Related Concept Videos

Treatment for Pulmonary Arterial Hypertension: Phosphodiesterase Inhibitors01:28

Treatment for Pulmonary Arterial Hypertension: Phosphodiesterase Inhibitors

Phosphodiesterase 5 (PDE5) inhibitors are potent enzymes that function to hydrolyze cyclic nucleotides to their corresponding 5' monophosphates. Their unique biochemical properties have been applied in treating Pulmonary Arterial Hypertension (PAH).
Among the PDE5 inhibitors, sildenafil (Revatio) stands out as a competitive and selective inhibitor. It operates by elevating cellular levels of cGMP and augmenting signaling through the cGMP-PKG pathway, promoting vasodilation. Upon oral...
Esophageal Strictures-II: Clinical Features and Management01:26

Esophageal Strictures-II: Clinical Features and Management

Patients with esophageal strictures often experience a range of symptoms. Initially, they may have difficulty swallowing solid foods, which can progress to include liquids. Additional symptoms may involve chest pain or discomfort, regurgitating food and fluids, heartburn, unintentional weight loss, coughing or choking during meals, and hoarseness.
Healthcare providers should gather a comprehensive medical history and conduct a physical examination for diagnosis. If esophageal stricture is...
Esophageal Achalasia01:27

Esophageal Achalasia

Esophageal achalasia is a chronic neurogenic disorder characterized by impaired relaxation of the lower esophageal sphincter (LES) and absent or ineffective peristalsis in the distal esophagus. This leads to a functional obstruction without a physical blockage, despite significant disruption of esophageal motility.EtiologyAchalasia is caused by degeneration of the myenteric (Auerbach's) plexus, specifically the loss of inhibitory ganglion cells that produce vasoactive intestinal peptide (VIP)...
Gastroesophageal Reflux Disease01:25

Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is the backward flow of stomach contents (acid, pepsin, or bile) into the esophagus, causing mucosal inflammation known as esophagitis. It results from failure of antireflux mechanisms, mainly the lower esophageal sphincter (LES), influenced by mechanical and physiological factors.Etiology and Risk FactorsGERD develops when LES function is weakened or when intra-abdominal pressure increases. Risk factors include aging, obesity, and sliding hiatal hernia,...
Barrett Esophagus-II: Clinical Manifestations and Management01:21

Barrett Esophagus-II: Clinical Manifestations and Management

Individuals with Barrett's esophagus are often asymptomatic, but they may experience symptoms commonly associated with GERD, such as heartburn and acid regurgitation. Additional symptoms can include difficulty swallowing, chest pain, unintentional weight loss, blood in the stool (which may appear black, tarry, or bloody), and episodes of vomiting.
To diagnose Barrett's esophagus, healthcare providers often recommend an endoscopy for those showing symptoms of acid reflux. The procedure entails...
Effect of Hepatic Disease on Pharmacokinetics: Dose Adjustments Due to Hepatic Impairment01:08

Effect of Hepatic Disease on Pharmacokinetics: Dose Adjustments Due to Hepatic Impairment

Hepatic impairment, characterized by decreased liver function, does not uniformly mandate adjustments in drug dosage. Whether dosage modifications are necessary depends on various factors related to the drug's metabolism and elimination pathways. If a drug is primarily excreted via the kidneys and bypasses significant hepatic processing, if it undergoes minimal metabolic transformation in the liver, or if it is volatile and primarily expelled through the lungs, dose adjustments may not be...