Gastrointestinal System Drugs Quiz

H2 receptor antagonists block histamine receptors on parietal cells, preventing the release of gastrin, a hormone that causes further histamine release. This ultimately blocks hydrochloric acid production and decreases pepsin production.

Cimetidine, ranitidine, famotidine, and nizatidine are medications that belong to this class.

Cimetidine, the first H2 antagonist, can cause gynecomastia and galactorrhea due to its antiandrogenic effects.

Famotidine is the only H2 antagonist approved for use in children aged 1 to 16 years old.

Nizatidine is the preferred H2 antagonist for individuals with liver dysfunction since it is eliminated by the kidneys, avoiding liver metabolism.

Proton pump inhibitors directly inhibit the H+, K+-ATPase enzyme system on parietal cells, effectively suppressing gastric acid secretion.

These drugs are used to treat various conditions associated with excess gastric acid production, including peptic ulcers, GERD, and Zollinger-Ellison syndrome.

Caution is advised during pregnancy and lactation due to potential fetal or infant adverse effects. Also, hepatic or renal dysfunction can interfere with drug metabolism and excretion.

Drugs that block the final step of acid production in the stomach, lowering acid levels and treating conditions like ulcers and GERD.

PPIs are rapidly absorbed from the gut and reach peak levels in 3-5 hours. They are extensively metabolized in the liver and excreted in urine.

PPIs are contraindicated in pregnant or breastfeeding women due to potential harm to the fetus or infant, and their safety hasn't been established in children under 18, except for lansoprazole.

PPIs can cause CNS effects like dizziness and headache, GI effects like diarrhea and abdominal pain, and respiratory symptoms like cough and stuffy nose.

Long-term PPI use has been associated with bone loss, decreased calcium and magnesium levels, and an increased risk of Clostridium difficile diarrhea and pneumonia.

Drugs used to relieve constipation, often available over-the-counter.

Frequent laxative use can lead to dependence and potentially chronic intestinal problems.

Abuse of laxatives can develop chronic intestinal disorders by disrupting natural bowel movements and potentially leading to dependency.

They directly irritate the nerve plexus in the intestinal wall, causing increased movement and stimulation of local reflexes.

They increase the bulk of fecal matter, making it easier to pass.

They help the intestinal contents move more smoothly, reducing friction.

They can worsen existing conditions like appendicitis, diverticulitis, and ulcerative colitis.

They work throughout the GI tract, starting from the small intestine and increasing motility.

They can cause diarrhea, abdominal cramping, and nausea.

They are contraindicated during pregnancy due to the risk of premature labour.

They should be used with caution in individuals with heart conditions or those who are weak, as they can affect electrolyte balance and absorption.

Laxatives that work by adding bulk to the stool, making it easier to pass. Examples include psyllium, methylcellulose, and polycarbophil.

These laxatives work by stimulating the muscles of the intestines to contract, pushing the stool along. Examples include bisacodyl and senna.

These laxatives work by drawing water into the intestines, softening the stool and making it easier to pass. Examples include magnesium hydroxide and polyethylene glycol.

These laxatives work by adding lubrication to the stool, making it easier to pass. Examples include docusate, glycerin, and mineral oil.

Common adverse effects of bulk laxatives are diarrhea, abdominal cramping, and nausea.

Common adverse effects of stimulant laxatives are diarrhea, abdominal cramps, and electrolyte imbalances.

Common adverse effects of osmotic laxatives are diarrhea, abdominal cramps, and dehydration.

Common adverse effects of lubricant laxatives are diarrhea, leakage, and staining.

These drugs are all taken orally, directly effective within the GI tract and generally not absorbed systemically. They act rapidly, causing effects as they pass through the GI tract.

Bulk laxatives are contraindicated in cases of acute abdominal issues like appendicitis, diverticulitis, and ulcerative colitis.

Laxatives should be used cautiously in individuals with heart block, coronary artery disease, and debilitation. Additionally, extreme caution is needed during pregnancy and lactation.

Polyethylene glycolelectrolyte solution should be used cautiously in patients with a history of seizures due to the risk of electrolyte absorption causing neuronal instability.

Cathartic dependence occurs when laxatives are used frequently over a long period, making the GI tract reliant on their stimulation. This can lead to constipation and stool drying without regular laxative use.

Frequent laxative use or abuse can cause adverse effects such as dizziness, headache, and weakness. These may be related to fluid and electrolyte imbalances accompanying laxative use.

Sweating, palpitations, flushing, and even fainting can occur after laxative use. These effects may be related to a sympathetic stress reaction to intense GI stimulation or electrolyte imbalances.

Bulk stimulants increase GI motility by increasing fluid in the intestinal contents, expanding bulk, stimulating stretch receptors, and activating localized activity.