Does Phoslo (calcium acetate) cause diarrhea in patients with End-Stage Renal Disease (ESRD)?

Phoslo (Calcium Acetate) and Diarrhea in ESRD Patients

Calcium acetate (Phoslo) can cause diarrhea in ESRD patients, though it is not among its most common side effects. While the available evidence specifically addressing diarrhea with Phoslo in ESRD patients is limited, we can draw conclusions from related evidence.

Gastrointestinal Side Effects of Calcium Acetate

• Calcium-based phosphate binders like Phoslo can cause gastrointestinal side effects, though they are generally less frequent than with other medications used in ESRD patients 1
• Diarrhea has been reported as a potential side effect of calcium acetate, though it occurs less frequently than other GI symptoms such as mild nausea 2, 3
• When comparing different phosphate binders, calcium acetate appears to have a more favorable GI side effect profile than some alternatives 4

Factors Affecting GI Tolerance in ESRD Patients

• Timing of administration is important - calcium acetate is most effective when given with meals, which may also improve GI tolerance 2
• The dose of calcium acetate may influence the likelihood of GI side effects - higher doses may increase the risk of diarrhea 5
• ESRD patients often have multiple comorbidities and take numerous medications that can contribute to diarrhea, making it difficult to attribute this symptom solely to calcium acetate 6

Management Strategies for ESRD Patients with GI Symptoms

• If diarrhea occurs with calcium acetate, consider:

  • Dividing the total daily dose into smaller, more frequent doses 5
  • Ensuring administration with meals rather than on an empty stomach 2
  • Temporarily reducing the dose and gradually titrating up as tolerated 4

• For persistent diarrhea despite optimization:

  • Consider alternative phosphate binders such as sevelamer, which may have different side effect profiles 1, 4
  • Evaluate for other causes of diarrhea in ESRD patients, as multiple factors can contribute to this symptom 6

Comparative Side Effect Profiles

• When comparing medications commonly used in ESRD patients, cinacalcet has been associated with a higher risk of diarrhea (RR 1.15) compared to placebo 6
• Calcium acetate generally has fewer GI side effects than some other medications used in ESRD management 1, 4
• Unlike some medications that require significant dose adjustments in ESRD (such as certain antibiotics or antidepressants), calcium acetate's dosing is primarily determined by phosphorus levels rather than renal function 7, 8

Clinical Perspective

• The benefits of controlling phosphate levels with calcium acetate in ESRD patients generally outweigh the risk of diarrhea for most patients 1, 5
• If diarrhea occurs and persists despite optimization strategies, alternative phosphate binders should be considered 4
• Non-calcium-based binders may be preferred in specific situations (e.g., hypercalcemia), but they have their own side effect profiles to consider 4

While diarrhea can occur with calcium acetate use in ESRD patients, proper administration with meals and appropriate dose titration can minimize this side effect in most patients.