Dosage response relationship

It is interesting, as noted by Clark,2 that the dosage-response relationships when intact animals are used appear simpler than when specific tissues, such as the epidermis, are used as test objects. He suggests that this simplicity is apparent rather than real because, in... 

In most cases legislation and subsequent regulations will determine the ambient concentrations of pollutant to which the receptor is limited. Air quality criteria delineate the effects of air pollution and are scientifically determined dosage-response relationships. The relationships specify the reaction of the receptor or the effects when the receptor is exposed to a particular level of concentration for varying periods of time. Air quality standards are based on air quahty criteria and set forth the concentration for a given averaging time. Thus, the objective for a calculation is to determine if an entission will result in ambient concentrations that meet air quality standards. 

FIGURE 5.8. Examples of probit-log dosage response curves illustrating differences in slope curves and the relationship between the slope, LD50, and LD0i. 

LSD, relatively little systematic testing of performance over a range of LSD dosage and throughout the duration of its action had been reported. We therefore undertook studies that would reveal the dose-response relationship with more precision, initially by the oral route and later by intravenous or inhalation routes of administration. A total of approximately 100 subjects were tested between 1961 and 1966, at... 

Dose-response relationship A description of changes in effect (response) of an organism due to differing levels of exposure (dose) to a stressor such as a chemical or dosages of a drug. 

One principle that is central to the understanding of toxicology is the dose-response relationship, which implies that there is a threshold level below which no toxic effects are observed. This level can be approximated in studies in which animals are dosed with the pesticide the maximum dose tested at which there are no detectable differences between treated and untreated control animals is called the no observed effect level (NOEL). The dosage slightly in excess of the NOEL at which toxic effects are observed is referred to as the lowest observed effect level (LOEL). These two dosages should be relatively close together in order to clearly define the threshold level. 

Antimalarials are approved for rheumatoid arthritis, but they are not considered very efficacious DMARDs. Dose-response and serum concentration-response relationships have been documented for hydroxychloroquine. While antimalarials improve symptoms, there is no evidence that these compounds alter bony damage in rheumatoid arthritis at their usual dosages (up to 6.4 mg/kg/d hydroxychloroquine or 200 mg/d chloroquine). It usually takes 3-6 months to obtain a response. Antimalarials are often used for the treatment of the skin manifestations, serositis, and joint pains of... 

Drugs—Dose-response relationship. 2. Drugs—Dosage. 3. Oral medication. 4. Drug development. I. Zheng, Jack. 

US FDA Guidance for Industry (1997) Extended Release Oral Dosage Forms Development, Evaluation, and Application of In Vitro/In Vivo Correlations. September 1997 US FDA Guidance for Industry Exposure-Response Relationships - Study Design, Data Analysis, and Regulatory Applications. April 2003... 

BELLE founders noted that risks at low levels are estimated by various means, frequently utilizing assumptions about which there may be considerable uncertainty. BELLE is committed to the enhanced understanding of low-dose responses of all types, whether of an expected nature (e.g., linear, sublinear) or of a so-called paradoxical nature. Paradoxical dose-response relationships might include U-shaped dose-response curves and biphasic dose-response curves. The focus of BELLE now encompasses dose-response relationships to toxic agents, pharmaceuticals, and natural products over wide dosage ranges in in vitro and in vivo systems, including human populations. 

See also Dose-Response Relationship Food and Drug Administration, US Investigative New Drug Application LD50/LC50 (Lethal Dosage 50/Lethal Concentration 50) Pharmacokinetics/Toxicokinetics Redbook. 

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