When to Discontinue Sodium Bicarbonate in Outpatient CKD
Discontinue sodium bicarbonate when serum bicarbonate consistently reaches ≥22 mmol/L, when adverse effects occur (edema, hypertension, gastrointestinal intolerance), or when kidney replacement therapy is initiated. 1, 2
Target Bicarbonate Levels for Discontinuation
The primary indication for stopping sodium bicarbonate is achieving and maintaining adequate serum bicarbonate correction:
- Discontinue when serum bicarbonate reaches ≥22 mmol/L on consecutive measurements 1, 2
- The KDIGO 2024 guidelines recommend considering pharmacological treatment to prevent bicarbonate levels from falling below 18 mmol/L, implying that therapy should maintain levels above this threshold 1
- Once bicarbonate normalizes (typically ≥22 mmol/L), continued supplementation is unnecessary and may cause metabolic alkalosis 2, 3
Safety-Related Discontinuation Criteria
Stop sodium bicarbonate immediately if any of the following develop:
- Worsening edema or fluid overload that cannot be managed with diuretic adjustment 2, 4
- Uncontrolled hypertension despite optimization of antihypertensive medications 4
- Gastrointestinal adverse effects including severe nausea, vomiting, or abdominal distension requiring medication discontinuation 3
- Symptomatic metabolic alkalosis (pH >7.45 with symptoms) 5
Studies show that 17.7% of patients discontinue sodium bicarbonate due to adverse events, significantly higher than alternative alkali therapies 3. The most common reasons include gastrointestinal intolerance and edema 3, 5.
Clinical Context for Discontinuation
Consider discontinuation in these specific scenarios:
- Initiation of kidney replacement therapy (dialysis): Patients on maintenance dialysis receive bicarbonate loading during sessions, making oral supplementation unnecessary and potentially harmful due to post-dialysis metabolic alkalosis 5
- Sodium-restricted diet requirements: Patients requiring strict sodium restriction (<2g/day) for heart failure or severe hypertension should discontinue sodium bicarbonate unless no alternative exists 6
- Achievement of stable kidney function: In patients where metabolic acidosis has resolved and eGFR has stabilized for >6 months with bicarbonate levels consistently ≥22 mmol/L 2, 7
Monitoring Strategy Before Discontinuation
Before stopping sodium bicarbonate, verify:
- Serum bicarbonate ≥22 mmol/L on at least two measurements 2-4 weeks apart 1, 2
- Stable kidney function (eGFR not declining >3 mL/min/1.73m² per year) 7
- No ongoing acidosis-generating conditions (diarrhea, proximal RTA, high protein intake) 5
After discontinuation, recheck serum bicarbonate in 4-6 weeks to ensure levels remain stable 1, 2. If bicarbonate falls below 20 mmol/L, consider restarting therapy 1.
Important Caveats
Do not discontinue sodium bicarbonate based solely on:
- eGFR decline alone: The UBI study demonstrated that sodium bicarbonate treatment reduces creatinine doubling and delays dialysis initiation in CKD stages 3-5, so declining eGFR is actually an indication to continue, not stop 7
- Mild blood pressure elevation: Studies show sodium bicarbonate does not significantly increase 24-hour ambulatory blood pressure in most CKD patients, so mild BP changes should prompt antihypertensive adjustment rather than bicarbonate discontinuation 4
- Duration of therapy: Unlike the FDA labeling for over-the-counter use (maximum 2 weeks), prescription sodium bicarbonate for CKD-related metabolic acidosis can be continued long-term as medically indicated 6, 7
The maximum safe dose is <4 grams per 24 hours from all sources to minimize adverse effects, but this applies to acute over-the-counter use rather than chronic prescription therapy for CKD 6.