Abstract: PO2175
Selinexor-Associated Hyponatremia: Single-Center Real-World Data
Session Information
- Onco-Nephrology - 1
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Onco-Nephrology
- 1500 Onco-Nephrology
Authors
- Mamlouk, Omar, University of Texas MD Anderson Cancer Center, Houston, Texas, United States
- Jhaveri, Kenar D., Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States
- Kala, Jaya, University of Texas John P and Katherine G McGovern Medical School, Houston, Texas, United States
Background
Introduction: Hyponatremia is a commonly reported side effect in recent clinical trials evaluating the efficacy and safety of selinexor in treatment of refractory multiple myeloma (MM). With incidence ranging 7-47%. the hyponatremia was reported to be generally asymptomatic, transient, and highly responsive to medication dose reduction and sodium. The etiology for hyponatremia is not yet completely understood and speculated to be multifactorial, hypovolemia, diarrhea, poor solute intake, or pseudohyponatremia from high M protein level.
Methods
We retrospectively reviewed the medical records of all relapsed MM patients at our cancer institute. The study was approved by the institutional review board. We reviewed data relevant to hyponatremia in patients’ clinical presentation, medication history, comorbid conditions, physical examination, and laboratory review.
Results
Hyponatremia was seen in 13/17 patients within 5 weeks of therapy, 8 of whom required hospitalization. Three of these hospitalized patients had grade 3 hyponatremia (serum sodium 120 to ≤130 meq/l) with severe symptoms including fall and altered mental status. Both groups of patients received antiemetics, anti-depressants and diuretics that included thiazides. Cancer related pain was observed in both groups but the hyponatremic group was on higher dose selinexor and more likely to have more gastrointestinal side effects, sepsis, hypotension. Nephrology was consulted on only 4 out of 13 patients. These were the only patients with serological and urine studies done high urine osmolarity and high urine sodium concentration that along with euvolemia favored SIAD diagnosis in 3 out these 4 patients.
Conclusion
Our observations suggest that hyponatremia is multifactorial, as the patient`s co-morbidities, medications, and selinexor side effects (hypovolemia, nausea and possible unidentified factor) may contribute to hyponatremia. It is possibly dose dependent, more likely to occur with patients who had gastro-intestinal side effects, sepsis and hypotension. We recommend discontinuation of medications associated with hyponatremia prior to starting/during selinexor therapy, obtaining basic hyponatremia investigations, and early referral to nephrology to prevent potential serious symptoms