title: Clinically significant drug-drug interaction between tacrolimus and phenobarbital: the price we pay.
abstract: OBJECTIVE
  The case of a 57-year-old male who experienced acute renal transplant rejection due to subtherapeutic tacrolimus levels as a result of drug interaction with phenobarbital.
  
  
  CONCLUSIONS
  Drug interactions with tacrolimus due to its metabolism through the CYP 450 3A4 enzymatic pathway have led to several reports of altered tacrolimus levels, which can lead to acute rejection in renal transplant recipients. We describe the case of a 57-year-old male initiated on immunosuppressive therapy with tacrolimus in addition to his anticonvulsant medications.
  
  
  CONCLUSIONS
  Upon tacrolimus dose increases, discontinuation of carbamazepine, and minimization of phenobarbital dose, effective tacrolimus trough levels were achieved in our patient. Identification and elimination of such drug-drug interactions is necessary to assure adequate immunosuppression in renal transplant recipients.
authors.affiliation: Montefiore Medical Center, Department of Pharmacy, Bronx, NY 10467, USA.
authors.forename: Nida
authors.initials: N
authors.lastname: Siddiqi
authors.forename: Kwaku
authors.initials: K
authors.lastname: Marfo
mesh_terms: D000927:Anticonvulsants / Q000009:adverse effects / Q000737:chemistry / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D006084:Graft Rejection; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000737:chemistry / Q000627:therapeutic use*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010634:Phenobarbital / Q000009:adverse effects / Q000737:chemistry / Q000627:therapeutic use*; D016559:Tacrolimus / Q000009:adverse effects / Q000737:chemistry / Q000627:therapeutic use*
chemical_list: D000927:Anticonvulsants; D007166:Immunosuppressive Agents; D016559:Tacrolimus; D010634:Phenobarbital