Generic Tacrolimus

Common use
Tacrolimus is an immunosuppressive medication used to prevent organ rejection in transplant patients, particularly after kidney, liver, or heart transplants. It works by inhibiting calcineurin, an enzyme crucial for activating T-cells in the immune system. By suppressing immune activity, tacrolimus helps the body accept a transplanted organ.

Dosage and direction
Tacrolimus is available in oral capsules, extended-release tablets, and intravenous forms. Dosage is highly individualized based on weight, organ type, and blood levels, and it is typically taken twice daily, 12 hours apart. It should be taken on an empty stomach at the same time each day to maintain consistent blood levels.

Precautions
Patients using tacrolimus must undergo regular blood tests to monitor kidney function, drug levels, and overall health. Avoid grapefruit or grapefruit juice while taking this medication, as it can increase drug levels in the blood. Extra caution is needed in patients with liver or kidney disease, diabetes, or electrolyte imbalances.

Contraindications
Tacrolimus is contraindicated in individuals with hypersensitivity to tacrolimus or other macrolide antibiotics. It should not be used by patients who cannot be closely monitored or are taking drugs that severely interfere with its metabolism. Pregnant or breastfeeding women should consult a doctor due to potential risks to the baby.

Possible side effect
Common side effects include tremors, headache, nausea, high blood sugar, and kidney dysfunction. Long-term use may increase the risk of infections, high blood pressure, and certain types of cancer, including lymphoma. Report any unusual symptoms such as changes in urination, persistent fatigue, or visual disturbances to a healthcare provider.

Drug interaction
Tacrolimus interacts with many drugs, including antifungals (like ketoconazole), antibiotics (like erythromycin), and anticonvulsants (like phenytoin), which can increase or decrease its blood levels. Inform your doctor about all medications and supplements, especially herbal products like St. John’s Wort. Careful monitoring is required when starting or stopping any interacting drugs.

Missed dose
If a dose is missed, take it as soon as you remember unless it is close to the next scheduled dose. Do not double up or take extra medication to compensate. Missing doses can reduce the effectiveness and increase the risk of organ rejection.

Overdose
Overdose may lead to serious symptoms such as kidney failure, seizures, or extreme immune suppression. Seek immediate medical help if overdose is suspected. Treatment involves supportive care and monitoring in a medical setting.

Storage
Store tacrolimus at room temperature, away from moisture, heat, and direct light. Keep capsules in their original packaging and tightly closed. Do not freeze or expose to excessive humidity; keep out of reach of children.

Short description
Tacrolimus is a powerful immunosuppressant used to prevent organ rejection following transplantation. It works by blocking immune responses that could attack the new organ. Available in oral and injectable forms, it requires careful monitoring of blood levels and kidney function. Due to potential side effects, it should be used exactly as prescribed.

Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. The specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.

Clinical Verification

Last Clinically Updated: August 15, 2026

Written By

Dr. Elena Vance, PharmD

Clinical Specialist in Neuropharmacology

Fact Checked By

Marcus Thorne, MS

Biomedical Data & FDA Label Verification

Medically Reviewed By

Dr. Arthur Campbell, MD

Board-Certified Psychiatrist (ABPN)