Duloxetine

Antidepressant Drug

Drug class: Serotonin-Norepinephrine Reuptake Inhibitor

Duloxetine (CYMBALTA)（中文：度洛西汀）

Common Strengths of Duloxetine

Duloxetine are available in the following strengths:

• 30 mg
• 60 mg

Drug Trade Names of Duloxetine

Cymbalta

Drug Usage

Duloxetine is used to treat:

• Major depressive disorder (MDD) in adults
• Generalized anxiety disorder (GAD) in adults and children 7 years and older
• Fibromyalgia in adults and children 13 years and older
• Diabetic peripheral neuropathy in adults
• Chronic musculoskeletal pain in adults

Mechanism of Action

Duloxetine is a selective serotonin and norepinephrine reuptake inibitor (SNRI). It works by increasing the levels of serotonin and norepinephrine in the brain, which helps maintain mental balance and inhibit pain signals.

Route of Administration

Oral (delayed-release capsules)

Dosages

• Depression: 40-60 mg/day, up to 120 mg/day
• Anxiety: 60 mg/day, up to 120 mg/day
• Diabetic neuropathy: 60 mg/day
• Fibromyalgia: 30-60 mg/day

Side Effects

Frequency	Adverse reactions
Common	Nausea: Stick to simple meals and avoid rich or spicy food
	Dry mouth: Chew sugar-free gum or sweets
	Constipation: Increase fiber intake and drink plenty of water
	Excessive Sweating: Wear loose clothing and use a fan if needed
	Insomnia: Take in morning
	Blurred vision
	Diarrhea (in children)
	Loss of appetite
Serious	Liver damage: Symptoms may include itching, upper right abdominal pain, dark urine, yellowing of skin/eyes
	Serotonin syndrome: Symptoms can include agitation, hallucinations, fast heart rate, dizziness, muscle tremor, nausea, vomiting
	Bleeding problems: Increased risk when taken with NSAIDs, aspirin, or anticoagulant
	Severe skin reactions: Such as Stevens-Johnson syndrome, with symptoms like skin blisters, peeling rash, mouth sores
	Vision problems: Eye pain, swelling, redness, changes in vision
	Manic: Symptoms include excessively high energy, severe trouble sleeping, racing thoughts, reckless behavior, annd unusually grand ideas
	Low sodium levels: Symptoms may include headache, confusion, weakness
	Suicidal thoughts or behaviors: Particularly in young adults and teenagers
	Urination problems: Difficulty passing urine or decreased urine flow
	Seizures

Pharmacokinetics

• Metabolism: Extensively metaboliazed in the liver
• Elimination: Primarily in urine; half-life of about 12 hours
• Onset: 1 to 4 weeks for full antidepressant effect

Drug Precautions

Pregnancy

Use with caution; potential risks to the fetus, especially in the third trimester

Breastfeeding

Use with caution; duloxetine is excreted in breast milk

Children and Elderly

• Children: Approved for generalized anxiety disorder (7+ years) and fibromyalgia (13+ years)
• Elderly: May be more sensitive to side effects; start at lower doses

Monitoring Requirements

• Blood pressure
• Blood glucose in diabetic patient
• Liver function tests
• Signs of suicidal thoughts or behaviors

Drug Interactions

Interaction Type	Examples	Notes
Major	Other serotonergic drugs include other SNRIs, SSRIs, triptans, tricyclic antidepressants, opioids, lithium, busprone, amphetamines, and St. John's Wort.	Risk of serotonin syndrome
Moderate	Antiplatelets Anticoagulants NSAID CYP2D6 substrates: dextromethorphan, metoprolol, nebivolol, tolterodine	Increased bleeding risks

FAQ

How Should I Take the Tablet?

Take the capsule whole with or without food. Do not crush, chew, or open the capsule.

What Should I Avoid While Taking?

Avoid alcohol and operating heavy machinery until you know how duloxetine affects you.

What Happens if I Miss a Dose?

Take the missed dose as soon as you remember unless it is almost time for your next dose. Do not double doses.