Kayexalate Dosing Calculator
Note: This calculator provides estimated dosing recommendations for Kayexalate. Always consult with a healthcare provider for definitive treatment decisions. Typical dosing ranges:
- Oral: 15-60 g daily in divided doses (1-4 times daily)
- Rectal: 30-50 g every 6 hours as needed
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- Brand Name: Kayexalate
- Generic Name: Sodium Polystyrene Sulfonate
- Dosage Form: Powder
Kayexalate Dosage Guide Based on Serum Potassium Levels
Here is a general guideline comparing serum potassium levels and typical sodium polystyrene sulfonate dosages, as used in clinical settings:
| Serum Potassium (mEq/L) | Typical Dose | Route |
| 5.1 – 5.4 | Usually not required | — |
| 5.5 – 5.9 | 15 grams | Oral |
| 6.0 – 6.4 | 30 grams | Oral or Rectal |
| 6.5 – 6.9 | 45 grams | Oral or Rectal |
| ≥ 7.0 | 30–60 grams | Rectal preferred |
Dosing and Calculation
The dosage calculation is based on serum potassium levels and patient weight, with adjustments for the route of administration (oral vs. rectal). Here’s how it works:
1. Determine Hyperkalemia Severity
First, the calculator classifies the patient’s potassium level:
- Mild hyperkalemia: K⁺ <5.5 mEq/L
- Moderate hyperkalemia: K⁺ 5.5–6.4 mEq/L
- Severe hyperkalemia: K⁺ ≥6.5 mEq/L
2. Weight-Based Dosing (Oral Route)
For oral administration, Kayexalate dosing is weight-based (g/kg/day), with maximum daily limits:
| Potassium Level | Dosing Guidelines | Example Calculation (70 kg Patient) |
|---|---|---|
| Severe (≥6.5 mEq/L) | 1–1.5 g/kg/day (max 60 g/day) | 70 kg × 1.2 g/kg = **84 g/day → Capped at 60 g/day** (15 g every 6 hrs) |
| Moderate (5.5–6.4 mEq/L) | 0.5–1 g/kg/day (max 40 g/day) | 70 kg × 0.8 g/kg = **56 g/day → Capped at 40 g/day** (10 g every 6 hrs) |
| Mild (<5.5 mEq/L) | 0.3 g/kg/day (max 15 g/day) | 70 kg × 0.3 g/kg = **21 g/day → Capped at 15 g/day** (single daily dose) |
3. Fixed Dosing (Rectal Route)
For rectal administration, fixed doses are used (not weight-based):| Potassium Level | Dosing Guidelines | Total Daily Dose |
|---|---|---|
| Severe (≥6.5 mEq/L) | 50 g every 6 hrs | 200 g/day |
| Moderate (5.5–6.4 mEq/L) | 40 g every 6 hrs | 160 g/day |
| Mild (<5.5 mEq/L) | 30 g every 6 hrs (PRN) | 120 g/day (if needed) |
Important Clinical Notes:
- Onset: Oral Kayexalate starts working in ~1–2 hours; rectal works faster.
- Monitoring: Serum potassium levels must be monitored every few hours in severe cases.
- Maximum daily dose: Typically 60–90 grams/day, but can vary.
- Black Box Warning: Risk of intestinal necrosis, especially when used with sorbitol or in patients with GI issues.