Review: Failure of current digoxin monitoring for toxicity: new monitoring recommendations to maintain therapeutic levels for efficacy.

The current recommendations for monitoring digoxin, a narrow therapeutic index drug, are limited to confirming medication use or investigating suspicion of toxicity and fail our oath to do no harm. Numerous meta-analyses evaluating digoxin use consistently recommend frequent monitoring to maintain the level of 0.5 to ≤1.0 ng/ml because higher levels lead to increased morbidity and mortality without benefit. Data from the United States National Poison Control Center (2012-2020) show annual deaths due to digoxin of 18-36 compared to lithium's 1-7, and warfarin's 0-2 respectively. The latter drugs also have narrow therapeutic indexes like digoxin yet are more carefully monitored. Recognition of digoxin toxicity is impaired as levels are not being routinely checked after medications are added to a patient's regimen. In addition, providers may be using ranges to guide treatment that are no longer appropriate. It is imperative that monitoring guidelines and laboratory therapeutic levels are revised to reduce morbidity and mortality due to digoxin. In this review, we provide a comprehensive literature review of digoxin monitoring guidelines, digoxin toxicity, and evidence to support revising the ranges for serum digoxin monitoring.

Hypothyroidism Complicated by Vitamin C and Thiamin Deficiency in Surgical Patients.

Multiple vitamin deficiencies together with endocrinopathy may be encountered in individuals presenting with critical illness. Following the surprise postmortem diagnosis of concomitant scurvy, Wernicke, and hypothyroidism in an elderly woman presenting with a mix of atypical symptoms, patients considered at risk were tested for TSH, vitamin C, and thiamin levels. Between September 1, 2018, and December 31, 2022, 801 vitamin C levels in 679 patients were measured in our rural hospital and 309 (39%) were found <0.4 mg/dL. In this population, 39% of 626 thiamin levels were found to be low. Twenty-two patients with vitamin C and/or thiamin deficiency and elevated TSH levels were identified. Two patients died from scurvy; one also had myxedema. The incidence of vitamin C and thiamin deficiency in our patient population was higher than expected. Further studies should determine if this is unique to our rural setting or part of a bigger trend associated with poor dietary choices.