Introduction Opiates are a class of drugs derived from opium that produce potent analgesic effects. They act primarily on opioid receptors in the central and peripheral nervous system to relieve pain, produce sedation, and induce euphoria. Common examples include morphine, codeine, and heroin. Opiates are widely used for moderate to severe pain but are associated … Read more
Introduction Noradrenaline (norepinephrine) is an endogenous catecholamine that functions as both a neurotransmitter and a hormone. It is widely used clinically as a vasopressor in conditions such as septic shock and acute hypotension. Noradrenaline primarily acts on α-adrenergic receptors with additional β1 receptor activity, leading to potent vasoconstriction and increased blood pressure. Mechanism of Action … Read more
Introduction Sodium nitroprusside is a potent, rapid-acting vasodilator used primarily in hypertensive emergencies and acute heart failure. It produces both arterial and venous dilation, leading to a significant reduction in blood pressure. Due to its immediate onset and short duration of action, it is administered intravenously under close monitoring. Mechanism of Action (Step-wise) A key … Read more
Introduction Nitrous oxide is an inhalational anesthetic gas with analgesic and sedative properties. It is widely used in anesthesia practice and procedural sedation, especially for short procedures. It has a rapid onset and recovery due to low blood solubility. Nitrous oxide provides good analgesia but relatively weak anesthetic potency, so it is often used in … Read more
Introduction Nitroglycerin is an organic nitrate widely used in the management of angina pectoris and acute coronary syndromes. It acts as a potent vasodilator, primarily affecting venous capacitance vessels, thereby reducing cardiac workload. It also improves coronary blood flow and relieves ischemic chest pain. Nitroglycerin is considered a cornerstone drug for rapid relief of angina. … Read more
Introduction Nitrofurantoin is a nitrofuran antibacterial drug used mainly for uncomplicated lower urinary tract infections. It is especially useful because it achieves therapeutic antibacterial activity in urine and acts through multiple intracellular targets within bacteria. Unlike many antibiotics that inhibit a single enzyme or pathway, nitrofurantoin is reduced inside bacterial cells to highly reactive intermediates … Read more
Introduction Nifedipine is a dihydropyridine calcium channel blocker widely used in the management of hypertension and angina. It primarily acts on vascular smooth muscle to produce vasodilation, thereby reducing blood pressure and improving coronary blood flow. Compared to non-dihydropyridines, nifedipine has a stronger effect on peripheral vasculature than on the heart. Mechanism of Action (Step-wise) … Read more
Introduction Nicorandil is an antianginal drug with a dual mechanism of action, combining nitrate-like properties with potassium channel–opening activity. It is used in the management of chronic stable angina to improve myocardial oxygen balance. By causing both arterial and venous vasodilation, nicorandil reduces cardiac workload and improves coronary blood flow. Mechanism of Action (Step-wise) A … Read more
Introduction Nefopam is a centrally acting non-opioid analgesic used for the management of moderate acute pain. It is distinct from NSAIDs and opioids, as it does not possess anti-inflammatory or opioid receptor activity. Nefopam is commonly used postoperatively and in musculoskeletal pain due to its analgesic properties without causing respiratory depression. Mechanism of Action (Step-wise) … Read more
Introduction Nebivolol is a third-generation, highly selective β1-adrenergic receptor blocker with additional vasodilatory properties. It is primarily used in the management of hypertension and heart failure. Unlike traditional beta-blockers, nebivolol uniquely enhances nitric oxide (NO) release, contributing to improved vascular function and reduced peripheral resistance. Mechanism of Action (Step-wise) A key exam point is that … Read more
