The efficacy of calcium carbonate in the treatment of protease inhibitor-induced persistent diarrhea in HIV-infected patients.

Although some evidence exists to support the practice of using calcium carbonate to treat nelfinavir-induced diarrhea, there is a lack of data supporting the role of calcium in diarrhea induced by other protease inhibitors (PIs). The objective of this prospective open-label study is to evaluate the efficacy of calcium carbonate in the treatment of PI-induced persistent diarrhea in HIV-infected patients. Along with dietary advice, patients were asked to take oral calcium carbonate 500 mg twice daily for 2 weeks. Visual Analog Scale (VAS) and the National Cancer Institute of Canada (NCIC) scale were used to assess the severity of diarrhea. Data were analyzed using paired t tests to test for differences in VAS and NCIC scores between baseline and 14 days. Pearson correlation was used to explore the relationships between change in diarrhea and patient baseline factors. At day 0, the mean VAS +/- standard deviation was 6.6 +/- 2.1 and decreased to 5.3 +/- 1.9 (p=.01) after 14 days. At day 0, the mean NCIC score was 1.9 +/- 0.8 and decreased to 1.2 +/- 0.9 (p=.005) after 14 days. No baseline patient factors predicted change in NCIC or VAS grade. Calcium carbonate is associated with a reduction of diarrhea in individuals with diarrhea induced by PI.