Baricitinib is used to treat rheumatoid arthritis. It helps decrease pain, tenderness, and swelling in the joints. It is also used to treat a certain immune disorder which causes hair loss (alopecia areata).

In the US, baricitinib is also being used to treat coronavirus disease (COVID-19). It is used in certain patients in the hospital who need supplemental oxygen (including patients on a mechanical ventilator).

Read the Medication Guide provided by your pharmacist before you start taking baricitinib and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor, usually once daily.

If you have trouble swallowing this medication whole, you may place your dose in a cup with about 2 teaspoonful (10 milliliters) of room temperature water to dissolve the tablet(s). Stir the mixture gently and then drink all of it right away. Rinse the cup with another 2 teaspoonful (10 milliliters) of water and drink the rinse water to make sure you get all of your dose.

The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.

Tell your doctor if your condition does not get better or if it gets worse.

See also Warning section.

People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.

Tell your doctor right away if you have any serious side effects, including:

• signs of anemia (such as unusual tiredness, pale skin, fast heartbeat)
• signs of liver disease (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine)
• signs of a serious tear in the stomach or intestinal wall (such as severe stomach/abdominal pain that doesn't go away, fever, severe dizziness, fainting, severe nausea/vomiting)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

See also Warning section.

Before taking baricitinib, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• blood clots (such as in the lungs, legs)
• heart problems (such as previous heart attack)
• stroke
• current or past smoking
• blood/bone marrow problems (such as anemia)
• cancer
• kidney disease
• liver disease (such as hepatitis B or C)
• past/recent/current infections (such as tuberculosis, herpes zoster, HIV infection)
• stomach/intestinal problems (such as ulcers, diverticulitis)

Baricitinib can make you more likely to get infections or may make current infections worse. Stay away from anyone who has an infection that may easily spread (such as chickenpox, COVID-19, measles, flu). Talk to your doctor if you have been exposed to an infection or for more details.

Tell your health care professional that you are using baricitinib before having any immunizations/vaccinations. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Because of the possible risk to the infant, breastfeeding is not recommended while taking this medication and for at least 4 days after the last dose. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as liver/kidney function, complete blood count, cholesterol levels, skin exams) should be done while you are taking this medication. Keep all medical and lab appointments.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).