Onelar (Duloxetine)

Duloxetine acts on serotonergic and noradrenergic pathways to improve mood, anxiety and pain perception.

• Major depressive disorder: alleviates depressive symptoms and improves overall mood.
• Generalized anxiety disorder: reduces excessive worry and anxiety-related physical symptoms.
• Diabetic peripheral neuropathic pain: relieves chronic neuropathic pain associated with diabetes.
• Fibromyalgia: decreases widespread musculoskeletal pain and improves functional status.
• Chronic musculoskeletal pain: mitigates persistent pain and enhances physical activity.

• Duloxetine inhibits the reuptake of serotonin and norepinephrine at presynaptic neuronal terminals, leading to increased concentrations of these neurotransmitters in the synaptic cleft. The enhanced serotonergic and noradrenergic signaling modulates mood, anxiety and pain pathways, contributing to its therapeutic effects in depression, anxiety disorders and chronic pain conditions.

Common side effects are generally mild to moderate and may resolve with continued therapy.

Common Side Effects

• Nausea: transient gastrointestinal discomfort.
• Dry mouth: reduced salivary flow.
• Dizziness: light‑headed sensation, especially on standing.
• Headache: mild to moderate intensity.
• Increased sweating: excessive perspiration.
• Somnolence: feeling of tiredness or sleepiness.

Serious or Rare Side Effects

• Hepatotoxicity: elevated liver enzymes or liver injury.
• Serotonin syndrome: agitation, hyperthermia, muscle rigidity.
• Suicidal thoughts: emergence of suicidal ideation, particularly in young adults.
• Severe hypertension: marked increase in blood pressure.
• Stevens‑Johnson syndrome: severe skin reactions with blistering.

Before initiating duloxetine, clinicians should evaluate several safety aspects.

• Assess hepatic function: monitor liver enzymes prior to and during treatment.
• Evaluate renal function: adjust dosing in severe renal impairment.
• Screen for suicidal ideation: especially in patients under 25 years of age.
• Avoid abrupt discontinuation: taper gradually to prevent discontinuation syndrome.
• Monitor blood pressure: duloxetine may raise systolic and diastolic values.
• Store at ambient temperature: keep in the original pack, protect from moisture and light.

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

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAOIs): risk of serotonin syndrome.
• Linezolid or methylene blue: potent serotonergic activity.
• Serotonergic opioids (e.g., tramadol, fentanyl): increased serotonin toxicity.
• CYP1A2 inhibitors (e.g., fluvoxamine): may raise duloxetine plasma levels.
• Other SSRIs or SNRIs: combined use can precipitate serotonin syndrome.

Moderate Interactions (Monitor Closely)

• CYP2D6 inhibitors (e.g., quinidine): may increase duloxetine exposure.
• CYP2D6 inducers (e.g., rifampin): may reduce therapeutic effect.
• Anticoagulants (e.g., warfarin): potential for enhanced bleeding.
• NSAIDs: additive risk of gastrointestinal bleeding.
• Alcohol: may potentiate central nervous system depression.