JAK Inhibitor - Pharmacy Freak

Mechanism of Action of Ruxolitinib

June 27, 2026 Harsh Singh Rajput

Introduction Ruxolitinib is an oral Janus kinase inhibitor used mainly in hematological and immune-mediated disorders. It is best known by the brand name Jakafi for systemic use, and it selectively inhibits Janus kinase 1 and Janus kinase 2, commonly called JAK1 and JAK2. Ruxolitinib is important in pharmacology because JAK enzymes are central mediators of … Read more

Mechanism of Action of Tofacitinib (Xeljanz)

April 10, 2026July 3, 2025 Pharmacy Freak Editorial Team Harsh Singh Rajput

Introduction Tofacitinib is an oral Janus kinase (JAK) inhibitor, primarily targeting JAK1 and JAK3. It blocks intracellular signaling of multiple inflammatory cytokines and is approved for rheumatoid arthritis (RA), psoriatic arthritis (PsA), ulcerative colitis (UC), and other immune-mediated diseases. Step-by-Step Mechanism of Action Pharmacokinetic Parameters Parameter Value Route Oral Bioavailability ~74% Time to Peak (Tmax) … Read more