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Drugs Affecting GI Tract Motility: Dopamine Receptor Antagonists01:28

Drugs Affecting GI Tract Motility: Dopamine Receptor Antagonists

Prokinetic agents are specialized medications that stimulate gastrointestinal (GI) motility, promoting food movement through the GI tract. Dopamine, an inhibitory neurotransmitter, plays a significant role in this process, reducing GI motility and indirectly controlling the speed of digestion. Dopamine receptor antagonists, such as metoclopramide and domperidone, offer a unique advantage as prokinetic agents. By blocking the dopamine receptors, these drugs increase GI motility, improving food...
Direct-Acting Cholinergic Agonists: Therapeutic Uses01:11

Direct-Acting Cholinergic Agonists: Therapeutic Uses

Direct-acting cholinergic agonists have many therapeutic uses in various medical fields. Choline esters, including acetylcholine, have limited clinical utility due to their non-selectivity and short duration of action. Still, acetylcholine and carbachol are applied topically during ophthalmologic surgery to induce miosis. Pilocarpine, a muscarinic and ganglionic stimulator, effectively treats open-angle glaucoma and alleviates xerostomia and dry mouth caused by radiotherapy or Sjögren syndrome.
Adrenergic Antagonists: Pharmacological Actions of ɑ-Receptor Blockers01:22

Adrenergic Antagonists: Pharmacological Actions of ɑ-Receptor Blockers

α-Adrenergic antagonists, known as α-blockers, exert their effects by inhibiting α-adrenoceptors, leading to specific physiological actions. α1-blockers and α2-blockers have distinct pharmacological actions and therapeutic applications.
α1-blockers: These drugs inhibit α1-adrenoceptors on smooth muscle cells, resulting in vasodilation. This vasodilation lowers blood pressure, making α1-blockers valuable in treating hypertension. Additionally, α1-blockers effectively address urinary obstruction...
Chemotherapy-Induced Nausea and Vomiting: 5-HT3 Receptor Antagonists01:27

Chemotherapy-Induced Nausea and Vomiting: 5-HT3 Receptor Antagonists

5-HT3 receptor antagonists, such as dolasetron, granisetron (Kytril), ondansetron (Zofran), and palonosetron (Axoli), are crucial in managing chemotherapy-induced nausea and vomiting (CINV) and postoperative nausea. These drugs selectively block 5-HT3 receptors in the visceral vagal and spinal afferent nerves, chemoreceptor trigger zone, and the vomiting center. They have a rapid onset of action and can be given as a single dose before chemotherapy. Ondansetron and granisetron, in particular,...
Drugs for Peptic Ulcer Disease: Prostaglandin Analogs as Mucosal Protective Agents01:20

Drugs for Peptic Ulcer Disease: Prostaglandin Analogs as Mucosal Protective Agents

The gastric mucosa produces prostaglandins E2 (PGE2) and prostacyclin (PGI2), crucial in maintaining gastric health. They exert cytoprotective effects, including increasing bicarbonate secretion, releasing protective mucin, reducing gastric acid output, and preventing harmful vasoconstriction. These effects are mediated through various receptors, such as EP1, EP2, EP3, and EP4.
Non-steroidal anti-inflammatory drugs (NSAIDs) can induce peptic ulcers by inhibiting cyclooxygenase, decreasing...
Drugs Acting on Autonomic Ganglia: Blockers01:28

Drugs Acting on Autonomic Ganglia: Blockers

Ganglionic blockers inhibit autonomic activity by blocking nicotinic receptors in the autonomic ganglia, suppressing impulse transmission. These blockers lack selectivity between sympathetic and parasympathetic ganglia and are ineffective as neuromuscular junction antagonists. They can be categorized into two groups: