Duloxetine: The Pharmacological And Clinical Profile Of A Drug From The Group Of Serotonin And Noradrenaline Reuptake Inhibitors

Duloxetine, a serotonin and noradrenaline reuptake inhibitor, is registered in Poland for treatment of depressive disorders, generalized anxiety disorder and peripheral diabetic neuropathy. However, research has also confirmed its efficacy in other disorders associated with neuropathic pain, fibromyalgia, urinary incontinence and for relieving menopause symptoms. Duloxetine is an oral drug in the form of gastro-resistant capsules (30, 60, 90 and 120 mg). Its serum concentrations show high individual variability. Absolute bioavailability averages 50%, but may range from 32 to 80%. In humans, duloxetine binds with plasma proteins in 96%; it is intensively metabolised by CYP1A2 and CYP2D6. Due to the intensive metabolism by CYP1A2, substances that inhibit this enzyme (such as fluvoxamine, ciprofloxacin and enoxacin) increase duloxetine concentration significantly and may result in toxicity. In registered indications, duloxetine has at least equivalent efficacy to other drugs used in first-line therapy. It is both well-tolerated and safe, also in terms of cardiovascular effects. The most common adverse effects include: nausea, dry mouth, constipation, insomnia, dizziness, fatigue and drowsiness, excessive sweating and lower appetite. Patients treated with duloxetine develop sexual dysfunctions, similar to those associated with serotonin drugs. As with venlafaxine or paroxetine, withdrawal symptoms do develop after abrupt discontinuation of duloxetine therapy. This article presents basic pharmacological properties and the clinical profile of duloxetine.