Introduction Methotrexate is a synthetic folate antagonist that has established roles in the treatment of malignant neoplasms and a variety of autoimmune disorders. Its mechanism of action is predicated upon competitive inhibition of dihydrofolate reductase (DHFR), thereby attenuating the synthesis of nucleotides required for DNA replication and cell proliferation. The therapeutic spectrum of methotrexate spans…
Introduction Colchicine is a naturally occurring alkaloid traditionally derived from the plant Colchicum autumnale. The compound has been employed for centuries in the treatment of inflammatory disorders, most notably gout and familial Mediterranean fever. Its therapeutic efficacy stems from its capacity to inhibit microtubule polymerization, thereby modulating leukocyte function and cytokine release. Modern pharmacology has…
Introduction Definition and Overview Allopurinol is a purine analog that functions primarily as a xanthine oxidase inhibitor. By competitively binding to the enzyme’s active site, it reduces the synthesis of uric acid from hypoxanthine and xanthine. The drug is widely employed to manage hyperuricemia in conditions such as gout, uric acid nephrolithiasis, and tumor lysis…
1. Introduction Definition and Overview Cetirizine is a second‑generation, selective inverse agonist of the histamine H1 receptor. It functions by blocking the binding of endogenous histamine, thereby mitigating the classic signs of allergic inflammation such as pruritus, rhinorrhea, and bronchoconstriction. The drug is administered orally and is available in both free base and salt (cetirizine…
Introduction Diphenhydramine is a first‑generation, non‑selective antihistamine that blocks histamine H1 receptors and exhibits significant anticholinergic activity. It is widely used for the treatment of allergic reactions, acute motion sickness, insomnia, and as a component of many combination analgesic preparations. The drug was first synthesized in the early 1940s and entered clinical use in the…
Introduction Definition and Overview Histamine is a biogenic amine synthesized from the amino acid histidine through the action of histidine decarboxylase. It functions as an endogenous mediator of numerous physiological processes, including neurotransmission, gastric acid secretion, vasodilation, and immune modulation. The molecule is stored primarily in mast cells and basophils and is released upon activation…
Introduction Naloxone is a competitive, high‑affinity antagonist of the μ‑opioid receptor, employed primarily to reverse respiratory depression induced by opioid overdose. The compound was first synthesized in the 1960s and introduced clinically in the early 1970s, rapidly becoming the cornerstone of emergency treatment for opioid toxicity. Its importance in pharmacology derives from its unique receptor…
Introduction Codeine is a naturally occurring alkaloid belonging to the opioid analgesic class. It functions primarily as a mild to moderate pain reliever and antitussive agent. The monograph is intended to provide a structured overview of codeine, encompassing its historical development, pharmacological profile, clinical applications, and safety considerations. The content is tailored to medical and…
Introduction Definition and Overview Paracetamol, also known as acetaminophen, is a widely used analgesic and antipyretic agent. It is classified as a non‑steroidal anti‑inflammatory drug (NSAID) in terms of its therapeutic indications, yet it lacks significant anti‑inflammatory activity. The drug is available in a variety of formulations, including tablets, capsules, suspensions, suppositories, and intravenous solutions,…
Introduction Monographs constitute an essential reference framework for the systematic study of pharmaceutical agents. The present monograph focuses on pethidine (also known as meperidine), a synthetic opioid analgesic that has maintained clinical relevance across diverse therapeutic settings. This overview delineates the chemical identity, pharmacological class, and principal clinical roles of pethidine, thereby furnishing a foundation…