The purpose of this study is to verify whether differences exist in cyclosporine levels between the samples collected through peripheral venous access, the catheter line used to infuse the drug and the line not used for infusion immediately after interrupting the drug infusion or five minutes after the interruption.

Cyclosporine is an immunosuppressant that prevents graft-versus-host disease, has a narrow therapeutic window, and causes nephrotoxicity. For cyclosporine infusion, a tunneled central venous access device is used; however due to the lipophilic properties of the drug, it can adsorb to the catheter surface and falsely raise cyclosporine concentrations in blood specimens. Some authors recommend sample collection through peripheral access only. Others, however, have shown that these can be collected through the catheter line not used to infuse the drug. Controversies still exist, though, regarding the best timing and blood volume to be discarded to collect the sample.

The hypothesis adopted was that drug adsorption occurs in the line used for infusion. Therefore, there is no statistical or clinical difference between the blood sample collected from the peripheral venous access and from the line not used for cyclosporine infusion. Additionally, this difference becomes smaller when waits five minutes between the interruption of the infusion of the drug and the collection of the blood sample.

Inclusion Criteria:

• Patients older than 18 years of age who are receiving an allogeneic hematopoietic stem cell transplantation;
• Have a tunneled central venous access device with at least two lines implanted;
• Received cyclosporine administration through this device.

Exclusion Criteria:

• Patients who received cyclosporine infusion through a catheter line other than the one established for this goal.