Metoclopramide is a dopamine receptor antagonist and serotonin receptor agonist primarily used as an antiemetic and gastroprokinetic agent. It’s been a workhorse in our gastroenterology and oncology departments for decades, though its reputation has certainly evolved over the years. I remember the first time I prescribed it was for a young woman with diabetic gastroparesis back in my residency - we were desperate for something to help her keep food down, and metoclopramide was what the senior consultant reached for without hesitation.
Amantadine is a fascinating pharmaceutical agent that has worn many hats throughout its clinical lifespan. Initially developed as an antiviral compound in the 1960s, its unexpected efficacy in Parkinson’s disease symptoms created an entirely new therapeutic pathway. Today, it occupies a unique niche in neurology, particularly for Parkinson’s-related dyskinesias and fatigue in multiple sclerosis. Its mechanism—primarily as an NMDA receptor antagonist with some dopaminergic activity—makes it pharmacologically distinct from other agents.
Cabgolin represents one of those interesting cases where a well-established pharmaceutical agent finds surprising applications beyond its original indications. As a dopamine receptor agonist with high specificity for D2 receptors, its primary mechanism involves suppressing prolactin secretion from the anterior pituitary. We initially understood it purely as a hyperprolactinemia treatment, but over two decades of clinical use, we’ve observed unexpected benefits in areas like metabolic syndrome and certain inflammatory conditions. The formulation typically comes in 0.
Compazine, known generically as prochlorperazine, is a phenothiazine derivative primarily used as an antiemetic and antipsychotic agent. This prescription medication has been a cornerstone in managing nausea, vomiting, and certain psychiatric conditions since its introduction in the 1950s. Unlike over-the-counter supplements, Compazine represents a well-established pharmaceutical intervention with specific clinical applications and regulatory oversight. I remember my first encounter with Compazine during residency—we had a postoperative patient, Mr. Henderson, 68, with unrelenting nausea after abdominal surgery.
Dimenhydrinate, marketed under the brand name Dramamine, represents one of the most widely recognized over-the-counter medications for motion sickness prevention and treatment. This antihistamine derivative has maintained clinical relevance since its introduction in the 1940s, offering predictable symptomatic relief for various forms of kinetosis. What’s particularly interesting about dimenhydrinate is its dual-component nature - it’s actually a chemical combination of diphenhydramine and 8-chlorotheophylline in a 1:1 ratio, which creates a product with different properties than either component alone.
Erythromycin is a macrolide antibiotic derived from Streptomyces erythreus, first isolated in 1952. It’s available in oral tablets, topical solutions, ophthalmic ointments, and intravenous formulations. The drug works by binding to the 50S ribosomal subunit, inhibiting bacterial protein synthesis. We initially used it primarily for penicillin-allergic patients, but its applications have expanded significantly over decades of clinical use. The interesting thing about erythromycin - and this isn’t in most textbooks - is how its gastrointestinal prokinetic effects were discovered accidentally when patients receiving it for infections reported improved gastric emptying.
Fosfomycin is a broad-spectrum bactericidal antibiotic originally isolated from strains of Streptomyces fradiae. It represents a unique chemical class of phosphonic acid antibiotics and has been used clinically for decades, primarily for uncomplicated urinary tract infections. Its mechanism of action is distinct from other antibiotic classes, inhibiting bacterial cell wall synthesis at an early stage by targeting the enzyme MurA (UDP-N-acetylglucosamine enolpyruvyl transferase). This monograph will examine the evidence base for fosfomycin, particularly its oral formulation fosfomycin trometamol, covering its pharmacokinetics, clinical applications, safety profile, and role in the era of increasing antimicrobial resistance.
Kytril, generically known as granisetron, is a selective 5-HT3 receptor antagonist primarily used for the prevention and treatment of chemotherapy-induced and radiotherapy-induced nausea and vomiting. It’s available in oral tablet, oral solution, and injectable forms, with the injection also approved for postoperative nausea and vomiting. The drug works by blocking serotonin receptors in the gut and brain, which are key triggers for the vomiting reflex. Its development marked a significant advancement in supportive cancer care, allowing patients to tolerate more aggressive treatment regimens.
Domperidone, marketed under the brand name Motilium among others, is a dopamine antagonist with specific peripheral effects that’s been used clinically for decades, primarily as an antiemetic and gastroprokinetic agent. Unlike some other dopamine antagonists, it doesn’t readily cross the blood-brain barrier, which gives it a distinct side effect profile that’s been both its advantage and limitation in various clinical contexts. We initially thought it was just another anti-nausea medication until we started noticing its profound effects on gastric emptying in diabetic patients.
