Ambien (Zolpidem) — Mechanism of Action Selective GABA‑A α1 subunit agonist: binds the benzodiazepine site on the GABA‑A receptor, enhancing chloride influx. Rapid onset (≈30 min) and moderate duration (~1–2 h) favor brief hypnotic effect without residual sedation. Minimal affinity for α2–α4 subunits → reduced anxiolytic, muscle‑relaxant, or anticonvulsant actions compared with non‑selective benzodiazepines. — Pharmacokinetics … Read more
Ambroxol Mechanism of Action Ambroxol is a mucolytic derivative of bromhexine that enhances mucociliary clearance by: Increasing pulmonary surfactant synthesis → lowers mucus surface tension and improves viscosity. Stabilizing lysosomal membranes and modulatin neutrophil degranulation → promotes effective cough clearance with less airway inflammation. Stimulation of ciliary beat frequency → accelerates mucus transport. These effects … Read more
Amiodarone Amiodarone is a long‑acting, multi‑class antiarrhythmic agent commonly used to treat serious ventricular arrhythmias and supraventricular tachyarrhythmias. Mechanism of Action Class III activity: Potassium channel (IKr, IKs) blockade prolongs repolarization and the QT interval. Class I(a) and III effects: Sodium channel blockade slows conduction, especially in diseased myocardium. Class IV-like β‑blockade: Reduces automaticity and Ca²⁺ … Read more
Amoxicillin Amoxicillin is a semi‑synthetic, broad‑spectrum β‑lactam antibiotic widely used to treat bacterial infections caused by gram‑positive and gram‑negative organisms. It is typically available as an oral formulation (capsule, chewable tablet, liquid) and as an intravenous formulation for severe infections. Mechanism of Action Inhibition of bacterial cell‑wall synthesis: Amoxicillin binds to penicillin‑binding proteins (PBPs) on … Read more
Amoxicillin and Clavulanate Amoxicillin combined with Clavulanate is a widely used oral beta‑lactam antibactericidal agent that provides expanded-spectrum activity against beta‑lactamase–producing organisms. — Mechanism of Action Amoxicillin: A penicillidin antibiotic that binds to penicillin‑binding proteins (PBPs) on the bacterial cytoplasmic membrane, inhibiting the transpeptidation step of peptidoglycan cross‑linking and thus weakening the cell wall. Clavulanate: … Read more
Amitriptyline Amitriptyline is a tricyclic antidepressant (TCA) with a broad spectrum of therapeutic uses beyond depression, including neuropathic pain, migraine prophylaxis, and sleep disorders. It acts primarily by inhibiting the reuptake of serotonin and norepinephrine, producing both antidepressant and analgesic effects. Mechanism of Action Amitriptyline exerts its pharmacologic effects through multiple pathways: Serotonin‑Norepinephrine Reuptake Inhibition … Read more
Amlodipine Mechanism of Action Amlodipine is a dihydropyridine calcium‑channel blocker (CCB) that selectively inhibits L‑type voltage‑dependent Ca²⁺ channels in vascular smooth muscle. It reduces intracellular Ca²⁺ influx, causing vasodilation of arteriolar beds ➜ ↓ systemic vascular resistance and arterial pressure. Minimal effect on cardiac conduction; at therapeutic doses it produces little change in heart rate … Read more
Ampicillin Ampicillin is a semi‑synthetic penicillin V derivative with a broad spectrum of activity against many Gram‑positive and Gram‑negative organisms. It is widely used for community‑acquired infections, prophylaxis in certain surgical settings, and as a first‑line agent in pediatric therapy. Mechanism of Action Inhibits bacterial cell‑wall synthesis by binding to and inactivating penicillin‑binding proteins (PBPs) that … Read more
Diazepam Mechanism of Action Diazepam is a benzodiazepine that potentiates the inhibitory neurotransmitter gamma‑aminobutyric acid (GABA). It binds to a specific allosteric site on the GABA_A receptor complex, increasing chloride ion influx. Resulting hyperpolarization diminishes neuronal excitability, producing anxiolytic, anticonvulsant, skeletal‑muscle relaxant, and hypnotic effects. Pharmacokinetics Absorption: Rapid oral bioavailability (~70 %), peak plasma concentration in … Read more
Ibuprofen Mechanism of Action Ibuprofen is a non‑selective cyclo‑oxygenase (COX‑1 and COX‑2) inhibitor. By blocking COX enzymes, it ↓ the conversion of arachidonic acid to prostaglandins, which are key mediators of inflammation, pain, and fever. The resulting ↓ prostaglandin synthesis alleviates acute pain and reduces inflammation, while also decreasing fever by acting on the hypothalamic … Read more