A dose-ranging study is a

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...

where different doses of an

agent Agent may refer to: Espionage, investigation, and law *, spies or intelligence officers * Law of agency, laws involving a person authorized to act on behalf of another ** Agent of record, a person with a contractual agreement with an insuran ...

(e.g. a

drug A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...

) are tested against each other to establish which dose works best and/or is least harmful. Dose-ranging is usually a pre-clinical, phase I or early phase II clinical trial. Typically a dose ranging study will include a

placebo A placebo ( ) can be roughly defined as a sham medical treatment. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures. Placebos are used in randomized clinical trials ...

group of subjects, and a few groups that receive different doses of the test drug. For instance, a typical dose-ranging study may include four groups: a placebo group, low-dose group, medium-dose group and a high-dose group. The maximum tolerable dose (MTD) information is necessary to be able to design such groups and therefore dose-ranging studies are usually designed after the availability of MTD information. The main goal of a dose-ranging study is to estimate the response vs. dose given, so as to analyze the

efficacy Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as '' effectiveness'', and it has often been used synonymously, although in pharmacology a distinction is now often made betwee ...

and

safety Safety is the state of being protected from harm or other danger. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk. Meanings The word 'safety' entered the English language in the 1 ...

of the drug. Although such a response will nevertheless be available from phase III or phase IV trials, it is important to carry out dose-ranging studies in the earlier phase I or phase II stages. There are advantages to using healthy volunteers. They are in a steady-state condition showing no different stages of disease and no variation due to disease. In addition, it is easy to recruit and select volunteers among varying age, sex, race etc. under identical conditions in which the test can be repeated. The main reasons for this is to avoid trials in the later phases using doses that are significantly different from those that will subsequently be recommended for clinical use and also to avoid the need for modification of dosing schedules at later stages where a large amount of data has already been accumulated for a different dose range. The duration of action should be determined during dose-ranging study, as it will allow definition of the dosage schedule. Because it is hard to measure reliable pharmacodynamic parameter, it is difficult to determine the duration of action during early clinical trials. Other parameters instead are suggested as a tentative dosage, such as half-lives in plasma and urine in various test species and human, receptor binding in vitro, or pharmacodynamic data in vivo in animals.

References

{{reflist Clinical trials