A radioimmunoassay for nortriptyline (and other tricyclic antidepressants) in plasma

Abstract

The radioimmunoassay for nortriptyline described here can detect as little as 1 μg/liter of plasma. Within-day precision and day-to-day precision (CV) were ±6 and ±11%, respectively, over the concentration range 100-200 μg/liter. The major metabolite hydroxy-nortriptyline, does not cross react with the antiserum. Results so obtained correlate closely with results by a double-isotope derivative dilution technique. The major advantages of this technique over currently available methods are its sensitivity, convenience (many samples can be processed in one day), simplicity, and cost. Further, prior extraction of plasma samples is not required. Cross-reactivity studies have been carried out with..