Title: REAL CLINICAL IMPACT OF DRUG-DRUG INTERACTIONS OF
IM-MUNOSUPPRESSANTS IN TRANSPLANT PATIENTS
Abstract
Aim: The main objective of this study was to determine the prevalence of
real DDIs between immunosuppressants and other drugs in transplant
patients. Methods: We conducted a prospective, observational 1-year
study at a tertiary hospital, including all transplanted patients. We
evaluated data from monitoring blood concentrations of immunosuppressive
drugs and adverse drug events (ADEs) caused by DDIs. The DDIs were
classified as C, D, or X according to their Lexi-Interact rating (C =
monitor therapy, D = consider therapy modification, X = avoid
combination). The clinical importance of real DDIs was expressed in
terms of patient outcomes. The data were analyzed using Statistical
Package for Social Sciences (SPSS) package v. 25.0 (IBM Corp., Armonk,
NY, USA). Results: A total of 309 transplant patients were included.
Their mean age was 52.0 ± 14.7 years (18–79) and 69.9% were male. The
prevalence of real DDIs was 21.7%. Immunosuppressive drugs administered
with anti-fungal azoles and tacrolimus (TAC) with nifedipine have a
great clinical impact. Real DDIs caused ADEs in 22 patients. The most
common clinical outcome was nephrotoxicity (1.6%; n=5), followed by
hypertension (1.3%; n=4). Suggestions for avoiding category D and X
DDIs included: changing the immunosuppressant dosage, using paracetamol
instead of non-steroidal anti-inflammatory drugs, and interrupting
atorvastatin. The number of drugs prescribed and having been prescribed
TAC was associated with an increased risk of real DDIs. Conclusion:
There are many potential DDIs described in the literature but only a
small percentage proved to be real DDIs, based on the patients´
outcomes.