dose response

dose response

a range of doses over which response occurs. Doses lower than the threshold produce no response while those in excess of the threshold exert no additional response. The shape of the curve is usually hyperbolic when plotted with linear axes and gives a sigmoidal curve when response is plotted versus the log of the dose. Beneficial drug responses are typically plotted on separate dose response curves. Because the dose response and the chemotherapeutic index can overlap to some degree and may have different slopes, the margin of safety is often considered to be a better index.

dose response

1. The relationship between the quantity or intensity of a treatment regimen and its effect on living cells, tissues, or organisms.

2. The relationship between the intensity of an exposure, e.g., to an infectious pathogen, physical stressor, or a toxin, and its effect on living organisms.

See also: response

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.