Duloxetine hydrochloride is a white to slightly brownish white solid, which is slightly soluble in water. Each capsule contains enteric-coated pellets of 22.4, 33.7, or 67.3 mg of duloxetine hydrochloride equivalent to 20, 30, or 60 mg of duloxetine, respectively. Taking duloxetine in higher doses or more often than prescribed will not make it more effective, and may increase side effects. Swallow the capsule whole and do not crush, chew, break, or open it. You may take duloxetine with or without food. Duloxetine, tricyclic antidepressants and anticonvulsants have similar tolerability while the opioids caused more side effects. Another review in Prescrire International considered the moderate pain relief achieved with duloxetine to be clinically insignificant and the results of the clinical trials unconvincing. Side Effects. See also Warning section. Nausea, dry mouth, constipation, loss of appetite, tiredness, drowsiness, or increased sweating may occur. If you experience drowsiness, dizziness, hypotension or a headache as side-effects when using Duloxetine Hydrochloride medicine then it may not be safe to drive a vehicle or operate heavy machinery. Learn about warnings, side effects, dosage, and more for duloxetine oral capsule. Duloxetine oral capsule is a prescription medication used to treat depression, anxiety, diabetes nerve pain. What are some other side effects of Duloxetine? All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away: Upset stomach or throwing up. The most common side effects of duloxetine are nausea, dry mouth, constipation, diarrhea, fatigue, difficulty sleeping, and dizziness. Increased blood pressure can occur and should be monitored. Duloxetine can pass into breast milk, but effects on the nursing baby are not known. Tell your doctor if you are breast-feeding. Tell your doctor if you are breast-feeding. Duloxetine is not approved for use by anyone younger than 18 years old. Cymbalta (duloxetine) is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) used for treating depression, anxiety disorder, and pain associated with diabetic peripheral neuropathy or fibromyalgia.