Several other drugs also showed efficacy in treatment of PTE in renal transplant recipients: theophylline, a nonselective adenosine receptor antagonist, can be used as an alternative mode of therapy of PTE; ketanserin, an antagonist of peripheral 5-HT2 receptors, can lower plasma erythropoietin levels in some chronic hemodialysis patients; and sirolimus, an immunosuppressant agent that causes marrow suppression and anemia, can be used to help treat PTE (Charfeddine et al., 2008). This evidence concerns the gene EPO and anemia (phenotype).