title: Pharmacokinetics of mycophenolate mofetil in Omani patients on cyclosporine or tacrolimus.
abstract: BACKGROUND
  Mycophenolate mofetil (MMF) reduces rejection in organ transplantation and is effective in controlling autoimmune diseases. Determining the area under the receiver operating characteristic curve (AUC) of MMF is not routine despite interindividual variability. The aim of this study was to look into MMF-AUC in Omani patients on cyclosporine (CsA) or tacrolimus (Tac).
  
  
  METHODS
  We measured MMF-AUC in 27 stable Omani patients. We used the 4-time-points-limited sampling strategy.
  
  
  RESULTS
  Sixteen, 8, and 3 recipients were receiving Tac, CsA, and calcineurin inhibitor (CNI)-free regimens, respectively. The mean MMF dose was 1,685 ± 442 mg/d. All except 3 patients were within or above the target AUC. The AUC was significantly higher in patients receiving Tac versus CsA. All patients on Tac were within or above the target AUC. Seven of the 8 patients with MMF-AUC above target were receiving Tac. Two of the 3 patients with MMF-AUC below target were on CsA.
  
  
  CONCLUSIONS
  These preliminary results confirm the significant interindividual variability of MMF-AUC. None of the recipients on Tac had an AUC below target. Most patients above the target AUC were receiving Tac. Two of the 3 patients with MMF-AUC below target were on CsA and receiving 1 g/d MMF. Patients on Tac are at risk of having higher than the target AUC, exposing them to overimmunosuppression. Recipients on CsA seem to require >1 g/d MMF.
  
  
  CONCLUSIONS
  These preliminary results encourage measuring the AUC of MMF. The fixed MMF dose regimen seems to be unreliable to predict the AUC. Preventing under- or overimmunosuppression offsets the burden.
authors.affiliation: Department of Medicine, Sultan Qaboos University, Muscat, Oman. Electronic address: nabilmohsin@gmail.com.
authors.forename: N
authors.initials: N
authors.lastname: Mohsin
authors.affiliation: Department of Pharmacy, Royal Hospital, Muscat, Oman.
authors.forename: F
authors.initials: F
authors.lastname: Al-Raisi
authors.affiliation: Department of Medicine, Sultan Qaboos University, Muscat, Oman.
authors.forename: E
authors.initials: E
authors.lastname: Militsala
authors.affiliation: Department of Medicine, Sultan Qaboos University, Muscat, Oman.
authors.forename: P
authors.initials: P
authors.lastname: Kamble
authors.affiliation: Department of Medicine, Sultan Qaboos University, Muscat, Oman.
authors.forename: E
authors.initials: E
authors.lastname: Abdel Razek
authors.affiliation: Department of Medicine, Sultan Qaboos University, Muscat, Oman.
authors.forename: M
authors.initials: M
authors.lastname: Baddruddin
mesh_terms: D000328:Adult; D065095:Calcineurin Inhibitors / Q000627:therapeutic use; D016572:Cyclosporine / Q000627:therapeutic use*; D005260:Female; D006084:Graft Rejection / Q000378:metabolism / Q000517:prevention & control*; D006801:Humans; D007168:IMP Dehydrogenase / Q000037:antagonists & inhibitors; D007166:Immunosuppressive Agents / Q000493:pharmacokinetics; D016030:Kidney Transplantation; D008297:Male; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D016559:Tacrolimus / Q000627:therapeutic use*
chemical_list: D065095:Calcineurin Inhibitors; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D007168:IMP Dehydrogenase; D009173:Mycophenolic Acid; D016559:Tacrolimus