ABSTRACT
The radioimmunoassay of digoxin is one of the most important services of the nuclear medicine laboratory. Precision and accuracy in the performance of the test are especially critical. A number of commerical kits are available and reliable. Pitfalls to be avoided includelimited availability or delay in performance of the assay; failure to consider senitizing factors; drawing the blood sample too soon after a digoxin dose; failure to consider desensitizing factors; forgetting that renal function is a major determinant of blood and tissue digoxin levels; assuming patient compliance and uniform intestinal absorption (bioavailiability with all digoxin preparations in all patients; attempting to interpret digoxin levels without the necessary clinical information; and failure to deliver the result to the proper person. If one avoids these pitfalls, and important service will be rendered in the evaluation of the patient requiring digitalis therapy.