Baricitinib
Brand names: Olumiant
Baricitinib is an oral Janus kinase (JAK) inhibitor used in rheumatoid arthritis and other immune-mediated conditions such as atopic dermatitis and alopecia areata.
Adult dose
Dose adjustments
Adults: the recommended dose is 2 mg once daily if creatinine clearance is between 30 and 60 mL/min. Paediatric patients with creatinine clearance 30-60 mL/min: halve the recommended dose. Baricitinib is not recommended for use in patients with creatinine clearance < 30 mL/min.
Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.
Contraindications
- Hypersensitivity to the active substance or to any of the excipients
- Pregnancy
Side effects
- Increased LDL cholesterol (26.0%) and hypercholesterolaemia (very common); hypertriglyceridaemia (common)
- Upper respiratory tract infections (16.9%, very common); herpes simplex (3.2%), herpes zoster, urinary tract infections (2.9%), gastroenteritis and pneumonia (common); serious pneumonia and serious herpes zoster occurred uncommonly in rheumatoid arthritis
- Headache (5.2%, common); nausea and abdominal pain (common); diverticulitis (uncommon)
- Deep vein thrombosis (common in RA trials) and pulmonary embolism (uncommon)
- ALT and AST increased >= 3 x ULN (common); thrombocytosis > 600 x 10^9 cells/L (common), neutropenia < 1 x 10^9 cells/L (uncommon); rash (common), acne, creatine phosphokinase increased > 5 x ULN, weight increased
Interactions
- Strong Organic Anion Transporter 3 (OAT3) inhibitors such as probenecid — reduce the dose: 2 mg once daily in adults, and halve the recommended dose in paediatric patients (§4.2, cross-refers to §4.5)
- Methotrexate — in rheumatoid arthritis clinical studies, combination with methotrexate resulted in an increased frequency of infections compared with baricitinib monotherapy (§4.4)
- This interaction list may be incomplete — check the full SPC.
Clinical monograph
How it works
It inhibits JAK1 and JAK2, interrupting cytokine signalling pathways that drive inflammation in immune-mediated disease.
Prescribing in practice
- The MHRA advises that JAK inhibitors carry risks of serious infection, venous thromboembolism, major cardiovascular events and malignancy, with cautious use particularly in older patients and those with risk factors.
- Screen for and treat latent tuberculosis and chronic viral hepatitis before starting, and ensure vaccinations are up to date.
- Avoid live vaccines during treatment.
Monitoring
Monitor full blood count, lipids, liver function and for signs of infection before and during treatment as set out in current prescribing references.
Counselling the patient
- Report any signs of infection, chest pain, breathlessness or leg swelling promptly.
- Avoid live vaccines and tell other clinicians you are taking an immunosuppressant.
Evidence & guidelines
MHRA safety reviews of JAK inhibitors inform their restricted use in patients with cardiovascular and malignancy risk factors.
Reference: NICE TA466; RA-BEAM trial; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.
- SMART2 Risk Score for Recurrent Vascular Events · Cardiovascular Risk
- PCSK9 Inhibitor Eligibility (NICE TA393 / TA394) · Lipid Management
- Immune-Related Adverse Events (irAE) -- GI Toxicity Colitis Grading · Oncology-Related GI
- irAE Hepatitis Grading (CTCAE) · Immunotherapy
- DIPSS — Dynamic International Prognostic Scoring System for Myelofibrosis · Cancer Prognosis
- BALL Score for Relapsed/Refractory CLL · Leukaemia
- Cutaneous Lupus Erythematosus · BAD; EULAR
- Osteoporosis / Fragility Fracture · NOGG 2021; NICE NG147; NG224
- Arteritic AION (Giant Cell Arteritis) · RCOphth; BSR
- Osteoarthritis Hip / Knee Management · NICE NG226 (2022)
- Lupus Nephritis · EULAR/ERA-EDTA 2019; KDIGO 2024
- Rheumatoid Arthritis Management · NICE CG79 2018 / EULAR 2022