Evaluation of Electrolyte Repletion and Infection Rates in Hematopoietic Cell Transplant Patients Receiving H-2 Receptor Antagonists or Proton Pump Inhibitors

At Virginia Commonwealth University Health System, hematopoietic cell transplant (HCT) patients receive proton pump inhibitors (PPI) during their admission to prevent chemotherapy-induced gastroduodenal injury.  Prior to 2012, most patients were also discharged on PPI to reduce the frequency of ulcers and upper gastrointestinal (GI) symptoms after HCT.

Adverse effects of PPI therapy may include magnesium deficiency, ^1,2  increases in Clostridium difficile infection,³  and an increased risk of community-acquired pneumonia.⁴    Compared to PPI therapy, H-2 receptor antagonists (H2RA) have less pronounced and prolonged acid suppression which contributes to an advantageous side effect profile. Since HCT patients are subject to low electrolyte levels⁵ and increased risks of infection at baseline, we sought to determine the association between PPI use and electrolyte repletion and infection rates and whether the use of H2RA was associated with reduced risk of these complications.

A retrospective, matched cohort study was conducted from September 30, 2010 through March 31, 2013. Patients 18 years or older receiving H2RA therapy post-HCT admission were matched by transplant type and preparatory regimen to patients receiving PPI.  Matched pairs were evaluated for four weeks post-discharge.   In addition to baseline characteristics, data collected included the amount and frequency of electrolyte repletion via a standard institutional protocol, rates of infection (positive cultures, use of antibiotics, radiologic evidence of pneumonia), and patient-reported GI symptoms. Data were analyzed with descriptive statistics, paired t-tests, and McNemar’s Chi square test.

Twenty-six matched pairs were included. Patients receiving PPI required significantly more magnesium repletion in weeks 1, 3, and 4 post-discharge. During weeks 1, 3, and 4, significantly more patients receiving H2RA therapy went an entire week without repletion versus patients receiving PPI. Although the magnitude or frequency of potassium or calcium repletion were generally higher among PPI users, these differences were not statistically significant. The number of patients with evidence of infection was not significantly different between groups. Compared to patients on H2RA therapy, significantly more patients receiving PPI reported GI symptoms.

H2RA therapy deserves serious consideration in place of PPI, when possible, for HCT patients post-discharge.

References:

1. Arch Intern Med 2011;171(15):1391-2.

2. Am J Kidney Dis 2010;56(1):112-6.

3. Arch Intern Med 2010;170(9):772-8.

4. JAMA 2004;292(16):1955-60.

5. Nephrol Dial Transplant 2008; 23: 359-363.