Onelar (Duloxetine)

Duloxetine acts on central nervous system pathways that regulate mood and pain perception.

• Major depressive disorder: alleviates depressive symptoms and improves functional capacity.
• Generalized anxiety disorder: reduces anxiety levels and associated physical symptoms.
• Diabetic peripheral neuropathic pain: lessens pain intensity and improves quality of life.
• Fibromyalgia: decreases widespread musculoskeletal pain and fatigue.
• Chronic musculoskeletal pain: provides relief from chronic low‑back and osteoarthritis pain.

• Duloxetine inhibits the reuptake of serotonin and norepinephrine at neuronal synapses, increasing their extracellular concentrations. This dual inhibition enhances descending inhibitory pain pathways and modulates mood circuits in the central nervous system, contributing to its antidepressant and analgesic effects.

Adverse reactions to duloxetine vary in frequency and severity.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Dry mouth: reduced salivation.
• Headache: intermittent cranial pain.
• Sweating: increased perspiration.
• Fatigue: feeling of tiredness.
• Dizziness: light‑headed sensations.

Serious or Rare Side Effects

• Hepatotoxicity: signs of liver injury such as jaundice.
• Hyponatremia: low blood sodium presenting with confusion or seizures.
• Serotonin syndrome: agitation, hyperthermia, and neuromuscular abnormalities.
• Severe hypertension: markedly elevated blood pressure.
• Suicidal thoughts: emergence of suicidal ideation, especially early in treatment.
• Severe skin reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.

Before initiating duloxetine, clinicians should evaluate patient history and monitor for specific risks.

• Hepatic function: assess liver enzymes in patients with liver disease.
• Renal function: adjust monitoring in severe renal impairment.
• Cardiovascular status: watch for hypertension or tachycardia.
• Psychiatric monitoring: observe for worsening depression or emergent suicidal thoughts.
• Drug‑interaction review: avoid concomitant use with MAO inhibitors and serotonergic agents.
• Store at ambient temperature: keep below 25°C, retain in original packaging, protect from moisture and direct sunlight.

Duloxetine may interact with several medication classes, requiring careful management.

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAOIs): risk of serotonin syndrome.
• Strong CYP1A2 inhibitors (e.g., fluvoxamine): may increase duloxetine plasma levels.
• Serotonergic opioids (e.g., tramadol): heightened serotonin toxicity.

Moderate Interactions (Monitor Closely)

• CYP2D6 substrates (e.g., metoprolol): possible altered metabolism.
• NSAIDs: increased risk of gastrointestinal bleeding.
• Anticoagulants (e.g., warfarin): potential for enhanced anticoagulant effect.