Introduction Calcitonin is a peptide hormone produced by the parafollicular (C cells) of the thyroid gland and is also available as a therapeutic agent (salmon calcitonin). It plays an essential role in calcium and bone metabolism, acting as a physiological antagonist to parathyroid hormone (PTH). The Mechanism of Action of Calcitonin centers on inhibition of … Read more
Introduction Buspirone is an anxiolytic medication primarily used for the treatment of generalized anxiety disorder (GAD). Unlike benzodiazepines, it does not cause sedation, dependence, or withdrawal symptoms, making it a preferred long-term therapy option. The Mechanism of Action of Buspirone is unique among anxiolytics. It acts mainly as a partial agonist at 5-HT1A serotonin receptors, … Read more
Introduction Buscopan (Hyoscine Butylbromide) is an antispasmodic drug widely used to relieve smooth muscle spasms in the gastrointestinal tract, biliary tract, urinary tract, and female reproductive system. It is commonly used for abdominal cramps, renal colic, biliary colic, irritable bowel syndrome (IBS), and dysmenorrhea. The Mechanism of Action of Buscopan is primarily based on peripheral … Read more
Introduction Bupivacaine is a long-acting amide-type local anesthetic widely used for regional anesthesia, epidural anesthesia, nerve blocks, infiltration anesthesia, and obstetric analgesia. It is known for its high potency, long duration of action, and strong sensory blockade. Because of its strong affinity for cardiac sodium channels, it carries a higher risk of cardiotoxicity compared to … Read more
Bumetanide is a potent loop diuretic, structurally related to furosemide but approximately 40 times more potent. It is used in the management of edema associated with heart failure, liver cirrhosis, nephrotic syndrome, and renal impairment, as well as acute pulmonary edema. The Mechanism of Action of Bumetanide involves inhibition of sodium, potassium, and chloride reabsorption … Read more
Introduction Bronchodilators are a broad class of drugs used to relieve bronchoconstriction, improve airflow, and treat respiratory disorders such as asthma, COPD, and bronchospasm. They work by relaxing airway smooth muscle, reducing airway resistance, and enhancing ventilation. The main drug classes that act as bronchodilators include: Each class uses a different mechanism, but all ultimately … Read more
Introduction Bromocriptine is a dopamine D2 receptor agonist used in the treatment of Parkinson’s disease, hyperprolactinemia, acromegaly, and type 2 diabetes mellitus (bromocriptine-QR). As an ergot-derived dopamine agonist, it mimics the action of dopamine on pituitary and central nervous system receptors. Its mechanism of action involves inhibiting prolactin secretion, activating dopaminergic pathways, and modulating hypothalamic … Read more
Introduction Brimonidine is a selective alpha-2 adrenergic receptor agonist primarily used in the management of open-angle glaucoma and ocular hypertension. It is also used topically for facial erythema in rosacea. By activating alpha-2 receptors, brimonidine reduces aqueous humor production and enhances uveoscleral outflow, leading to decreased intraocular pressure (IOP). Its dual mechanism, neuroprotective potential, and … Read more
Introduction Bosentan is an oral endothelin receptor antagonist (ERA) used primarily for the treatment of pulmonary arterial hypertension (PAH). Endothelin-1 (ET-1) is one of the most potent vasoconstrictors in the human body, and its overactivity plays a central role in the pathophysiology of PAH by causing vasoconstriction, vascular hypertrophy, smooth muscle proliferation, and fibrosis. Bosentan … Read more
Introduction Bleomycin is a cytotoxic glycopeptide antibiotic used as an antineoplastic agent, especially in the treatment of Hodgkin lymphoma, testicular cancer, squamous cell carcinomas, and germ cell tumors. It is unique among chemotherapeutic agents because it causes minimal myelosuppression but is strongly associated with pulmonary toxicity. Bleomycin acts primarily during the G2 phase of the … Read more
