title: Clinical hypotension with co-prescription of macrolide antibiotics and calcium-channel blockers in haemodialysis patients: a retrospective chart review.
abstract: BACKGROUND
  Macrolide antibiotics inhibit the cytochrome p450 enzyme system, which metabolizes calcium-channel blockers. This may result in a clinically significant interaction, causing hypotension in patients co-prescribed these two drugs. Since these drugs are frequently used in the haemodialysis population, we studied the effect of their co-prescription on actual blood pressure.
  
  
  METHODS
  A retrospective chart review of all haemodialysis patients was conducted to identify patients co-prescribed a macrolide and a dihydropyridine calcium-channel blocker. Blood pressure measurements before and during the macrolide co-prescription were abstracted and compared using a student's t test.
  
  
  RESULTS
  We identified 154 haemodialysis patients concurrently prescribed a macrolide antibiotic and a dihydropyridine calcium-channel blocker. There was no significant difference in episodes of intra-dialytic hypotension or actual blood pressure measurements in the period before macrolide co-prescription and the period during macrolide co-prescription.
  
  
  CONCLUSIONS
  In contrast to hospitalized patients receiving dihydropyridine calcium-channel blockers, concurrent administration of a macrolide antibiotic for infection did not result in hypotension in haemodialysis outpatients. Further research should be undertaken before a change in clinical practice against their co-prescription is considered.
authors.affiliation: The Renal Hypertension Unit, Division of Nephrology, Department of Medicine, University of Ottawa, Ottawa, ON, Canada, shiremath@toh.on.ca.
authors.forename: Swapnil
authors.initials: S
authors.lastname: Hiremath
authors.forename: Marcel
authors.initials: M
authors.lastname: Ruzicka
authors.forename: Shankar Prasad
authors.initials: SP
authors.lastname: Nagaraju
authors.forename: Brendan B
authors.initials: BB
authors.lastname: McCormick
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D004095:Dihydropyridines / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D004347:Drug Interactions; D011307:Drug Prescriptions / Q000592:standards; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D007022:Hypotension / Q000139:chemically induced* / Q000378:metabolism; D018942:Macrolides / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D008297:Male; D006435:Renal Dialysis; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D018942:Macrolides