The Renaissance to Early Modern Era (16th to 18th Century)

Paracelsus (1493–1541):

• Paracelsus, a Swiss physician and alchemist, revolutionized the study of pharmacology by emphasizing the chemical basis of medicine. He was one of the first to argue that diseases were caused by specific external agents (e.g., bacteria, toxins) rather than imbalances in the body’s humors.
• Paracelsus introduced the concept of dose-dependent effects of drugs, famously stating that “the dose makes the poison”, highlighting that even beneficial substances could be toxic at high doses.
• He pioneered the use of chemical treatments over traditional herbal medicine, especially the use of minerals like mercury and arsenic for medicinal purposes.

Advances in Chemistry and Drug Discovery:

• During the Renaissance, the field of alchemy gave rise to modern chemistry, which greatly influenced the development of pharmacology. By the 17th and 18th centuries, chemists began isolating active ingredients from plants and minerals, such as morphine from opium (1803).
• William Cruickshank, an English chemist, isolated quinine from cinchona bark in 1820, a discovery that was crucial in the treatment of malaria.