Key Points
- Evaluate the role of quantitative serum and plasma assay techniques in optimizing cardiac glycoside therapy and characterizing digitalis clinical pharmacology and toxicity.
- Reviewed quantitative assay technics for digitoxin, digoxin, and ouabain, including radioimmunoassay, red cell rubidium-86 uptake inhibition, and ATPase enzymatic displacement.
- Analyzed clinical pharmacokinetic parameters across various physiological contexts, including cardiopulmonary bypass, gastrointestinal malabsorption, and drug-drug interactions.
- Mean circulating digoxin and digitoxin concentrations are significantly elevated in patients presenting with clinical toxicity compared to nontoxic control patients.
- Individual tolerance to digitalis levels decreases in the presence of hypokalemia, hypercalcemia, hypomagnesemia, acid-base disorders, hypothyroidism, and severe coronary artery disease.
- Radioimmunoassay evaluations established a 21-hour plasma half-life for ouabain, demonstrating that post-equilibrium serum concentrations correlate closely with the duration of pharmacologic effect.
Structured PICO
IInterventionQuantitative assay technics for digitalis (digoxin, digitoxin, ouabain)
Quantitative assay techniques for cardiac glycosides provide a valuable tool for understanding their clinical pharmacology and managing digitalis toxicity, provided individual patient factors are considered.