Adverse drug reactions therapeutic index

Certainly, most in vitro assays cannot predict (a) metabolite effects, (b) adverse effects associated by accumulation, and (c) drug actions at targets with mutations. Nevertheless, early safety-profiling assays have the power to detect trends toward certain adverse reactions and organ toxicity and to navigate drug discovery teams away from them. The major difficulty is estimating the impact of the data on the clinical performance determined by the human therapeutic index. 

Phenazone, commonly known as antipyrine, is still used therapeutically in some countries, although it is now used mainly as a marker of hepatic enzyme drug metabolizing activity. It is an old compound with little recent investigation, usually taken in combination with other analgesics, and an exact analysis of its adverse effects is impossible. Phenazone seems to have a low toxicity index, in correspondence with its weak anti-inflammatory effect. Allergic reactions are very rare (SEDA-6, 92) (SEDA-14, 92) (SEDA-16,108), but subjects undergoing the phenazone test should be informed of the potential risk. 

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