Tacrolimus is used with other medications to prevent rejection of a kidney, heart, liver, or lung transplant. The injection form of the medication is used when you cannot take the medication by mouth. As soon possible, your doctor will switch you to the form of this medication that is taken by mouth. This medication belongs to a class of drugs known as immunosuppressants. It works by weakening your body's defense system (immune system) to help your body accept the new organ as if it were your own.

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used for a certain type of bowel condition (severe fulminant Crohn's disease) in people who have not been successfully treated by the usual treatment.

This medication is given by injection into a vein by a health care professional.

The dosage is based on your weight, medical condition, lab tests (such as tacrolimus trough levels), and response to treatment.

Tell your doctor if your condition gets worse.

See also Warning section.

Shaking (tremor), headache, diarrhea, nausea/vomiting, upset stomach, loss of appetite, trouble sleeping, or numbness/tingling hands/feet may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

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

• signs of kidney problems (such as change in the amount of urine)
• mental/mood changes (such as anxiety, agitation)
• pounding heartbeat
• symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain)
• muscle spasm/weakness
• hearing problems (such as hearing loss, ringing in the ears)
• pain/redness/swelling at injection site or in the arms/legs
• dizziness
• easy bruising/bleeding
• signs of liver problems (such as nausea/vomiting that doesn't stop, yellowing eyes/skin, dark urine, stomach/abdominal pain)
• severe leg pain

This medication may also increase your risk of getting a rare but very serious (sometimes fatal) brain infection (progressive multifocal leukoencephalopathy-PML). Get medical help right away if any of these rare but very serious side effects occur:

• clumsiness
• loss of coordination
• weakness
• sudden change in your thinking (such as confusion, difficulty concentrating)
• difficulty moving your muscles
• problems with speech
• seizure
• vision changes

Get medical help right away if you have any very serious side effects, including:

• fainting
• fast/irregular heartbeat
• severe dizziness
• chest pain
• black stools
• vomit that looks like coffee grounds

This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high. Your doctor may control your blood pressure with medication.

Tacrolimus may cause diabetes. Tell your doctor or pharmacist if you experience any of the following symptoms of high blood sugar: increased thirst/hunger, frequent urination.

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.

Before receiving tacrolimus, tell your doctor or pharmacist if you are allergic to it; or to other macrolide medications (such as sirolimus); or if you have any other allergies. This product may contain inactive ingredients (such as polyoxyl 60 hydrogenated castor oil), 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:

• kidney disease
• liver disease
• high blood pressure
• diabetes
• mineral imbalances (such as high potassium)
• any recent/current infections
• cancer

Tacrolimus may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using tacrolimus, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions:

• certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG)
• family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death)

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using tacrolimus safely.

This medication may increase your risk of developing skin cancer. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors.

Tacrolimus 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 tacrolimus before having any immunizations/vaccinations. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

This drug may increase your potassium levels. Before using potassium supplements or salt substitutes containing potassium, consult your doctor or pharmacist.

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

Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using tacrolimus. Tacrolimus may harm an unborn baby. Men and women using this medication should ask about reliable forms of birth control before and during treatment. If you or your partner becomes pregnant, talk to your doctor right away about the risks and benefits of this medication.

This drug passes into breast milk and the effect on a nursing infant is unknown. 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.

Some products that may interact with this drug include:

• cyclosporine
• sirolimus
• temsirolimus
• ziprasidone
• other drugs that may increase the level of potassium in the blood (such as "water pills" including amiloride, spironolactone)
• other drugs that weaken the immune system/increase the risk of infection (such as natalizumab, rituximab)

Other medications can affect the removal of tacrolimus from your body, which may affect how tacrolimus works. Examples include azole antifungals (such as itraconazole, voriconazole), cimetidine, danazol, ethinyl estradiol, methylprednisolone, nefazodone, HIV protease inhibitors (such as nelfinavir), rifamycins (such as rifampin, rifabutin), ritonavir, St. John's wort, certain anti-seizure drugs (such as phenobarbital, phenytoin), among others.

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.

Lab and/or medical tests (such as potassium levels, blood pressure, blood sugar, tacrolimus blood level, kidney/liver function) will be done while you are using this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you have had an organ transplant, it is recommended that you attend a transplant education class or support group. Learn the signs of organ rejection such as tenderness/pain around the transplanted organ, a feeling of being ill, or fever. Tell your doctor right away if you notice any of these signs.

It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule.

Not applicable. This medication is given in a clinic and will not be stored at home.

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).