 years and older.

Tinnitus was reported during treatment discontinuation.^[Ref]

Genitourinary

• Common (1% to 10%): Ejaculation delayed, ejaculation disorder, erectile dysfunction, polyuria, urinary frequency
• Uncommon (0.1% to 1%): Abnormal urine odor, dysuria, ejaculation dysfunction, ejaculation failure, menopausal symptoms, micturition urgency, nocturia, sexual dysfunction, testicular pain, urinary hesitation, urinary retention
• Rare (0.01% to 0.1%): Decreased urine flow, menstrual disorder
• Very rare (less than 0.01%): Galactorrhea, gynecological bleeding
• Frequency not reported: Genital hypoesthesia, problems getting/keeping an erection^[Ref]

Musculoskeletal

• Common (1% to 10%): Muscle cramp, muscle spasms, musculoskeletal pain, myalgia, neck pain
• Uncommon (0.1% to 1%): Blood creatine phosphokinase increased, muscle tightness, muscle twitching, musculoskeletal stiffness, trismus
• Postmarketing reports: Rhabdomyolysis^[Ref]

Cardiovascular

• Common (1% to 10%): Blood pressure increased, flushing/hot flush, palpitations
• Uncommon (0.1% to 1%): Atrial fibrillation, chest pain, hypertension, increased diastolic blood pressure, increased systolic blood pressure, myocardial infarction, orthostatic hypertension, peripheral coldness, supraventricular arrhythmia, tachycardia, Takotsubo cardiomyopathy
• Rare (0.01% to 0.1%): Hypertensive crisis, supraventricular fibrillation
• Frequency not reported: Diastolic hypertension, essential hypertension, labile hypertension, pulse increased, secondary hypertension, systolic hypertension
• Postmarketing reports: Cardiac events, ventricular arrhythmias^[Ref]

Orthostatic hypotension was reported, especially during treatment initiation.^[Ref]

Dermatologic

• Common (1% to 10%): Hyperhidrosis/increased sweating, pruritus, rash
• Uncommon (0.1% to 1%): Cold sweat, contact dermatitis, erythema, night sweats, photosensitivity reaction, urticaria
• Rare (0.01% to 0.1%): Ecchymosis
• Very rare (less than 0.01%): Cutaneous vasculitis, contusion, Stevens-Johnson syndrome
• Frequency not reported: Severe skin reactions, subcutaneous tissue disorder^[Ref]

Cutaneous vasculitis was sometimes associated with systemic involvement.^[Ref]

Ocular

• Common (1% to 10%): Blurred vision
• Uncommon (0.1% to 1%): Diplopia, dry eye, mydriasis, visual impairment
• Rare (0.01% to 0.1%): Glaucoma
• Frequency not reported: Angle-closure glaucoma^[Ref]

Immunologic

• Common (1% to 10%): Influenza
• Uncommon (0.1% to 1%): Laryngitis^[Ref]

Hepatic

• Uncommon (0.1% to 1%): Acute liver injury, ALT elevation, alkaline phosphatase elevation, AST elevation, blood bilirubin increased, elevated liver enzymes, GGT increased, hepatitis
• Rare (0.01% to 0.1%): Hepatic failure, jaundice
• Frequency not reported: Hepatotoxicity, liver failure^[Ref]

Endocrine

• Uncommon (0.1% to 1%): Hypothyroidism
• Rare (0.01% to 0.1%): Hyperprolactinemia, syndrome of inappropriate antidiuretic hormone secretion (SIADH)^[Ref]

Hypersensitivity

• Uncommon (0.1% to 1%): Hypersensitivity disorder
• Rare (0.01% to 0.1%): Anaphylactic reaction
• Very rare (less than 0.01%): Angioneurotic edema, hypersensitivity^[Ref]

Hematologic

• Uncommon (0.1% to 1%): Increased tendency to bruise
• Postmarketing reports: Abnormal bleeding events, blood dyscrasias^[Ref]

Renal

• Postmarketing reports: Renal dysfunction^[Ref]

See also:

Frequently asked questions

• 8 Cymbalta Side Effects: Should I be Concerned?
• What helps with Cymbalta withdrawal symptoms?
• How to sleep while taking Cymbalta?
• Does Cymbalta cause weight gain?
• How long does it take for Cymbalta to work?
• What do Cymbalta brain zaps feel like?
• Can I take Cymbalta (duloxetine) and Trintellix (vortioxetine) together?
• SSRIs vs SNRIs - What's the difference between them?

Further information

Cymbalta side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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