tacrolimus and Tachycardia

The aim of this paper was to report the case of type 2 diabetes and significant insulin resistance that improved dramatically after removal of a pheochromocytoma in a liver transplant recipient , and to provide a review of the relevant literature. We describe the clinical presentation, diagnostic results and management of the patient. In addition, we performed a PubMed search for related English language articles, to provide an overview of the pertinent literature. A 53 year old woman with a history of an orthotopic liver transplantation and insulin-requiring type 2 diabetes was admitted to the hospital with fever, diaphoresis, tachycardia and hypertension. A pheochromocytoma was diagnosed and removed. The patient subsequently developed hypoglycemia and required no further insulin therapy. Pheochromocytomas have been described to lead to hyperglycemia and diabetes, due to the suppression of insulin release and increased insulin resistance. Furthermore, a review of the literature revealed only 3 other reported cases of pheochromocytomas in organ transplant recipients. None of these pheochromocytomas were believed to have occurred de novo after transplantation. This is the first report of a pheochromocytoma in a liver transplant recipient and possibly the first case of a de novo pheochromocytoma in any organ transplant recipient. Moreover, this case showcases pheochromocytomas as a rare cause of diabetes mellitus.

Topics: Adrenal Gland Neoplasms; Adrenalectomy; Diabetes Mellitus, Type 2; Female; Glipizide; Glucocorticoids; Humans; Hypertension; Hypoglycemic Agents; Immunosuppressive Agents; Insulin; Insulin Resistance; Insulin Secretion; Liver Diseases, Alcoholic; Liver Transplantation; Middle Aged; Pheochromocytoma; Postoperative Complications; Remission Induction; Tachycardia; Tacrolimus

Hepatic metabolism of sildenafil uses the same metabolic pathway as the calcineurin inhibitors (cyclosporine/tacrolimus), through the CYP3A4 isoenzyme. The aim of this pilot study was to evaluate the potential interaction between sildenafil therapy and circulating levels of cyclosporine and tacrolimus in a group of steady-state renal transplant recipients with erectile dysfunction.. A prospective pilot study of sildenafil interactions was carried out in 9 stable male renal transplant recipients with severe erectile dysfunction (mean age 50 +/- 8 years, range 38-64). All patients were receiving therapy with calcineurin inhibitors (5 with cyclosporine and 4 with tacrolimus). Erectile dysfunction was evaluated by clinical history, physical examination, International Index of Erectile Function (IIEF) questionnaire and the nocturnal penile tumescence test (RigiScan). Each patient received a first dose of 50 mg of sildenafil, one hour before sexual activity and a second dose at 72 hours of 50 or 100 mg according to the clinical response to the first dose. We evaluated the efficacy and safety of sildenafil and the evolution of cyclosporine-tacrolimus levels. Cyclosporine and tacrolimus trough whole blood concentrations were determined in basal conditions (before starting sildenafil) and on days 1, 4 and 7 after sildenafil therapy.. Eighty-nine percent of patients (n = 8) required a complete 100 mg dose of sildenafil. There was a positive clinical response in two-thirds of cases (6 patients). In 5 patients (55%) sildenafil administration produced a complete response, in one patient the response was incomplete, and in the remaining 3 cases (33%) no clinical response was observed. Associated side effects included self-limited tachycardia in one patient and mild visual disturbances in another. Cyclosporine and tacrolimus levels remained stable in all patients. There were no significant differences in circulating levels of cyclosporine (basal 120 +/- 47; day 1: 116 +/- 55; day 4: 123 +/- 56 and day 7: 121 +/- 56 ng/ml p = NS) or tacrolimus (basal 11.6 +/- 1.3; day 1: 11.9 +/- 1.3; day 4: 11.1 +/- 1.0 and day 7: 11.8 +/- 0.9 ng/ml p = NS) over the study period.. Sildenafil therapy is safe and effective for the treatment of erectile dysfunction in renal transplant recipients. Recommended therapeutic doses of sildenafil did not modify cyclosporine and tacrolimus trough blood levels.

Topics: Adult; Calcineurin Inhibitors; Cyclosporine; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; Drug Interactions; Erectile Dysfunction; Graft Rejection; Humans; Immunosuppressive Agents; Inactivation, Metabolic; Kidney Transplantation; Male; Microsomes, Liver; Middle Aged; Pilot Projects; Piperazines; Purines; Safety; Sildenafil Citrate; Sulfones; Tachycardia; Tacrolimus; Treatment Outcome; Vasodilator Agents