Tofacitinib

Introduction:
- Oral JAK inhibitor for rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.

Drug Class:
- Janus kinase (JAK) inhibitor, targeted synthetic DMARD.

Mechanism of Action:
- Inhibits JAK1 and JAK3 (partially JAK2).
- Blocks STAT activation, reduces cytokine signaling.
- Suppresses immune response and inflammation.

Dosage:
- RA/PsA: 5 mg twice daily or 11 mg XR once daily.
- UC: Induction 10 mg twice daily for 8 weeks, then 5–10 mg BID.
- Adjust dose in renal/hepatic impairment.

Benefits:
- Reduces joint pain, swelling, stiffness.
- Improves physical function and quality of life.
- Effective in moderate to severe ulcerative colitis.
- Oral administration is convenient.

Safety Advice:
- Monitor CBC, liver function, lipids.
- Risk of serious infections (TB, herpes zoster).
- Possible malignancy and thrombosis risk.
- Avoid live vaccines.

Renal Friendly:
- Moderate/severe impairment: reduce to 5 mg once daily.
- Monitor closely.

Pregnancy Safety:
- Not recommended; fetal risk.
- Use contraception during and after therapy.

Lactation:
- Excreted in breast milk.
- Breastfeeding contraindicated.

Overdose:
- Symptoms: immunosuppression, infections, cytopenias.
- Management: supportive care, discontinue drug, monitor labs.