threshold dose [AS, therscold + Gk, dosis, giving] , 1. a measure of a dose of radiation exposure defined in terms of conditions needed to produce a visible erythema in a given proportion of people exposed. Also called minimal erythema dose, skin erythema dose, threshold erythema dose. 2. the minimum dose of a drug needed to produce a measurable response. Administration of drugs at dosages of intervals that do not maintain concentration about the threshold level wastes the medication and, in cases such as antibiotic treatment or cancer chemotherapy, can have additional adverse consequences resulting from the selective growth of cancer cells or microorganisms that are more resistant to the medication.
