Tofacitinib is a medication that belongs to a class of drugs known as Janus kinase (JAK) inhibitors. It is primarily used to treat certain autoimmune conditions by modulating the immune system.
Tofacitinib Overview
Indications:
1. Rheumatoid Arthritis (RA): Tofacitinib is approved for the treatment of moderate to severe rheumatoid arthritis in adults who have not responded adequately to or cannot tolerate methotrexate.
2. Psoriatic Arthritis (PSA): It is also used for the treatment of active psoriatic arthritis in adults.
3. Ulcerative Colitis (UC): Tofacitinib is indicated for the treatment of moderate to severe ulcerative colitis in adults who have not responded well to other therapies.
4. Ankylosing Spondylitis (AS): It is used for the treatment of active ankylosing spondylitis in adults who have had an inadequate response to conventional therapy.
Mechanism of Action
Tofacitinib works by inhibiting the Janus kinase (JAK) enzymes, which are involved in the signaling pathways of various cytokines and growth factors. By inhibiting these enzymes, tofacitinib reduces the immune system’s activity, thereby decreasing inflammation and slowing the progression of autoimmune diseases.
Dosage and Administration:
- Rheumatoid Arthritis and Psoriatic Arthritis: The usual dose is 5 mg twice daily or 11 mg once daily (extended-release).
- Ulcerative Colitis: The induction dose is typically 10 mg twice daily for at least 8 weeks, followed by a maintenance dose of 5 mg twice daily or 11 mg once daily.
- Ankylosing Spondylitis: The usual dose is 5 mg twice daily or 11 mg once daily.
Side Effects:
Common side effects include:
- Upper respiratory tract infections
- Headache
- Diarrhea
- Nasopharyngitis
- Hypertension
Serious side effects may include:
- Increased risk of infections (e.g., tuberculosis, herpes zoster)
- Blood clots
- Malignancies (e.g., lymphoma)
- Gastrointestinal perforations
Contraindications:
Tofacitinib should not be used in patients with:
- Severe liver impairment
- Active serious infections
- Hypersensitivity to tofacitinib or any of its components
Precautions:
- Infections: Patients should be monitored for signs of infection during and after treatment.
- Vaccinations: Live vaccines should be avoided while on tofacitinib.
- Pregnancy and Breastfeeding: The safety of tofacitinib during pregnancy and breastfeeding is not well established. Consult a healthcare provider for advice.
Drug Interactions:
Tofacitinib may interact with other medications, such as:
- Strong CYP3A4 inhibitors (e.g., ketoconazole)
- Immunosuppressants
- Live vaccines
Monitoring
Regular monitoring of blood counts, liver function, and lipid levels is recommended during treatment with tofacitinib.
Always consult a healthcare provider for personalized medical advice and treatment options.