
In this This Is Why with Dr. Busti pharmacology review, Dr. Busti explores the pharmacology, physiology, and clinical relevance of the H₂ receptor antagonists—a long-standing drug class that remains an important option for managing GERD, dyspepsia, and peptic ulcer disease. Drawing on decades of experience in clinical medicine and academia, he explains how agents like cimetidine, famotidine, and nizatidine work at the cellular level to reduce gastric acid secretion, and how understanding their mechanism, pharmacokinetics, and drug interactions helps clinicians use them safely and effectively.
From bedside use in GERD to adjunctive therapy in anaphylaxis and inpatient acid suppression, this episode connects the why behind H₂ blockers’ continued place in therapy — including when to switch to PPIs or potassium-competitive acid blockers (P-CABs).
Chapter Table of Contents
00:00 Introduction to H2 Receptor Antagonists (H2RA)
00:36 History of Cimetidine, Ranitidine, Famotidine & Nizatidine
01:07 Why H2RAs Still Matter: Clinical Relevance in Modern Practice
02:44 Indications & Therapeutic Uses: GERD, Ulcers, Dyspepsia & More
08:27 Anatomy & Pathophysiology: GERD, Ulcers, Barrett’s, GI Bleeding
16:09 Mechanism of Action: Blocking H2-Mediated Acid Secretion
20:27 OTC Antacids vs H2RAs: Onset, Duration & Clinical Positioning
25:04 Pharmacokinetics & Pharmacodynamics: Acid Suppression Duration, Metabolism & Clinical Impact
29:26 Drug Interactions: CYP Pathways, Binding, and Clinical Impact
30:33 Self-Treatment Pitfalls: Misdiagnosis, Heartburn vs ACS & When to Seek Care
31:52 Treatment Durations: OTC vs Prescription Use, GERD & Ulcer Healing Timelines
#H2blockers #pharmacology #GIpharmacology #medicaleducation
Disclaimer: This content is for educational purposes only and is not intended to provide medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have heard in this content.

H2 Receptor Antagonists Tables
H2 Receptor Antagonists Tables