Duloxetine

Duloxetine comes as a delayed-release (releases the medication in the intestine to prevent break-down of the medication by stomach acids) capsule to take by mouth. When duloxetine is used to treat depression, it is usually taken once or twice a day with or without food. When duloxetine is used to treat generalized anxiety disorder, the pain of diabetic neuropathy, fibromyalgia, or ongoing bone or muscle pain, it is usually taken once a day with or without food. Take duloxetine at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take duloxetine exactly as directed. Do not take more or less of it, take it more often, or take it for a longer time than prescribed by your doctor.

Swallow the delayed-release capsules whole; do not split, chew, or crush them. Do not open the delayed-release capsules and mix the contents with liquids or sprinkle the contents on food.

Your doctor may start you on a low dose of medication and increase your dose after one week.

Duloxetine may help control your symptoms but will not cure your condition. It may take 1 to 4 weeks or longer before you feel the full benefit of duloxetine. Continue to take duloxetine even if you feel well. Do not stop taking duloxetine without talking to your doctor. Your doctor will probably decrease your dose gradually. If you suddenly stop taking duloxetine, you may experience withdrawal symptoms such as nausea; vomiting; diarrhea; anxiety; dizziness; tiredness; headache; pain, burning, numbness, or tingling in the hands or feet; irritability; difficulty falling asleep or staying asleep; sweating; and nightmares. Tell your doctor if you experience any of these symptoms when your dose of duloxetine is decreased.

Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) antidepressants used for treating depression, anxiety disorder, and pain. Other drugs in this class include milnacipran (Savella), venlafaxine (Effexor), and desvenlafaxine (Pristiq). Duloxetine affects neurotransmitters, the chemicals that nerves within the brain make and release in order to communicate with one another. Neurotransmitters either travel across the space between nerves and attach to receptors on the surface of nearby nerves or they attach to receptors on the surface of the nerves that produced them, to be taken up by the nerve and released again (a process referred to as re-uptake).

Many experts believe that an imbalance among neurotransmitters is the cause of depression as well as other psychiatric disorders. Serotonin and norepinephrine are two neurotransmitters released by nerves in the brain. Duloxetine works by preventing the reuptake of serotonin and epinephrine by nerves after they have been released. Since uptake is an important mechanism for removing released neurotransmitters and terminating their actions on adjacent nerves, the reduced uptake caused by duloxetine increases the effect of serotonin and norepinephrine in the brain. The mechanism responsible for its effectiveness treating pain is not known but also is thought to involve its effects on serotonin and norepinephrine in the brain. Duloxetine was approved by the FDA in August 2004.

Duloxetine is approved for treating the following conditions:

• Major depressive disorder (MDD)
• Generalized anxiety disorder (GAD)
• Diabetic peripheral neuropathic pain
• Fibromyalgia
• Chronic musculoskeletal pain

Duloxetine may be found in some form under the following brand names:

• Cymbalta

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of duloxetine there are no specific foods that you must exclude from your diet when receiving duloxetine.

WARNING: SUICIDALITY AND ANTIDEPRESSANT DRUGS

Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders. Anyone considering the use of duloxetine or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. Duloxetine is not approved for use in pediatric patients.

Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor antidepressant (SSNRI). Duloxetine affects chemicals in the brain that may be unbalanced in people with depression.

Duloxetine is used to treat major depressive disorder in adults. Duloxetine is also used to treat general anxiety disorder in adults and children who are at least 7 years old.

Duloxetine is also used in adults to treat fibromyalgia (a chronic pain disorder), or chronic muscle or joint pain (such as low back pain and osteoarthritis pain).

Duloxetine is also used to treat pain caused by nerve damage in adults with diabetes (diabetic neuropathy).

Duloxetine may also be used for purposes not listed in this medication guide.

You should not use duloxetine if you are allergic to it.

Do not take duloxetine within 5 days before or 14 days after you have used an MAO inhibitor, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine. A dangerous drug interaction could occur.

Some medicines can interact with duloxetine and cause a serious condition called serotonin syndrome. Be sure your doctor knows if you also take stimulant medicine, opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson's disease, migraine headaches, serious infections, or prevention of nausea and vomiting. Ask your doctor before making any changes in how or when you take your medications.

To make sure duloxetine is safe for you, tell your doctor if you have ever had:

• liver or kidney disease;

• seizures or epilepsy;

• a bleeding or blood clotting disorder;

• high blood pressure;

• narrow-angle glaucoma;

• bipolar disorder (manic depression); or

• drug addiction or suicidal thoughts.

Some young people have thoughts about suicide when first taking an antidepressant. Your doctor will need to check your progress at regular visits while you are using duloxetine. Your family or other caregivers should also be alert to changes in your mood or symptoms.

It is not known whether duloxetine will harm an unborn baby. However, duloxetine may cause problems in a newborn if you take the medicine during the third trimester of pregnancy. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

If you are pregnant, your name may be listed on a pregnancy registry. This is to track the outcome of the pregnancy and to evaluate any effects of duloxetine on the baby.

Duloxetine can pass into breast milk, but effects on the nursing baby are not known. Tell your doctor if you are breast-feeding.

Duloxetine is not approved for use by anyone younger than 18 years old.

In the U.S.

• Cymbalta
• Irenka

Available Dosage Forms:

• Capsule
• Capsule, Delayed Release

Therapeutic Class: Antidepressant

Pharmacologic Class: Serotonin/Norepinephrine Reuptake Inhibitor

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

(doo LOX e teen)

AUC was ~25% higher in elderly women.

Cigarette smoking: Duloxetine bioavailability is reduced by approximately 33% in smokers.

Use of monoamine oxidase (MAO) inhibitors intended to treat psychiatric disorders (concurrently or within 14 days of discontinuing the MAO inhibitor); initiation of MAO inhibitor intended to treat psychiatric disorders within 5 days of discontinuing duloxetine; initiation of duloxetine in a patient receiving linezolid or intravenous methylene blue.

Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to duloxetine or any component of the formulation; hepatic impairment; severe renal impairment (eg, CrCl <30 mL/minute) or end-stage renal disease (ESRD); uncontrolled narrow-angle glaucoma; concomitant use with thioridazine or with potent CYP1A2 inhibitors.

Store at 25°C (77°F); excursions are permitted between 15°C and 30°C (59°F and 86°F).

Major psychiatric warnings:

• Suicidal thinking/behavior: [US Boxed Warning]: Antidepressants increase the risk of suicidal thinking and behavior in children, adolescents, and young adults (18 to 24 years of age) with major depressive disorder (MDD) and other psychiatric disorders; consider risk prior to prescribing. Short-term studies did not show an increased risk in patients >24 years of age and showed a decreased risk in patients ≥65 years. Closely monitor for clinical worsening, suicidality, or unusual changes in behavior, particularly during the initial 1 to 2 months of therapy or during periods of dosage adjustments (increases or decreases); the patient’s family or caregiver should be instructed to closely observe the patient and communicate condition with healthcare provider. A medication guide concerning the use of antidepressants in children and teenagers should be dispensed with each prescription.

• The possibility of a suicide attempt is inherent in major depression and may persist until remission occurs. Worsening depression and severe abrupt suicidality that are not part of the presenting symptoms may require discontinuation or modification of drug therapy. Use caution in high-risk patients during initiation of therapy.

• Prescriptions should be written for the smallest quantity consistent with good patient care. The patient's family or caregiver should be alerted to monitor patients for the emergence of suicidality and associated behaviors such as anxiety, agitation, panic attacks, insomnia, irritability, hostility, impulsivity, akathisia, hypomania, and mania; patients should be instructed to notify their healthcare provider if any of these symptoms or worsening depression or psychosis occur.

Concerns related to adverse effects:

• Bleeding risk: May impair platelet aggregation resulting in increased risk of bleeding events, particularly if used concomitantly with aspirin or NSAIDs due to ulcerogenic potential. Bleeding related to SNRI use has been reported to range from relatively minor bruising and epistaxis to life-threatening hemorrhage.

• CNS depression: Has a low potential to impair cognitive or motor performance; caution operating hazardous machinery or driving.

• Dermatologic: Severe skin reactions (including Stevens-Johnson syndrome and erythema multiforme) have been reported; discontinue immediately if blisters, peeling rash, mucosal erosions, or any other signs of hypersensitivity reactions are suspected.

• Fractures: Bone fractures have been associated with antidepressant treatment. Consider the possibility of a fragility fracture if an antidepressant-treated patient presents with unexplained bone pain, point tenderness, swelling, or bruising (Rabenda, 2013; Rizzoli, 2012).

• Hepatotoxicity: Avoid use in patients with substantial ethanol intake, evidence of liver disease or hepatic impairment. Rare cases of hepatic failure (including fatalities) have been reported with use. Hepatitis with abdominal pain, hepatomegaly, elevated transaminase levels >20 times the upper limit of normal (ULN) with and without jaundice have all been observed. Discontinue therapy with the presentation of jaundice or other signs of hepatic dysfunction and do not reinitiate therapy unless another source or cause is identified.

• Hyperglycemia: Modest increases in serum glucose and hemoglobin A1c (HbA1c) levels have been observed in some diabetic patients receiving duloxetine for diabetic peripheral neuropathic pain (DPNP).

• Ocular effects: May cause mild pupillary dilation which in susceptible individuals can lead to an episode of narrow-angle glaucoma. Consider evaluating patients who have not had an iridectomy for narrow-angle glaucoma risk factors.

• Orthostatic hypotension/syncope: May cause orthostatic hypotension/syncope, especially within the first week of therapy and after dose increases. Carefully monitor blood pressure with initiation of therapy, dose increases (especially in patients receiving >60 mg/day), or when using concomitant vasodilators or CYP1A2 inhibitors. Consider dose reduction or discontinuation of duloxetine if orthostatic hypotension or syncope occurs.

• Serotonin syndrome (SS) reactions: Potentially life-threatening serotonin syndrome (SS) has occurred with serotonergic agents (eg, SSRIs, SNRIs), particularly when used in combination with other serotonergic agents (eg, triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, and St John's wort) or drugs that impair serotonin metabolism (eg, MAO inhibitors, specifically linezolid, methylene blue, and others used for psychiatric disorders). Monitor patients closely for signs/symptoms of SS which may include mental status changes (eg, agitation, hallucinations, delirium), seizures, autonomic instability (eg, tachycardia, dizziness, diaphoresis), neuromuscular symptoms (eg, tremor, rigidity, myoclonus), or gastrointestinal symptoms (eg, nausea, vomiting, diarrhea). Discontinue treatment (and any concomitant serotonergic agents) immediately if signs/symptoms arise.

• Sexual dysfunction: May cause or exacerbate sexual dysfunction.

• SIADH and hyponatremia: SSRIs and SNRIs have been associated with the development of SIADH; hyponatremia has been reported rarely (including severe cases with serum sodium <110 mmol/L), predominately in the elderly. Volume depletion and/or concurrent use of diuretics likely increases risk.

• Urinary hesitancy: May cause increased urinary resistance; advise patient to report symptoms of urinary hesitation/difficulty.

Disease-related concerns:

• Gastroparesis: Use caution in patients with impaired gastric motility (eg, some diabetics); may affect stability of the capsule's enteric coating.

• Hepatic impairment: Avoid use in patients with chronic liver disease or cirrhosis.

• Hypertension: Use caution in patients with hypertension. Although no statistically significant differences in the frequency of sustained elevations of blood pressure were observed in clinical trials when compared with placebo, modest increases in blood pressure have been reported with use. Additionally, rare cases of hypertensive crisis have been reported; blood pressure should be evaluated prior to initiating therapy and periodically thereafter; consider dose reduction or gradual discontinuation of therapy in individuals with sustained hypertension during therapy.

• Mania/hypomania: May worsen psychosis in some patients or precipitate a shift to mania or hypomania in patients with bipolar disorder. Monotherapy in patients with bipolar disorder should be avoided. Patients presenting with depressive symptoms should be screened for bipolar disorder. Duloxetine is not FDA approved for the treatment of bipolar depression.

• Renal impairment: Use with caution; clearance is decreased and plasma concentrations are increased; avoid use in patients with CrCl <30 mL/minute or ESRD.

• Seizure disorders: Use caution in patients with a previous seizure disorder or condition predisposing to seizures such as brain damage or alcoholism (Montgomery 2005).

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Fall risk: Falls with serious consequences including bone fractures and hospitalization have been reported in patients receiving therapeutic doses of duloxetine. The risk of falling appears related to the degree of orthostatic decrease in blood pressure. Risks may also be greater in elderly patients, patients taking concomitant medications that induce orthostatic hypotension or are potent CYP1A2 inhibitors, and in patients taking doses >60 mg/day. Consider dose reduction or discontinuation of duloxetine if falls occur.

• Sucrose intolerance: Some formulations may contain sucrose; patients with fructose intolerance, glucose-galactose malabsorption, or sucrase-isomaltase deficiency should avoid use.

Other warnings/precautions:

• Discontinuation syndrome: Abrupt discontinuation or interruption of antidepressant therapy has been associated with a discontinuation syndrome. Symptoms arising may vary with antidepressant however commonly include nausea, vomiting, diarrhea, headaches, lightheadedness, dizziness, diminished appetite, sweating, chills, tremors, paresthesias, fatigue, somnolence, and sleep disturbances (eg, vivid dreams, insomnia). Less common symptoms include electric shock-like sensations, cardiac arrhythmias (more common with tricyclic antidepressants), myalgias, parkinsonism, arthralgias, and balance difficulties. Psychological symptoms may also emerge such as agitation, anxiety, akathisia, panic attacks, irritability, aggressiveness, worsening of mood, dysphoria, mood lability, hyperactivity, mania/hypomania, depersonalization, decreased concentration, slowed thinking, confusion, and memory or concentration difficulties. Greater risks for developing a discontinuation syndrome have been associated with antidepressants with shorter half-lives, longer durations of treatment, and abrupt discontinuation. For antidepressants of short or intermediate half-lives, symptoms may emerge within 2 to 5 days after treatment discontinuation and last 7 to 14 days (APA 2010; Fava 2006; Haddad 2001; Shelton 2001; Warner 2006).

Blood pressure should be checked prior to initiating therapy and then regularly monitored, especially in patients with a high baseline blood pressure; mental status for depression, suicidal ideation (especially at the beginning of therapy or when doses are increased or decreased), anxiety, social functioning, mania, panic attacks or other unusual changes in behavior; glucose levels and HbA1c levels in diabetic patients, creatinine, BUN, transaminases

Adverse events have been observed in animal reproduction studies. Nonteratogenic effects in the newborn following SSRI/SNRI exposure late in the third trimester include respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hyper- or hypotonia, hyper-reflexia, jitteriness, irritability, constant crying, and tremor. Symptoms may be due to the toxicity of the SNRIs/SSRIs or a discontinuation syndrome and may be consistent with serotonin syndrome associated with SSRI treatment. The long-term effects of in utero SNRI/SSRI exposure on infant development and behavior are not known.

The ACOG recommends that therapy with SSRIs or SNRIs during pregnancy be individualized; treatment of depression during pregnancy should incorporate the clinical expertise of the mental health clinician, obstetrician, primary health care provider, and pediatrician. According to the American Psychiatric Association (APA), the risks of medication treatment should be weighed against other treatment options and untreated depression. For women who discontinue antidepressant medications during pregnancy and who may be at high risk for postpartum depression, the medications can be restarted following delivery. Treatment algorithms have been developed by the ACOG and the APA for the management of depression in women prior to conception and during pregnancy.

Health care providers are encouraged to enroll women exposed to duloxetine during pregnancy in the Cymbalta Pregnancy Registry (866-814-6975 or http://cymbaltapregnancyregistry.com).

Pregnant women exposed to antidepressants during pregnancy are encouraged to enroll in the National Pregnancy Registry for Antidepressants (NPRAD). Women 18 to 45 years of age or their health care providers may contact the registry by calling 844-405-6185. Enrollment should be done as early in pregnancy as possible.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.