Pharmacology

Introduction/Overview Methotrexate, a structural analogue of folic acid, represents a cornerstone therapeutic agent in both oncology and immunology. Originally developed as a chemotherapeutic drug in the 1940s, its application has expanded significantly to become a first-line disease-modifying antirheumatic drug (DMARD) for numerous autoimmune conditions. This evolution from a cytotoxic agent to an immunomodulator, dependent on … Read more

Introduction/Overview Colchicine is a naturally occurring alkaloid derived from plants of the genus Colchicum, most notably the autumn crocus (Colchicum autumnale). Its use as a therapeutic agent dates back to antiquity, with historical records describing its application for joint pain and swelling. In modern medicine, colchicine has secured a definitive role primarily in the management … Read more

Introduction/Overview Allopurinol represents a cornerstone therapeutic agent in the management of disorders characterized by hyperuricemia, most notably chronic gout. As a structural analog of the natural purine base hypoxanthine, it functions as a potent inhibitor of xanthine oxidase, the enzyme responsible for the terminal steps of uric acid biosynthesis. The clinical introduction of allopurinol in … Read more

1. Introduction/Overview Cetirizine is a widely prescribed second-generation antihistamine, recognized as a cornerstone in the management of allergic conditions. As a piperazine derivative and a carboxylated metabolite of hydroxyzine, it represents a significant advancement over first-generation agents due to its improved receptor selectivity and reduced penetration of the blood-brain barrier. The clinical importance of cetirizine … Read more

1. Introduction/Overview Diphenhydramine represents a prototypical and historically significant agent within the first-generation H1 receptor antagonist class of drugs. Initially synthesized in the 1940s, its introduction marked a pivotal advancement in the therapeutic management of allergic conditions. As an ethanolamine derivative, diphenhydramine possesses a molecular structure that confers not only potent antihistaminic activity but also … Read more

1. Introduction/Overview Histamine, chemically known as 2-(4-imidazolyl)ethylamine, is a biogenic amine with profound physiological and pathological roles. It functions as a critical mediator in immediate hypersensitivity reactions, gastric acid secretion, and neurotransmission within the central nervous system. The clinical relevance of understanding histamine pharmacology is paramount, as drugs modulating its actions—antihistamines—are among the most widely … Read more

1. Introduction/Overview Naloxone hydrochloride represents a critical pharmacotherapeutic agent within emergency medicine and toxicology. As a competitive opioid receptor antagonist, its primary clinical utility resides in the rapid reversal of life-threatening respiratory depression induced by opioid overdose. The escalating prevalence of opioid use disorders and the associated mortality from overdose have rendered naloxone an indispensable … Read more

1. Introduction/Overview Codeine, an alkaloid derived from the opium poppy Papaver somniferum, represents one of the most historically significant and widely utilized opioid medications. As a prototypical weak opioid agonist, it occupies a unique position in therapeutic arsenals for pain and cough management. Its clinical relevance stems from a perceived favorable balance between efficacy and … Read more

1. Introduction/Overview Pethidine, also known internationally as meperidine, is a synthetic opioid analgesic with a significant historical role in pain management. First synthesized in 1939, it represented one of the earliest fully synthetic opioids and was initially investigated for its anticholinergic properties before its potent analgesic effects were recognized. For decades, pethidine occupied a central … Read more