Immunosuppressant medication Mechanism of immunosuppressant action Endocrine dysfunction
Tacrolimus (FK506)/ Cyclosporine Calcineurin inhibition
  1. Hyperglycemia: Beta cell toxicity, decreased insulin secretion and insulin sensitivity PTDM [16,21,22,26,28,29].
  2. Hypogonadism/oligospermia: rarely [53].
  3. Low bone density: Cyclosporine has strong evidence while TAC has equivocal effects [60-62,64].
 
Sirolimus (rapamycin) mTOR inhibition
  1. Hyperglycemia: Insulin resistance and beta cell toxicity [14-16,37].
  2. Primary hypogonadism in men and rarely reduced sperm counts [54-58].
  3. May impair fracture healing [67].
                                                       
Table 1: Summary of effects of TAC and SIR on endocrine system