The reason for discovering a new drug is to replace a less-effective drug.
What is a drug?
- "It is a chemical substance, which, when administered to a living organism, produces a biological effect."
- Some of the drugs include: anti-depressant, CNS stimulants, analgesics, etc.
Why some drugs become less-effective?
- As we use the drug for long time it creates a tolerance level, where our body fails to produce a response when administered by such drugs.
- Over the time, diseases undergo various types of mutation and cannot be treated by using the same drug that was used before. So, a new drugs are being discovered from time to time.
Hence, the correct option is B. To replace a less-affective drug.
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