divided dose

dose (dōs) the quantity to be administered at one time, as a specified amount of medication or a given quantity of radiation.

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absorbed dose  that amount of energy from ionizing radiations absorbed per unit mass of matter, expressed in rads.

air dose  see under exposure.

booster dose  a dose of an active immunizing agent, usually smaller than the initial dose, given to maintain immunity.

divided dose  fractionated d.

effective dose  (ED) that quantity of a drug that will produce the effects for which it is given.

erythema dose  the amount of radiation which, when applied to the skin, causes temporary reddening.

fatal dose  lethal d.

fractionated dose  a fraction of the total quantity of a prescribed drug or radiation to be given at intervals.

infective dose  that amount of pathogenic organisms that will cause infection in susceptible subjects.

infinitesimal dose  see under principle.

lethal dose  that quantity of an agent that will or may be sufficient to cause death.

maximum dose  the largest dose consistent with safety.

maximum permissible dose  (MPD) the largest amount of ionizing radiation that one may safely receive in a specified period according to recommended limits in radiation protection guides.

median curative dose  (CD50) a dose that abolishes symptoms in 50 per cent of test subjects.

median effective dose  (ED50) a dose that produces the desired effect in 50 per cent of a population.

median immunizing dose  the dose of vaccine or antigen sufficient to provide immunity in 50 per cent of test subjects.

median infective dose  (ID50) the amount of pathogenic microorganisms that will cause infection in 50 per cent of the test subjects.

median lethal dose  (LD50) the quantity of an agent that will kill 50 per cent of the test subjects; in radiology, the amount of radiation that will kill, within a specified period, 50 per cent of individuals in a large group or population.

median toxic dose  (TD50) the dose that produces a toxic effect in 50 per cent of the population.

minimum dose  the smallest dose that will produce an appreciable effect.

minimum lethal dose  (MLD)

1. the smallest amount of toxin that will kill an experimental animal.

2. the smallest quantity of diphtheria toxin that will kill a guinea pig of 250 g weight in 4 to 5 days when injected subcutaneously.

skin dose  (SD)

1. the air dose of radiation at the skin surface, comprising primary radiation plus backscatter.

2. the absorbed dose in the skin.

threshold dose  the minimum dose of ionizing radiation, a chemical, or a drug that will produce a detectable degree of any given effect.

threshold erythema dose  the single skin dose that will produce in 80 per cent of those tested a faint but definite erythema within 30 days, and in the other 20 per cent, no visible reaction. Abbreviated T.E.D.

tolerance dose  the largest quantity of an agent that may be administered without harm.

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divided dose,

a measured fraction of a full dose of a medication, given at short intervals so that the full dose is eventually taken within a specified period.

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dose

the quantity to be administered at one time, as a specified amount of medication or a given quantity of radiation.

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absorbed dose

that amount of energy from ionizing radiations absorbed per unit mass of matter, expressed in Grays.

air dose

the intensity of an x- or gamma-ray beam in air, expressed in coulombs per kilogram.

booster dose

an amount of immunogen (vaccine, toxoid or other antigen preparation), sometimes smaller than the original amount, injected at an appropriate interval after primary immunization to enhance and sustain the immune response to that immunogen.

curative dose (CD)

a dose that is sufficient to restore normal health.

divided dose

a fraction of the total quantity of a drug prescribed to be given at intervals, usually during a 24-hour period.

dose equivalent limits

the limits of ionizing radiation set for radiation workers and the general public by the International Commission on Radiological Protection. For radiology workers this limit for the whole body is 50 mSv.

fatal dose

lethal dose.

dose fractions

in radiation therapy, the small doses given to reach the total radiation dose during the treatment period.

infectious dose 50 (ID₅₀)

that amount of pathogenic microorganisms that will produce infection in 50% of the test subjects.

infective dose (ID)

that amount of pathogenic microorganisms that will cause infection in susceptible subjects.

lethal dose (LD)

the amount of toxin or drug that will kill an animal.

dose level

the amount administered per unit of body weight.

loading dose

the initial large dose of a drug given to bring tissue and fluid levels to an effective concentration quickly. Called also priming dose.

maintenance dose

the smaller doses given to maintain effective levels in body fluids and tissues after the loading dose has achieved the concentration desired.

maximum permissible dose

see dose equivalent limits (above).

median curative dose (CD₅₀)

a dose that abolishes signs in 50% of test animals.

median effective dose (MED)

the dose that produces the desired effect in 50% of the test animals.

median lethal dose (MD₅₀)

the quantity of an agent that will kill 50% of the test subjects; in radiology, the amount of radiation that will kill, within a specified period, 50% of individuals in a large group or population.

minimum lethal dose (MLD)

the lowest dose which kills all of the test subjects.

dose rate

the amount administered per unit of time.

dose response

1. the incremental change in the subject per unit of additional dose. The response as a function of the dose.

2. the frequency of occurrence of a disease as the intake of the suspected risk factor increases. The relationship is expressed by the proximity of the illustrative curve to the expected relationship.

skin dose

1. the air dose of radiation at the skin surface, comprising the primary radiation plus backscatter.

2. the absorbed dose in the skin.

tolerance dose

the largest quantity of an agent that may be administered without harm.