[Pharmacological aspects of digoxin complex formation with calcium and magnesium cations]

NMR spectroscopy was used to establish the formation of digoxin and digitoxin complexes with calcium ions. Microcolorimetric titration demonstrated the formation of two types of digoxin complexes with magnesium at a ratio of 1:1 and 1:2. It was noticed in rat experiments that digoxin (2.5 mg/kg) raises the magnesium level in liver tissue, whereas in a toxic dose of 12.5 mg/kg it increases the calcium content in the heart muscle.