Duloxetine is a medication in the class of anti-depressant drugs, used to treat major depression and provide relief from nerve pain or peripheral neuropathy in diabetics. It belongs to a class of medicines called the selective serotonin and norepinephrine reuptake inhibitors (SSNRIs).

Originally produced by Lilly researchers, Duloxetine hydrochloride was patented in 1981 and was approved for use by the Food and Drug Administration (FDA) in 2004. The drug is sold under the drug name Cymbalta and is officially prescribed for the following purposes:

Major Depressive Disorder Diabetic Peripheral Neuropathic Pain

Cymbalta is also commonly prescribed for:

Panic/Anxiety Bipolar depression Fibromyalgia Stress urinary incontinence in women Irritable Bowel Syndrome

Duloxetine is also sold under the brand names Duloxetine HCI, Duloxetine Hydrochloride and Yentreve.

Research and Analysis

A report published in the journal, Diabetes Care, January 2007, indicates that duloxetine might raise the blood glucose levels, both over a short as well as long time periods. Cholesterol levels were also found to be slightly affected by duloxetine, while weight loss was experienced by some patients in short-term use.

Working Principle

Duloxetine primarily works by restoring the balance of two kinds of natural substances, including neurotransmitters known as serotonin and norepinephrine in the brain.

When serotonin and norepinephrine are released from nerve cells in the brain, they act to lighten the mood of the patient. When reabsorbed into the nerve cells, they no longer have an effect on the mood. Duloxetine works by preventing serotonin, norepinphrine and dopamine from being reabsorbed into the nerve cells in the brain. This helps to prolong the ‘mood lightening’ effect of the released serotonin and norepinephrine. Thus, duloxetine is also thought to relieve depression.

Dosage and Administration

Each capsule of duloxetine contains enteric-coated pellets of 22.4, 33.7 or 67.3 mg of duloxetine hydrochloride, which is further equivalent to 20, 30 or 60 mg of duloxetine, respectively.

These enteric-coated pellets are designed to prevent degradation of the drug in the acidic environment of the stomach. At the initiation of therapy, the recommended oral dose is 40 mg/day to 60 mg/day. Meanwhile, the recommended dose for diabetic peripheral neuropathic pain is 60 mg taken once daily.

Duloxetine is generally taken orally, by mouth, with or without food. It is important that this medicine is not crushed, chewed or mixed with food or liquid. Experts suggest that for best results, duloxetine should be taken at the same time everyday and should be continued even if the patient feels well.

It takes a time period of 1 to 4 weeks before the full benefit of the drug takes effect. To discontinue, it important to take prior permission from your doctor.

Side Effects

As with all forms of medication, duloxetine also carries of the risk of a series of side effects. These can range form being common to rare and serious.

Here we briefly list each of the side effects associated with the use of duloxetine.

a) Common

These side effects are quite common and do not require medical attention, unless they persist for long or become too severe. These include:

Nausea Dry mouth Constipation Loss of appetite Fatigue Drowsiness Dizziness Excessive sweating Blurred vision Rash Itching

b) Rare

Though these side effects are quite rare and generally do not occur, yet immediate medical help should be sought if any of these is experienced.

Severe and unusual mood swings (such as anxiety, mania) Uncontrolled movements (tremors) Difficulty in urination Chest pain Stomach pain Black stools Vomit Easy bruising/bleeding Seizures Weight loss Change in sexual desire/ability

In addition, some media reports have also revealed instances of completed suicide attempts and hepatic disorders, associated with the use of duloxetine. Experts strongly recommend that all adults and pediatric patients on a prescription of duloxetine should be closely monitored for clinical worsening, suicidality and unusual changes in behavior, especially when the dosage is decreased.


The use of duloxetine is contraindicated in individuals with the following cases:

  • Hypersensitivity to duloxetine or any of the active ingredients
  • Patients taking monoamine oxidase inhibitors
  • Patients with uncontrolled narrow-angle glaucoma
  • Patients with kidney disease
  • Patients on prescription of MAO inhibitors and thioridazine
  • Pregnant or lactating mothers