You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is LD50 /ED50 is - and explain in detail?
Ans. is 'a' i.e.. Therapeutic index Therapeutic index o Drugs usually have more than one action. o The maximal response for the different action of a drug may be different ie the DRCs (Dose response curves) for different effects of a drug may be different. o The extent of separation of DRCs of a drug for different effects is a measure of its selectivity, e.g. the DRCs for bronchodilatation and cardiac stimulation are quite similar in case of isoprenaline but far apart in case of salbutamol - the latter is more selective. o The gap between the therapeutic effect DRC and the adverse effect DRC defines the safety margin or the therapeutic index. o In Experimental animals Therapeutic index = Median lethal dose (Ld50) ------------ Median effective dose (Ed50) o But in clinical set up, the therapeutic range is bounded by the dose w hich produces minimal therapeutic effect and the dose which produces maximal acceptable adverse effect. "Therapeutic index is the ratio between the toxic dose and the therapeutic dose of a drug, and is used as a measure of the relative safety of the drug for a particular treatment "