Scott Fitter, BCCCP, PharmD
Clinical Pharmacist
Loma Linda University Medical Center
Loma Linda, California
Disclosure information not submitted.
Ashley Tuttle, PharmD
Pharmacist
Loma Linda University Medical Center, United States
Disclosure information not submitted.
Henry Hua, MS, PhD
Assistant Professor
Marshall B. Ketchum University- College of Pharmacy, United States
Disclosure information not submitted.
Kayvan Moussavi, BCCCP, PharmD
Assistant Professor
Marshall B. Ketchum University- College of Pharmacy
Fullerton, California, United States
Disclosure information not submitted.
Title: Effects of Concurrent Magnesium Supplementation during Treatment of Hypokalemia in the ED
Introduction: Hypokalemia is a common disorder with clinical manifestations that may include muscle weakness, neurological disturbances, and cardiac dysrhythmias. Concomitant magnesium supplementation is frequently recommended despite limited evidence to support its use. The purpose of this study was to determine the clinical effects of magnesium supplementation in patients being treated for hypokalemia in the emergency department (ED).
Methods: This IRB approved, single center, retrospective chart review evaluated adults treated with intravenous (IV) potassium for hypokalemia (serum potassium < 3.5 mMol/L) in the ED between 7/1/2016 and 6/30/2020. Patients given magnesium supplementation within 4 hours of potassium administration (MG+) were compared to those not given concurrent magnesium (MG-). Patients that were pregnant, prisoners, or receiving oral potassium or magnesium prior to ED presentation were excluded. The primary outcome was time to potassium normalization (≥3.5 mMol/L). Secondary outcomes included change in serum potassium after treatment, incidence of potassium normalization within 24 hours of treatment, incidence of adverse effects related to potassium or magnesium administration, intensive care unit (ICU) length of stay (LOS), hospital LOS, and in-hospital mortality.
Results: Two hundred patients were included in this study (MG+ = 100; MG- = 100). Patients in the MG- group more frequently had history of myocardial infarction (16% vs. 6%; p=0.02) and alcoholism (16% vs. 6%; p=0.02). Patients in the MG+ group had higher incidence of symptomatic hypokalemia (34% vs. 19%; p=0.02), lower initial serum potassium (2.8 [2.6-3] vs. 3 [2.8-3.2] mMol/L; p=0.002) and higher incidence of severe hypokalemia (15% vs. 8%; p=0.03). There were no differences in time to serum potassium normalization, change in serum potassium after treatment, incidence of potassium normalization within 24 hours, ICU LOS, hospital LOS, or mortality. Hypermagnesemia occurred more frequently in MG+ patients (7% vs. 1%; p=0.03).
Conclusions: Magnesium supplementation during treatment of hypokalemia with IV potassium was not associated with a decrease in the time to serum potassium normalization. However, use was associated with an increased incidence of hypermagnesemia. Additional studies to confirm these findings are warranted.