title: Proton pump inhibitors reduce mycophenolate exposure in heart transplant recipients-a prospective case-controlled study.
abstract: This prospective study investigates the impact of proton pump inhibitors (PPI) on mycophenolic acid (MPA) pharmacokinetics in heart transplant recipients receiving mycophenolate mofetil (MMF) and tacrolimus. MPA plasma concentrations at baseline (C(0 h)), 30 min (C(0.5 h)), 1(C(1 h)) and 2 h (C(2 h)) were obtained by high-performance liquid chromatography (HPLC) in 22 patients treated with pantoprazole 40 mg and MMF 2000 mg. Measurements were repeated 1 month after pantoprazole withdrawal. A four-point limited-sampling strategy was applied to calculate the MPA area under the curve (MPA-AUC). Predose MPA concentrations with PPI were 2.6 +/- 1.6 mg/L versus 3.4 +/- 2.7 mg/L without PPI (p = ns). Postdose MPA concentrations were lower with PPI at C(0.5 h) (8.3 +/- 5.7 mg/L vs. 18.3 +/- 11.3 mg/L, p = 0.001) and C(1 h) (10.0 +/- 5.6 mg/L vs. 15.8 +/- 8.4 mg/L, p = 0.004), without significant differences at C(2 h) (8.3 +/- 6.5 mg/L vs. 7.6 +/- 3.9 mg/L). The MPA-AUC was significantly lower with PPI medication (51.2 +/- 26.6 mg x h/L vs. 68.7 +/- 30.3 mg x h/L; p = 0.003). The maximum concentration of MPA (MPA-C(max)) was lower (12.2 +/- 7.5 mg/L vs. 20.6 +/- 9.3 mg/L; p = 0.001) and the time to reach MPA-C(max) (t(max)) was longer with PPI (60.0 +/- 27.8 min vs. 46.4 +/- 22.2 min; p = 0.05). This is the first study to document an important drug interaction between a widely used immunosuppressive agent and a class of drugs frequently used in transplant patients. This interaction results in a decreased MMF drug exposure which may lead to patients having a higher risk for acute rejection and transplant vasculopathy.
authors.affiliation: Department of Cardiac Surgery, University Hospital Grosshadern, Ludwig Maximilians University Munich, Munich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Kofler
authors.forename: N
authors.initials: N
authors.lastname: Shvets
authors.forename: A K
authors.initials: AK
authors.lastname: Bigdeli
authors.forename: M A
authors.initials: MA
authors.lastname: König
authors.forename: P
authors.initials: P
authors.lastname: Kaczmarek
authors.forename: M-A
authors.initials: MA
authors.lastname: Deutsch
authors.forename: M
authors.initials: M
authors.lastname: Vogeser
authors.forename: G
authors.initials: G
authors.lastname: Steinbeck
authors.forename: B
authors.initials: B
authors.lastname: Reichart
authors.forename: I
authors.initials: I
authors.lastname: Kaczmarek
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000008:administration & dosage / Q000009:adverse effects; D000208:Acute Disease; D000328:Adult; D016022:Case-Control Studies; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D005260:Female; D006084:Graft Rejection / Q000209:etiology; D016027:Heart Transplantation / Q000502:physiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology; D000077402:Pantoprazole; D011446:Prospective Studies; D054328:Proton Pump Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects*; D012307:Risk Factors; D016559:Tacrolimus / Q000008:administration & dosage
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D007166:Immunosuppressive Agents; D054328:Proton Pump Inhibitors; D000077402:Pantoprazole; D009173:Mycophenolic Acid; D016559:Tacrolimus