The tolerability of newer immunosuppressive medications in a patient with acute intermittent porphyria

Acute intermittent porphyria results from a deficiency of the porphobilinogen deaminase enzyme of heine biosynthesis and is commonly exacerbated by a wide variety of medications. When referred a patient with acute intermittent porphyria for a renal transplant, only steroids and azathioprine were discovered as safe in patients with acute intermittent porphyria. The administration of many newer immunosuppressive medications, including calcineurin inhibitors, has not been documented in acute intermittent porphyria. Actually, cyclosporine is presently considered contraindicated in acute intermittent porphyria. To determine if calcineurin inhibitors would be tolerated in acute intermittent porphyria, cyclosporine and tacrolimus were administered pretransplant and were documented not to exacerbate acute intermittent porphyria. A successful renal transplant was then performed using tacrolimus. This is the first reported patient with documented acute intermittent porphyria to tolerate safely several of the newer immunosuppressive medications, including tacrolimus, mycophenolate, and rabbit antithymocytic globulin following renal transplantation. This patient's pretransplant evaluation also suggested that cyclosporine may be safe for some patients with acute intermittent porphyria. (C) 2001 the American College of Clinical Pharmacology.