There is a national drug shortage of generic tacrolimus that may or may not affect your ability to get your medications in the next few weeks. Please contact your pharmacy to find out how much supply they have and contact your transplant doctor to discuss options during the drug shortage. The supply of several brand-name tacrolimus formulations is not affected by this shortage. If you run out of medications, call your transplant center immediately. Skipping your immunosuppression can lead to organ rejection.