What is the use of Duloxetine (Cymbalta)?

From the Guidelines

Duloxetine is recommended as a first-line treatment for certain types of chronic pain, including neuropathic pain, fibromyalgia, and osteoarthritis, due to its efficacy in reducing pain intensity and improving function, as shown in recent studies 1.

Key Points

• The typical starting dose of duloxetine is 30 mg once daily, usually increased to 60 mg daily after one week, with a maximum dose of 120 mg daily depending on the condition being treated.
• Duloxetine should be taken at the same time each day, with or without food, and the capsule should be swallowed whole without crushing or chewing.
• Common side effects include nausea, dry mouth, constipation, decreased appetite, fatigue, sleepiness, and increased sweating.
• The medication works by increasing the levels of serotonin and norepinephrine in the brain, which helps regulate mood, reduce anxiety, and decrease pain signals.
• Patients should not stop taking duloxetine abruptly as this can cause withdrawal symptoms; dosage should be gradually reduced under medical supervision.
• It's essential to inform your doctor about all other medications you're taking, as duloxetine can interact with MAOIs, certain antibiotics, and blood thinners, among others.

Considerations

• Duloxetine has shown consistent efficacy in painful diabetic neuropathy, with effectiveness sustained for 1 year in an open-label trial 1.
• The medication has also shown efficacy in the treatment of major depression and generalized anxiety disorder, and its dosing is simple, with 60 mg once daily appearing to be as effective as 60 mg twice daily 1.
• However, duloxetine has not been studied in other types of neuropathic pain, and its efficacy in such conditions is unknown 1.
• Recent guidelines recommend duloxetine as a treatment option for osteoarthritis pain, particularly in patients with multiple joints or incompletely controlled pain with topical NSAIDs 1.
• The medication is also recommended for the treatment of fibromyalgia, with evidence showing small to moderate improvements in pain, function, and quality of life 1.

From the FDA Drug Label

Duloxetine delayed-release capsules are indicated for the treatment of: Major depressive disorder in adults Generalized anxiety disorder in adults and pediatric patients 7 years of age and older Diabetic peripheral neuropathic pain in adults Fibromyalgia in adults Chronic musculoskeletal pain in adults

The main uses of duloxetine are for the treatment of:

• Major depressive disorder in adults
• Generalized anxiety disorder in adults and pediatric patients 7 years of age and older
• Diabetic peripheral neuropathic pain in adults
• Fibromyalgia in adults
• Chronic musculoskeletal pain in adults 2

From the Research

Duloxetine Overview

• Duloxetine is a selective dual neuronal serotonin (5-Hydroxytryptamine, 5-HT) and norepinephrine reuptake inhibitor (SSNRI) 3.
• It is indicated in the United States for treatment of major depressive disorder (MDD), generalized anxiety disorder (GAD), and several chronic pain conditions, including management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic osteoarthritis (OA) pain and chronic low back pain (LBP) 3, 4.

Efficacy and Safety

• Studies have shown that duloxetine 60 mg once-daily dosing is an effective option for the management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic OA pain and chronic LBP 3.
• A systematic review of 85 studies confirmed the efficacy, safety, and tolerability of duloxetine in the treatment of MDD, GAD, neuropathic pain, fibromyalgia, and stress incontinence urinary 4.
• Duloxetine has also been found to be effective in the treatment of mood spectrum disorders, panic disorder, and certain symptom clusters of borderline personality disorder 5.

Dosage and Administration

• The approved dose range for duloxetine is 40-60 mg/day, with the most commonly used dose being 60 mg once daily 6.
• Studies have shown that rapid dose escalation of duloxetine from 60 mg/day to 120 mg/day is safe and tolerable, with most adverse events being mild and transient 7.
• The incidence of certain treatment-emergent adverse events, such as nausea, is likely to be lower at the 40 mg dose compared to the 60 mg dose 6.

Adverse Events

• Common adverse events associated with duloxetine include nausea, headache, dry mouth, dizziness, and insomnia 7, 6.
• The rate of discontinuation due to adverse events is generally low, ranging from 11.9% to 15.6% in clinical trials 7, 6.