Drug-drug interactions are an important cause of adverse drug events. The preventable or manageable nature of drug-drug interactions puts them at the center of interventions. Since hematopoietic stem cell transplantation is a challenging and multi-drug process, drug-drug interactions are frequently encountered.

In our study, the drugs used by a total of 100 patients with 50 autologous and 50 allogeneic bone marrow transplants for 10 days before transplantation, on the day of transplantation and for 10 days after transplantation were examined retrospectively in terms of interaction. Two paid softwares and two free softwares were used to examine interactions. The obtained data were analyzed with Microsoft Excel program.

A total of 3805 interactions were observed in the 21-day period in 50 patients who underwent allogeneic stem cell transplantation, and these interactions occurred with the repetition of 1017 interactions in different patients. For the same period in 50 autologous stem cell transplant patients, 2906 interactions were detected, and this number occurred with 725 different interactions seen in different patients.  It has been understood that anti-infectives cause serious interaction load.

Hematopoietic stem cell transplantation is a period in which prophylactic or anti-infective treatment for the detected microorganism is applied intensively. Interactions of anti-infectives with each other and with other drugs in the treatment regimen are frequently encountered during the transport process. Interactions should be identified and their clinical significance should be demonstrated. It should be handled  with the partnership of physician-clinical pharmacist.