Olumiant (baricitinib) is a targeted treatment for rheumatoid arthritis (RA) and alopecia areata (AA, a condition causing patchy hair loss). It belongs to a class of medicines called JAK inhibitors (Janus kinase inhibitors).

It works by blocking JAK enzymes (specifically JAK1 and JAK2) inside cells. These enzymes transmit signals from cytokines (inflammation-driving proteins) into cells. By blocking these signals, baricitinib reduces the inflammation causing joint damage in RA and the immune attack on hair follicles in alopecia areata.

Take one tablet once daily, with or without food. Take at the same time each day.

For rheumatoid arthritis: the usual dose is 4 mg daily. For some people (including those over 75 or with certain kidney problems), 2 mg daily may be prescribed.

Do not stop without speaking to your specialist, as symptoms can return.

Take the missed dose as soon as you remember on the same day. If you don't remember until the next day, skip the missed dose and take your usual dose that day. Never take two doses in one day.

Contact your doctor or emergency department immediately.

• Store below 30°C
• Keep in the original packaging
• Keep out of reach of children

Side effects are common and some can be serious.

Common side effects:

• Upper respiratory tract infections (such as colds and sinusitis)
• Nausea
• Raised LDL cholesterol: lipid tests should be checked regularly
• Herpes simplex and herpes zoster (cold sores and shingles): JAK inhibitors increase the risk of reactivation of herpes viruses
  

Serious side effects:

• Serious infections including TB, opportunistic infections, and sepsis
• Venous thromboembolism (blood clots, including DVT and pulmonary embolism): risk is increased with baricitinib. Report any leg pain, swelling, or sudden breathlessness
• Major cardiovascular events (heart attack, stroke): risk may be elevated, particularly in older patients or those with cardiovascular risk factors
• Cancers (including lymphoma): a small increased risk has been observed in JAK inhibitor studies

Blood tests for lipids, blood count, liver function, and kidney function are checked regularly.

• Probenecid: increases baricitinib levels. Dose adjustment may be needed
• Other immunosuppressants: increased infection risk
• Live vaccines: must not be given during treatment

Tell your doctor about all medicines you are taking.

What is the difference between Olumiant and biologic medicines like Humira?

Both treat rheumatoid arthritis by targeting the immune system, but they work differently. Humira (adalimumab) is an injectable biologic that blocks a protein called TNF-alpha outside cells. Olumiant (baricitinib) is an oral tablet that works inside cells by blocking JAK signalling pathways. JAK inhibitors like Olumiant are sometimes chosen when biologic injections have not worked well or when patients prefer a tablet. They have a different side effect and interaction profile and require similar monitoring.

I've heard JAK inhibitors can cause blood clots. How worried should I be?

Clinical studies have found an increased risk of blood clots (DVT and pulmonary embolism) and major cardiovascular events with baricitinib and other JAK inhibitors, particularly at higher doses and in people with existing risk factors such as older age, obesity, smoking, and cardiovascular disease history. Your doctor will assess your individual risk before prescribing and will monitor you during treatment. If you develop leg pain, swelling, or sudden shortness of breath, seek medical attention promptly.

Ace provides accurate and independent information medically reviewed on prescription medications. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment.