Drugs efficacy

The drug has a broad dose range but efficacy in most instances may not be apparent until doses of 400 mg have been reached. An unusually large number of participants drop out because of lack of drug efficacy in some of the major trials (Arvanitis and Miller, 1997). 

Drug Efficacy Study A Report to the Commissioner of Food and Drugs, National Academy of Sciences, National Research Council, Washington, DC, 1969. 

Because of the power of the placebo effect, almost anything that is believed in seems to work for some types of medical problems. That is why the late Arthur K. Shapiro described the history of medicine as largely the history of the placebo effect.4 It is also why clinical experience alone cannot tell us whether a particular physical substance is an effective treatment. Placebo-controlled trials are required to demonstrate drug efficacy before drugs are approved for marketing. 

Drug efficacy is directly related to its intracellular concentration level, so it is necessary to evaluate the MTX concentration in cells. In particular, MTX is a folate antagonist, thus it binds to dihydrofolate reductase in competition with folate [71-77]. A low intracellular level of MTX caused by high efflux and low uptake in resistant cells is also the main disadvantage of MTX medication [78,79]. This leads to a high dosage of MTX for cancer treatment, which is also directly associated with adverse effects. 

MTX interferes with the growth of cancer cells by inhibiting the metabolism of folic acid. Drug efficacy was evaluated in vitro by MTT assay, as described above, and by Trypan Blue exclusion. Trypan Blue is a non-vital dye excluded by viable cells, but selectively staining dead cells. According to Figure 13.7, higher suppression of cell... 

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