Pattern and associated factors of potential drug-drug interactions in both pre- and early post-hematopoietic stem cell transplantation stages at a referral center in the Middle East.

The aim of this study was to determine the pattern as well as associated factors of moderate and major potential drug-drug interactions (PDDIs) in both the pre- and early post-transplantation stages at a referral hematopoietic stem cell transplantation (HSCT) center. All adolescents and adults undergone HSCT within a 3-year period were screened retrospectively for potential moderate or severe PDDIs by the Lexi-Interact On-Desktop software. Among 384 patients, a total of 13,600 PDDIs were detected. The median (interquartile range) cumulative PDDIs burden was 41 (28). All (100 %) individuals experienced at least one PDDI. More than four fifths (81.8 %) of detected PDDIs were moderate. The predominant mechanism of PDDIs was pharmacokinetics (54.3 %). Interaction between sulfamethoxazole-trimethoprim and fluconazole was the most common PDDIs involving 95.3 % of the study population. More than three fifths (61.5 %) of detected PDDIs were caused by HSCT-related medications. No interaction was identified between two anticancer agents. Interactions of cyclophosphamide with phenytoin, busulfan with metronidazole, dexamethasone, or clarithromycin were the only detected PDDI between anticancer and non-anticancer medications. Type of HSCT and the numbers of administered medications were significantly associated with major PDDIs. The epidemiology, real clinical consequence, and economic burden of DDIs on patients undergone HSCT particularly around the transplantation period should be assessed further by prospective, multicenter studies.