Drug Discovery and Development

This lesson covers how new drugs are discovered, developed, and tested before they can be used by patients. You need to understand the stages of drug development, the importance of clinical trials, and the concepts of efficacy, toxicity, and dosage. The development of new medicines is a long, expensive, and rigorous process designed to ensure patient safety.

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Where Do Drugs Come From?

Historically, many drugs were extracted from plants and microorganisms. Modern drugs may be discovered from natural sources or designed in laboratories.

Source	Example Drug	Original Use / Source
Plants	Aspirin	Extracted from willow bark — used for centuries as a painkiller
Plants	Digitalis	Extracted from foxgloves — used to treat heart conditions
Microorganisms	Penicillin	Produced by the Penicillium mould — the first antibiotic
Synthetic (laboratory)	Many modern drugs	Designed using computer modelling and chemistry
Plants	Quinine	Extracted from cinchona tree bark — used to treat malaria

Traditional Medicine