What is Cymbalta® and what does it treat?
Duloxetine is a serotonin and norepinephrine reuptake inhibitor (or “SNRI”) that is used to treat major depressive disorder (also, major depression or MDD). In addition, duloxetine is effective, and FDA approved, for the treatment of diabetic peripheral neuropathy (DPN). Key elements to both illnesses are that untreated symptoms remain in place over long periods of time, and that while untreated the person’s functioning in day–to–day life is significantly decreased.
Major depression, or depression, is when a person experiences several of the following symptoms at the same time: “low” or depressed mood (for example, sad, empty, tearful), decreased interest in most or all activities, changes in appetite, changes in sleep (usually poor sleep), loss of energy, feeling worthless/guilty/ hopeless/ helpless, difficulty concentrating, thoughts of death (suicidal thinking).
Diabetic peripheral neuropathy is characterized by a burning or tingling sensation, usually in the hands or feet.
Duloxetine may be used for other pain or mood disorders such as fibromyalgia, chronic pain, and stress incontinence as determined by your health care provider.
What is the most important information I should know about Cymbalta®?
- After starting an SNRI, symptoms gradually decrease over a period of at least a few weeks. Once symptoms are under control, MDD and DPN usually require long-term treatment. Only your healthcare provider can determine the length of duloxetine treatment that is right for you.
- Do not stop taking duloxetine or change your dose without talking with your healthcare provider first.
- Stopping duloxetine abruptly can result in one or more of the following withdrawal effects: irritability, nausea, dizziness, vomiting, nightmares, headache, and paresthesias.
- Patients with depression or other mental illnesses often think about, or attempt, suicide. Closely watch anyone taking antidepressants, especially early in treatment or when the dose is changed. Patients who become irritable or anxious, or have new or increased thoughts of suicide or other changes in mood or behavior (or their care givers) should contact their healthcare professional right away.
Children(18 years or younger) taking antidepressants experience suicidal thoughts or actions in about 1 out of every 50 who are depressed. Although duloxetine is prescribed for children, the FDA has not approved duloxetine for use in children.
Adults: several recent scientific publications report the possibility of an increased risk for suicidal behavior in adults who are being treated with antidepressant medications. Even before these reports became available, FDA began a complete review of all available data to determine whether there is an increased risk of suicidal thinking or behavior in adults being treated with antidepressant medications. It is expected that this review will take a year or longer to complete. In the meantime, FDA is highlighting that adults being treated with antidepressant medication, particularly those being treated for depression, should be watched closely for worsening of depression and for increased suicidal thinking or behavior, particularly during the first few weeks of treatment and after a dosage change.
- Because depression is also a part of Bipolar illness, people who take antidepressants may be at risk for “switching” from depression into mania. Symptoms of mania include “high” or irritable mood, very high self esteem, decreased need for sleep, pressure to keep talking, racing thoughts, being easily distracted, frequently involved in activities with a large risk for bad consequences (for example, excessive buying sprees).
- Duloxetine may interact with medications you are currently taking, or that may be added in the future. Be sure that you know all of your medications so that your doctor or pharmacist can know if any drug–drug interactions are occurring.
- You should not drink alcohol or use illegal drugs while taking duloxetine.
Are there specific concerns about Cymbalta® and pregnancy?
If you are planning on becoming pregnant, notify your healthcare provider so that he/she can best manage your medications. People living with MDD or DPN who wish to become pregnant face important decisions, each with risks and benefits as it relates to how the illness, medications and the risks to the fetus may interact. This is a complex decision as untreated MDD or DPN has risks as well to mother and fetus. There are many dimensions to these choices, so be sure to confer with your doctor and caregivers.
Since duloxetine is a newer medication, there is less information about its use in pregnant women. Duloxetine has caused abnormal effects on fetal and infant development in animals, but there are no human studies. Also, babies born to mothers who have taken SNRIs do seem to be at risk for withdrawal effects. These symptoms can include: breathing and eating difficulties, increased reflexes, increased or decreased muscle tone, irritability, constant crying, and seizures. Before your baby is born, you may wish to discuss the possibility of decreasing, and then stopping, duloxetine with your healthcare provider in order to decrease your baby’s risk of withdrawal.
For mothers who have taken SSRIs (drugs related to duloxetine) during their pregnancy, there appears to be less than a 1% chance of infants developing persistent pulmonary hypertension. This is a potentially fatal condition that is associated with use of the antidepressant in the second half of pregnancy. However, women who discontinued antidepressant therapy were five times more likely to have a depression relapse than those who continued their antidepressant. If you are pregnant, please discuss the risks and benefits of antidepressant use with your healthcare provider.
Regarding breast-feeding, caution is advised since duloxetine does pass into breast milk.
What should I discuss with my healthcare provider before taking Cymbalta®?
- Symptoms that are most bothersome to you about your condition
- If you have thoughts of suicide
- Medications you have taken in the past to treat MDD or DPN
- All other medications you are currently taking and any medication allergies you have.
- Any medication side effects that you may have experienced in the past, or are currently experiencing
- If you are pregnant, plan to become pregnant, or are breast-feeding
- If you drink alcohol or use illegal drugs
- Any medical problems you have, especially if you have liver disease, kidney disease, hypertension, diabetes, or uncontrolled narrow-angle glaucoma
How should I take Cymbalta®?
- Duloxetine is usually taken once or twice a day, and may be taken with or without food. Your healthcare provider will determine the dose that is right for you based upon your response.
- Use a pillbox or calendar to help you remember to take your medication.
- Swallow the capsule whole. Do not chew, crush, or sprinkle the contents on foods or liquids.
What happens if I miss a dose of Cymbalta®?
If you miss a dose of duloxetine, take it as soon as you remember to. But only if it is not too close to when your next dose is due. If it is close to your next dose, wait until then to take the medication and skip the missed dose. Do not double your next dose or take more than your prescribed dose. Discussing this scenario with your healthcare provider ahead of time is advised.
What should I avoid while taking Cymbalta®?
- In some patients, duloxetine may cause dizziness or drowsiness. Make sure you know how you react to this medication before you drive, operate machinery, or do other activities that may be dangerous if you are not alert.
- Avoid drinking alcohol or using illegal drugs while you are taking duloxetine because the therapeutic effects of duloxetine may be diminished.
- Avoid skipping or missing doses of this medication. Duloxetine is meant to be taken on a daily basis in order to get your symptoms under control. Once symptoms are controlled, duloxetine should still be taken on a daily basis for the best long term results in treating symptoms and preventing relapse.
What happens if I overdose with Cymbalta®?
- If an overdose occurs, whether intentional or accidental, immediate medical attention is necessary. Call your doctor or emergency medical service (911).
- Symptoms that may occur in an overdose: seizures, coma, dizziness, low blood pressure, insomnia, nausea, vomiting, rapid heart rate, drowsiness, and changes in heart rhythm. In rare instances, death has occurred.
What are the possible side effects of Cymbalta®?
Common side effects of duloxetine include: nausea, dry mouth, sweating, dizziness, diarrhea or constipation, feeling tired, insomnia, and sexual side effects. Sexual side effects may include a decreased interest in having sexual activity (libido), being unable to experience an orgasm, being unable to gain or maintain an erection (impotence), or delayed ejaculation.
Rare, but serious, side effects of duloxetine include: bleeding, decreased sodium levels in the blood (risk for seizures), “switching” from depression to mania, and seizures. As stated above, people being treated for MDD are at risk for suicidal thinking—careful attention is needed for patients who are either starting antidepressants, or who are having the dose of their antidepressant increased. Another rare, but serious side effect of SSRIs and SNRIs is the Serotonin Syndrome. When this occurs, people experience several of the following symptoms at the same time: inner restlessness, tremor (shaking), confusion, muscle spasms/jerking, muscle stiffness, increased body temperature. Serotonin syndrome in rare cases is life threatening.
Talk with your healthcare provider if you experience any side effects that are bothersome to you.
Are there any risks for taking Cymbalta® for long periods of time?
There have been no studies on the long-term risks of duloxetine since it is a newer medication. Your doctor will monitor your situation individually if he or she chooses to keep you on duloxetine for a long period of time. Similar antidepressants have been found to be safe and effective over 5-10 years of continuous treatment.
What other drugs may interact with Cymbalta®?
Duloxetine may affect the medication levels of several other medications. Examples of these medications include the following:
Tricyclic antidepressants (older)– Elavil (amitriptyline), Pamelor (nortriptyline), Tofranil (imipramine), Norpramin (desipramine), Anafranil (clomipramine)
Newer antidepressants– Prozac (fluoxetine), Paxil (paroxetine), Luvox (fluvoxamine), Effexor (Venlafaxine)
Typical (older)– Thorazine (chlorpromazine), Mellaril (thioridazine), Trilafon (perphenazine)
Other medications that may interact with duloxetine include quinolone antibiotics such as Cipro (ciprofloxacin) or Levaquin (levofloxacin), and antiarrhythmics such as Rhythmol (propafenone), quinidine and Tambocor (flecainide). Tagamet (cimetidine) may also interact with duloxetine. Tell your doctor if you are taking any of the above medications.
Duloxetine should not be taken with monoamine oxidase inhibitors (MAOIs), sumatriptan (Imitrex), or other “triptan”-type migraine medications since symptoms of serotonin syndrome have occurred. These symptoms include muscle tremor, jerking, stiffness, agitation, confusion, fever, increased pulse, and breathing rates. While this is rare, serotonin syndrome can result in death.
Duloxetine may also interact with Orap (pimozide) which can cause abnormal heart rhythms – while this is rare, these abnormal heart rhythms can result in death.
How long does it take for Cymbalta® to work?
Several weeks are often required for duloxetine to reach its maximum effectiveness; however, improvement in some symptoms may occur sooner.