Abrocitinib belongs to the class of medications called selective immunomodulators. Specifically, it is in the family of Janus Kinase 1(JAK) inhibitors. It is used to treat moderate-to-severe atopic dermatitis in adolescents and adults when other non-topical medications haven't been effective or cannot be used.

This medication works by blocking an enzyme called Janus kinase, a chemical in the body that starts the immune response. This immune response causes swelling, redness, itching, and pain. Abrocitinib reduces this immune response and the inflammation that occurs with dermatitis.

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 usual dose of abrocitinib is 100 mg to 200 mg taken by mouth once daily, at the same time each day. It may be taken with or without food, however taking it with food may help reduce nausea. Swallow the tablets whole with water. Do not chew, crush, or split the tablets. If a tablet is cracked, crushed, or split, do not take the tablet.

This dose is used for 12 weeks, after which, your doctor may suggest reducing the dose to the lowest effective dose. Decreasing the dose appears to help reduce the risk of serious adverse reactions.

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 less than 12 hours until 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.

50 mg
Each film-coated tablet contains 50 mg of abrocitinib. Nonmedicinal ingredients: dibasic calcium phosphate anhydrous, hypromellose, iron oxide, lactose monohydrate, magnesium stearate, microcrystalline cellulose, sodium starch glycolate, Macrogol/PEG, titanium dioxide, and triacetin.

100 mg
Each film-coated tablet contains 100 mg of abrocitinib. Nonmedicinal ingredients: dibasic calcium phosphate anhydrous, hypromellose, iron oxide, lactose monohydrate, magnesium stearate, microcrystalline cellulose, sodium starch glycolate, Macrogol/PEG, titanium dioxide, and triacetin.

200 mg
Each film-coated tablet contains 200 mg of abrocitinib. Nonmedicinal ingredients: dibasic calcium phosphate anhydrous, hypromellose, iron oxide, lactose monohydrate, magnesium stearate, microcrystalline cellulose, sodium starch glycolate, Macrogol/PEG, titanium dioxide, and triacetin.

Do not take this medication if you are allergic to abrocitinib or any ingredients of the medication.

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 (also known as oral herpes simplex)
• dizziness
• headache
• nausea
• upper abdominal pain
• 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:

• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• 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 pneumonia (e.g., fever, chills, shortness of breath, cough)
• signs of skin cancer (e.g., open sores that do not heal, growths on the skin that are irregularly shaped or changing colour)
• symptoms of herpes simplex (e.g., tingling, itching pain in genital area, small red blisters or sores on penis, pain, swelling around eyes, cold sores)
• symptoms of shingles (herpes zoster; e.g., painful skin rash, fluid-filled blisters along a strip of skin, itching, tingling skin)

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

• 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)
• signs of a heart attack (e.g., chest pain or pressure, pain extending through shoulder and arm, nausea and vomiting, sweating)

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 clots: This medication may increase the chance of blood clot formation, causing reduction of blood flow to organs or the extremities. If you have a history of clotting you may be at increased risk of experiencing blood clot-related problems such as heart attack, stroke, or clots in the deep veins of your leg. 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 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: Although not common, abrocitinib has been associated with several different types of cancer including lymphoma and non-melanoma skin cancer. Discuss any concerns that you may have with your doctor.

Cholesterol: Abrocitinib can cause increased blood cholesterol levels.   Your doctor will check your cholesterol prior to starting treatment and during treatment with abrocitinib.

Driving/Operating Machinery: Abrocitinib may cause dizziness, affecting your ability to drive or operate machinery. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how you are affected by this medication.

Infection: This medication can increase the risk of developing serious infections such as  pneumonia, chicken pox, fungal infections, and tuberculosis.  Before starting treatment with abrocitinib, your doctor may test to see if you have had tuberculosis or hepatitis. People taking abrocitinib have a higher risk of reactivation of these infections, as well as other viral infections including herpes simplex (cold sores), or herpes zoster (shingles).

If you notice signs of an infection such as fever, chills, pain, swelling, coughing, or pus, contact your doctor as soon as possible. This medication should also not be started while you have an active infection. Abrocitinib should not be used in combination with certain other medications that suppress the immune system, as this can increase the risk of severe infection.

Kidney function: People who have reduced kidney function may require lower doses of this medication. 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.

Vaccines: Live vaccines such as yellow fever, BCG, and cholera should not be given while you are taking abrocitinib.  Other vaccines may not be as effective when given during treatment with medications like abrocitinib. It is advisable to make sure all your vaccines are up-to-date before starting this medication.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. Women who may become pregnant should use effective birth control while taking abrocitinib and for at least 1 month after stopping the medication. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if abrocitinib passes into breast milk. If you are a breast-feeding mother 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 under 12 years of age.

Seniors: People over the age of 65 years may be more likely to experience a recurrence of herpes zoster while taking abrocitinib.

There may be an interaction between abrocitinib and any of the following:

• aliskiren
• anagrelide
• antipsychotics (e.g., clozapine, risperidone)
• apalutamide
• "azole" antifungals (e.g., fluconazole, voriconazole)
• bilastine
• clopidogrel
• colchicine
• dabigatran
• deferiprone
• digoxin
• dipyridamole
• edoxaban
• glecaprevir and pibrentasvir
• lumacaftor and ivacaftor
• medications that suppress the immune system:
• corticosteroids (e.g., dexamethasone, hydrocortisone, prednisone)
• medications used to treat conditions such as cancer, inflammatory bowel disease, multiple sclerosis, psoriasis, rheumatoid arthritis, or medications used after a transplant
• moclobemide
• morphine
• naloxegol
• non-steroidal anti-inflammatory medications (NSAIDs; e.g., diclofenac, ibuprofen, ketorolac, naproxen)
• prasugrel
• protein kinase inhibitors (e.g., dasatinib, idelalisib, imatinib)
• ranolazine
• rifampin
• rifaximin
• romidepsin
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline, vortioxetine)
• serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., desvenlafaxine, duloxetine, venlafaxine)
• silodosin
• stiripentol
• tenofovir
• ticagrelor
• vaccines

If you are taking any of these 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.

Medications other than those listed above may interact with this medication. 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.