Generic Name

Baricitinib

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Classification

FDA Approved Indications

• Rheumatoid arthritis in adults who have not responded well to other treatments
• COVID-19 (emergency use authorization for certain hospitalized patients, as of 2021)

Mechanism of Action

Baricitinib inhibits Janus kinase (JAK) 1 and 2 enzymes, disrupting the JAK-STAT signaling pathway, which is involved in the inflammatory process and immune response, thereby reducing inflammation.

Dosage and Administration

Adult: Typically, 2 mg or 4 mg once daily, with adjustments based on response and tolerability.

Pediatric: Not approved for pediatric use.

Geriatric: Use with caution; assess renal function regularly.

Renal Impairment: Dose adjustment may be necessary in patients with renal impairment.

Hepatic Impairment: No specific adjustment required for mild to moderate hepatic impairment; caution in severe hepatic impairment.

Pharmacokinetics

Absorption: Well absorbed orally, peak plasma levels in approximately 1 hour.

Distribution: Wide distribution with a volume of distribution approximately 76 L.

Metabolism: Primarily metabolized via CYP3A4 and other pathways; minimal formation of active metabolites.

Excretion: Excreted mainly via urine (about 75%), with some in feces.

Half Life: Approximately 12 hours.

Contraindications

• Hypersensitivity to baricitinib or any component of the formulation.
• Active infections, including tuberculosis.

Precautions

• Risk of serious infections, including opportunistic infections; screen for infections before initiating treatment.
• Monitor patients for signs of infection.
• Use caution in patients with a history of cardiac or pulmonary conditions, or liver disease.
• Assess risk of thrombosis; caution in patients with a history of thromboembolic events.

Adverse Reactions - Common

• Infections (upper respiratory, urinary tract infections) (Common)
• Elevated liver enzymes (Common)
• Increased blood lipids (LDL, HDL) (Common)
• Nausea, headache (Common)

Adverse Reactions - Serious

• Serious infections (pneumonia, cellulitis, herpes zoster) (Uncommon)
• Thromboembolic events (deep vein thrombosis, pulmonary embolism) (Uncommon)
• Blood disorders (neutropenia, anemia) (Uncommon)
• Liver damage (Uncommon)

Drug-Drug Interactions

• Other immunosuppressants or biologic agents
• CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) which may increase baricitinib levels
• CYP3A4 inducers (e.g., rifampin) which may decrease effectiveness

Drug-Food Interactions

• No significant interactions reported

Drug-Herb Interactions

• Limited data, caution advised

Nursing Implications

Patient/Family Teaching

• Report signs of infection, unusual bleeding, or blood clots immediately.
• Take the medication exactly as prescribed.
• Maintain regular follow-up appointments and lab assessments.
• Avoid live vaccines during treatment.

Special Considerations

Black Box Warnings:

• Serious infections, including tuberculosis and opportunistic infections.
• Malignancies, including lymphomas and other cancers.
• Thromboembolism, including deep vein thrombosis and pulmonary embolism.

Genetic Factors: Pharmacogenetic testing not routinely required.

Lab Test Interference: May elevate liver enzymes and lipid levels; monitor accordingly.

Overdose Management

Signs/Symptoms: Potential increased risk of infections, liver enzyme elevations, and blood count abnormalities.

Treatment: Supportive care; no specific antidote. Discontinue drug and provide symptomatic treatment as needed.

Storage and Handling

Storage: Store at room temperature, 20°C to 25°C (68°F to 77°F).

Stability: Stable for the duration of the shelf-life when stored properly.