title: Effect of gastric acid suppression with pantoprazole on the efficacy of calcium carbonate as a phosphate binder in haemodialysis patients.
abstract: OBJECTIVE
  Metallic phosphate binders require acidity to dissociate to the free metallic ion and bind phosphorus. Altered gastric acidity may, therefore, influence phosphate-binding efficacy. We evaluated the clinical effect of pantoprazole on the efficacy of calcium carbonate phosphate binders in haemodialysis patients.
  
  
  METHODS
  The study had two parts: a cross-sectional study (n = 67), and an interventional, crossover, double-blind, randomized, placebo-controlled trial in 26 patients given pantoprazole 40 mg daily or placebo for two consecutive 6-week periods.
  
  
  RESULTS
  The cross-sectional study showed no difference between those on and off acid suppressants in phosphate (1.43 ± 0.45 vs 1.46 ± 0.31 mmol/L, P = 0.782) or other parameters except age (72.2 ± 9.8 vs 63.8 ± 14.8 years, P = 0.01). In the interventional study, phosphate was higher during pantoprazole than placebo (1.59 ± 0.3 vs 1.42 ± 0.3 mmol/L, P = 0.005). Serum calcium (2.37 ± 0.2 vs 2.46 ± 0.2 mmol/L, P = 0.012) and ionized calcium (1.17 ± 0.1 vs 1.22 ± 0.1 mmol/L, P = 0.013) were lower during pantoprazole treatment. CaxPO(4) (3.76 ± 0.7 vs 3.48 ± 0.7 mmol(2) /L(2) , P = 0.032) and intact parathyroid hormone (31.9 ± 21.4 vs 23.6 ± 17.7 pmol/L, P = 0.004) were higher on pantoprazole.
  
  
  CONCLUSIONS
  These results demonstrate clinical evidence for an adverse effect of gastric acid suppression on the effectiveness of calcium carbonate phosphate binders. Given their frequent co-prescription, this interaction may be a minor but common reason why some patients fail to control hyperphosphataemia. Clinicians should regularly assess the need for acid suppressants. Further studies are needed to investigate interactions with other phosphate binders.
authors.affiliation: Department of Pharmacy, Royal Adelaide Hospital, Adelaide, SA 5000, Australia. matthew.cervelli@health.sa.gov.au
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Cervelli
authors.forename: Ahmed
authors.initials: A
authors.lastname: Shaman
authors.forename: Anthony
authors.initials: A
authors.lastname: Meade
authors.forename: Robert
authors.initials: R
authors.lastname: Carroll
authors.forename: Stephen P
authors.initials: SP
authors.lastname: McDonald
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000009:adverse effects / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000097:blood; D002119:Calcium Carbonate / Q000009:adverse effects / Q000627:therapeutic use*; D002614:Chelating Agents / Q000009:adverse effects / Q000627:therapeutic use*; D018592:Cross-Over Studies; D003430:Cross-Sectional Studies; D004311:Double-Blind Method; D004347:Drug Interactions; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D054559:Hyperphosphatemia / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D000077402:Pantoprazole; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood*; D054328:Proton Pump Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D006435:Renal Dialysis / Q000009:adverse effects; D013021:South Australia; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D015415:Biomarkers; D002614:Chelating Agents; C470125:PTH protein, human; D010281:Parathyroid Hormone; D010710:Phosphates; D054328:Proton Pump Inhibitors; D000077402:Pantoprazole; D002119:Calcium Carbonate; D002118:Calcium