This medication belongs to the class of medications called disease-modifying antirheumatic agents. Baricitinib is used alone or in combination with methotrexate to reduce the signs and symptoms of moderate-to-severely active rheumatoid arthritis (RA). It is used when treatment with one or more disease-modifying antirheumatic medications has not provided enough relief. It may also be used to treat severe alopecia areata in adults.

Rheumatoid arthritis (RA) is an autoimmune disease. This means that the body's immune system fails to recognize its own tissue, and views it as a foreign invader. In the case of RA, the immune system attacks the joints and tissue, causing long-term damage.

Alopecia areata is a condition that causes temporary patches of hair loss which sometimes occurs as a result of immune system problems.

Baricitinib is believed to work by interfering with the activity of an enzyme that sends inflammatory signals in the body called Janus Kinase. Baricitinib attaches to this enzyme which helps to reduce swelling and joint tenderness in people with RA.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose of this medication to treat rheumatoid arthritis is one 2 mg tablet taken by mouth once daily. It may be taken with food or on an empty stomach.

When treating alopecia areata, the usual starting dose is 2 mg daily, which may be increased to 4 mg daily, depending on how well the lower dose works.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor.

If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

2 mg
Each light pink, film-coated, oblong tablet with a recessed area on each face of the tablet surface, debossed with "Lilly" on one side and "2" on the other, contains 2 mg of baricitinib. Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate, mannitol, and microcrystalline cellulose; colour coating: ferric oxide, lecithin (soya), polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

4 mg
Each medium pink, round, film-coated tablet, with a recessed area on each face of the tablet surface, debossed "Lilly" on one side and "4" on the other, contains 4 mg of baricitinib. Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate, mannitol, and microcrystalline cellulose; colour coating: ferric oxide, lecithin (soya), polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

Do not take this medication if you:

• are allergic to baricitinib or any ingredients of the medication
• are or may become pregnant

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• acne
• cold sores
• cold- and flu symptoms (e.g., achiness, cough, runny nose, sinus congestion, sore throat)
• constipation
• diarrhea
• dizziness
• fatigue
• headaches
• heartburn
• joint pain
• mouth and throat pain
• muscle spasms
• nausea
• rash
• sinus infection
• stomach pain
• trouble sleeping
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• cancers affecting different parts of the body
• increased blood pressure
• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• skin infection (e.g., red, swollen or painful skin)
• new skin lesions or change in appearance of existing skin lesions
• swelling of the face
• symptoms of bronchitis (e.g., cough, tiredness, shortness of breath)
• symptoms of muscle damage (e.g., unexplained muscle pain, tenderness or weakness, or brown or discoloured urine)
• symptoms of pneumonia (e.g., coughing, fever, fatigue)
• symptoms of shingles (e.g., skin rash or blisters with itching, burning or tingling pain, usually on one side of the body)
• symptoms of stomach or bowel infection (e.g., vomiting, stomach pain, watery or bloody diarrhea, loss of appetite)
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)
• vaginal yeast infections (e.g., itching, burning, soreness, whitish-grey cottage cheese-like discharge)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worst when breathing in, coughing, coughing up blood, sweating, or passing out)
• symptoms of heart attack (e.g., sudden chest pain or pain radiating to back, down arm, jaw; sensation of fullness of the chest; nausea; vomiting; sweating; anxiety)
• symptoms of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Blood cholesterol: Baricitinib has been associated with increased blood cholesterol levels. If you have elevated blood cholesterol levels, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Blood clots: This medication may increase the chance of blood clot formation, causing reduction of blood flow to organs or the extremities.

If you experience symptoms such as sharp pain and swelling in the leg, difficulty breathing, chest pain, blurred vision or difficulty speaking, contact your doctor immediately.

Cancer: Rarely, people taking baricitinib and similar medications have developed cancer, including lymphoma, non-melanoma skin cancer, and lung cancer. In general, people with rheumatoid arthritis who take medications that suppress the immune system over long periods of time may also have a higher risk of developing lymphoma, even if they don't take baricitinib.

Discuss any concerns you have with your doctor.

Gastrointestinal perforation: People who take anti-inflammatory medications such as NSAIDs or corticosteroids while they are also taking baricitinib may be more at risk of experiencing a tear in the lining of the stomach, which can cause serious bleeding. This can occur without abdominal pain.

If you notice bloody or black and tarry stools, or vomit blood or material that looks like coffee grounds, seek medical help immediately.

Heart attack and stroke: Baricitinib may increase the risk for major heart problems such as heart attack and stroke. If you have risk factors for heart disease such as high blood pressure, high cholesterol, or are a smoker or have a history of smoking your risk may be increased.

If you experience symptoms such as chest pain, difficulty breathing, pain extending through shoulder and arm, nausea and vomiting, sweating, weakness on one side of the body, or slurred speech, get immediate medical attention.

Infection: This medication reduces your body's response to infection. People taking baricitinib are at an increased risk of developing serious infections that can be difficult to treat and may cause hospitalization or death. These infections include tuberculosis and fungal infections, as well as infections caused by bacteria and viruses. These infections are more likely to occur if you are taking another medication that reduces the activity of the immune system.

If you have been exposed to tuberculosis, have a history of serious or recurrent infections or have medical conditions that may increase the likelihood of developing infections, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If possible, avoid contact with people with contagious infections. Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness.

Kidney function: Decreased kidney function may cause baricitinib to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function:  People taking baricitinib may have changes in liver function that produce abnormal liver test results. Your doctor will recommend regular liver tests while you are taking this medication. If you have a history of hepatitis B infection, it is possible that this infection may flare up while taking baricitinib.

If you experience symptoms of liver problems, such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

People with severely reduced liver function should not use this medication.

Lung inflammation: Lung inflammation (interstitial lung disease), causing difficulty breathing has occurred in some people taking this medication. This complication can be serious and sometimes fatal.

If you experience new or worsening shortness of breath or cough (with or without fever) at any time while you are taking baricitinib contact your doctor immediately.

Vaccinations: People taking this medication should not receive certain vaccines. Talk to your doctor about whether any vaccines you are scheduled to take may be used with this medication.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. People who are of childbearing age should use appropriate birth control while taking baricitinib and for at least 1 week after taking the last dose of medication.

Breast-feeding: It is not known if baricitinib passes into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

Seniors: People over the age of 65 years may be more at risk of side effects from this medication.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.