💊 Medicinal Chemistry Notes: Antihistaminic Drugs (H1 & H2 Blockers)For B.Pharm / D.Pharm / M.Pharm Students – PharmaEasyNotes
📌 Introduction Antihistaminic drugs are medicines that block the action of histamine, a chemical released during allergic reactions. Histamine causes: 👉 Sneezing, itching, redness 👉 Swelling, watery eyes 👉 Increased gastric acid secretion To control these effects, antihistamines are used in allergy and acid-related disorders. 🧬 What is Histamine? Histamine is a biogenic amine stored in mast cells and basophils. It acts on receptors: H1 → Allergy symptoms H2 → Acid secretion H3, H4 → CNS & immune system (less common in syllabus) 👉 In medicinal chemistry, mainly H1 & H2 blockers are studied. 📊 Classification of Antihistaminic Drugs (Flowchart) Antihistaminic Drugs | -------------------------------- | | ...