Hyponatremia
Sources
Hyponatremia
Clinical Summary
Persistent hyponatremia documented from 2026-01-28, in the context of AML treatment with Azacitidine + Venetoclax. Sodium has ranged from 128 to 135 mmol/L (reference range 136–145 mmol/L). Apr 20 absolute nadir: 128 mmol/L — moderate hyponatremia. Improved to 134 mmol/L (Apr 27) — mild hyponatremia, still below normal. Prior nadir was 129 mmol/L (2026-03-12). Consistently accompanied by hypochloremia (Cl 93–97 mmol/L). Concurrent worsening hypomagnesemia (Mg 1.2) is likely a pathophysiologic contributor.
Sodium Values Over Time
| Date | Sodium (mmol/L) | Chloride (mmol/L) | Flag | Context |
|---|---|---|---|---|
| 2026-01-28 | 135 | — | Low | First documented low value |
| 2026-02-03 | 133 | — | Low | During Aza-Ven cycle |
| 2026-02-19 | 131 | 96 (L) | Low | Accompanied by hypochloremia |
| 2026-03-02 | 132 | 97 (L) | Low | Persistent |
| 2026-03-12 | 129 | 94 (L) | Low | Nadir |
| 2026-03-22 | 133 | 98 (L) | Low | Slight recovery |
| 2026-04-06 | 132 | 93 (L) | Low | Stable low |
| 2026-04-13 | 133 | 94 (L) | Low | Stable low |
| 2026-04-20 | 128 | 93 (L) | Low — absolute nadir | Moderate hyponatremia |
| 2026-04-27 | 134 | 95 (L) | Low — improving | Mild hyponatremia; Mg concurrently 1.4 |
| 2026-05-04 | 142 | 103 (N) | NORMAL — resolved | First normal since Jan 2026; Mg 1.6 (N) |
Reference ranges: Sodium 136–145 mmol/L; Chloride 98–106 mmol/L.
[!success] RESOLVED — May 4, 2026
Na 142 mmol/L (first normal since onset Jan 28, 2026). Cl 103 mmol/L (normalized). Mg concurrently recovered to 1.6 (N). Duration of hyponatremia: ~97 days. Etiology presumed SIADH — workup (urine osm, urine Na, serum osm) never completed; this gap remains unresolved but clinically moot now. See Vaptan Assessment, Magnesium.
Clinical Context
Hyponatremia in the setting of AML treatment likely related to:
- Chemotherapy effects: Azacitidine and Venetoclax can both contribute to electrolyte disturbances
- SIADH: Syndrome of inappropriate antidiuretic hormone — a common cause of euvolemic hyponatremia in cancer patients
- Nutritional factors: Reduced oral intake during chemotherapy cycles
- Magnesium depletion: Oral Mg supplement lapsed ~2026-04-06 (patient ran out). Mg dropped to 1.2 (new low) on same date as Na nadir 128. Hypomagnesemia impairs ADH regulation and renal sodium handling. See Magnesium Oral.
- Volume status changes: Related to treatment cycles and supportive care
The hyponatremia has worsened to moderate (Na 128, Apr 20 2026). Euvolemic electrolyte pattern (low Na, low Cl, normal K, normal HCO3, normal Cr/BUN) is most consistent with SIADH. SIADH workup (urine Na, urine osmolality) has not been performed. See Non Hematology Labs Insights Apr2026 for integrated electrolyte analysis.
Related
- Sodium — longitudinal lab tracking
- Chloride — frequently low in conjunction
- Aml — underlying diagnosis; treatment context
Updated automatically during ingest.