Drug Interaction Report

Consumer information for this interaction is not currently available.

GENERALLY AVOID: Coadministration of topical tacrolimus with other immunosuppressive agents may potentiate the immunosuppressive effects of topical tacrolimus. However, data concerning its safety and efficacy in combination with immunosuppressants are not available. According to the prescribing information, rare cases of skin malignancy and lymphoma have been reported in patients who have received treatment with topical calcineurin inhibitors, including topical tacrolimus. On the other hand, systemic exposure from topical tacrolimus is reported to be less than 1 ng/mL. In addition, the lowest tacrolimus blood concentration from topical application at which systemic effects can be observed is unknown.

MANAGEMENT: According to the manufacturer, use of topical tacrolimus in immunocompromised patients is not recommended. Therefore, until further information is available, it may be advisable to avoid its concomitant use with other immunosuppressants. Screening for the development of malignancy during and after treatment may also be considered.

You should limit or avoid consumption of grapefruit and grapefruit juice during treatment with selpercatinib unless directed otherwise by your doctor. Grapefruit juice may increase the blood levels of selpercatinib. High levels of selpercatinib can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. You may be more susceptible if you have a heart condition called congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances (for example, magnesium or potassium loss due to severe or prolonged diarrhea or vomiting). The risk and/or severity of other side effects may also increase, including nausea, vomiting, constipation, diarrhea, rash, muscle and joint pain, swelling of arms or legs, liver problems, high blood pressure, and bleeding complications. Talk to your doctor if you experience intolerable or troublesome side effects, or you have other questions or concerns. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with selpercatinib. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.