托法替尼片（LuciTofa）
1. Composition:
The main ingredient of tofacitinib is tofacitinib, with the chemical name (3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)-1-piperidinecarboxylic acid. Tofacitinib is a Janus kinase (JAK) inhibitor that works by blocking specific JAK enzymes, inhibiting the signal pathways mediated by these enzymes, and reducing inflammatory responses.
2. Pharmacology:
Tofacitinib is a selective and reversible JAK inhibitor, primarily targeting JAK1 and JAK3, with some inhibitory effects on JAK2. JAKs are key enzymes in cytokine signal transduction, and the JAK-STAT pathway is involved in immune and inflammatory responses. By inhibiting this pathway, tofacitinib reduces excessive immune activation and inflammation in the body.
Tofacitinib is indicated for the following conditions:
-Rheumatoid Arthritis: Used in combination with methotrexate or as monotherapy for the treatment of moderate to severe active rheumatoid arthritis.
-Psoriatic Arthritis: For the treatment of moderate to severe active psoriatic arthritis.
-Ulcerative Colitis: For the treatment of moderate to severe active ulcerative colitis in patients who have had an inadequate response to other medications.
3. Usage Instructions:
Tofacitinib tablets are usually taken orally twice a day. For rheumatoid arthritis and psoriatic arthritis, the recommended dose is 5 mg twice daily. For ulcerative colitis, the typical initial dose is 10 mg twice daily, reduced to 5 mg twice daily after 8 weeks. The dosage should be adjusted according to the patient’s condition and the doctor's advice.
4. Development History:
Tofacitinib was developed by Pfizer and is the first oral JAK inhibitor approved by the FDA for the treatment of rheumatoid arthritis. Its development spanned several years, during which Pfizer focused on studying the role of the JAK-STAT pathway in inflammatory responses, ultimately identifying tofacitinib as an effective therapeutic agent. It was first approved by the FDA in 2012 for rheumatoid arthritis and later received approval for additional indications, including psoriatic arthritis and ulcerative colitis.
5. Mechanism of Action:
The mechanism of action of tofacitinib is the inhibition of JAK enzymes, which blocks the JAK-STAT signaling pathway. Normally, cytokines (such as interleukins and interferons) use the JAK-STAT pathway to transmit signals, activate immune cells, and trigger inflammatory responses. By inhibiting the activity of JAK1, JAK3 (and partially JAK2), tofacitinib reduces cytokine signal transmission, thereby decreasing inflammation. Its targeted action makes it an important drug for treating immune-mediated diseases.
6. Summary:
Tofacitinib tablets (LuciTofa) are the first oral JAK inhibitor used to treat inflammatory diseases such as rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. Its primary mechanism is inhibiting JAK enzyme activity, reducing excessive immune system activation and inflammation caused by the JAK-STAT pathway. Tofacitinib provides an effective treatment option for many patients who do not respond well to traditional medications.
