This patient is most likely experiencing digoxin toxicity. Common symptoms of this problem include nausea, vomiting, decreased appetite, fatigue, weakness, visual changes, and severe cardiac arrhythmias in severe cases (Pincus, 2016). Elliot is complaining of more than one of these symptoms simultaneously, and considering the possible interactions between digoxin, lisinopril, and amlodipine, digoxin toxicity is the most likely explanation for this presentation. Digoxin inhibits the Na-K-ATPase membrane pump leading to an increased intracellular sodium concentration. High intracellular sodium concentrations stimulate sodium-calcium exchange, leading to an increased intracellular calcium concentration as well. This allows for greater activation
