Topic overview

Start with the big picture

Plant-derived drugs include several distinct chemical groups with different sources and therapeutic roles. Examples include morphine and codeine from the opium poppy, cardiac glycosides from Digitalis species, and quinine and quinidine from Cinchona. Other examples illustrate how plant compounds can affect microtubules, muscarinic receptors, catecholamine storage, or inflammation. Learning these medicines involves more than matching a drug to a plant: it also means relating its mechanism to its clinical application and recognizing relevant cautions, such as narrow therapeutic windows or dose-limiting adverse effects. This preview introduces that source–mechanism–use approach; the full lesson develops it across a wider range of drug families.