NURS 615 Exam 4 Study Guide

Laxatives that work by irritating the intestinal lining, causing increased muscle contractions and faster bowel movements. Examples include cascara, senna, bisacodyl, and castor oil.

Laxatives that work by drawing water into the intestines, softening stool and increasing its volume, leading to easier bowel movements. Examples include magnesium hydroxide, magnesium citrate, sodium phosphate, and polyethylene glycol (PEG) 3350.

Laxatives that work by absorbing water and swelling in the intestines, adding bulk to stool and promoting regular bowel movements. Examples include psyllium, methylcellulose, and polycarbophil.

Laxatives that work by coating the stool and intestinal walls, making it easier for stool to slide through the intestines. An example is mineral oil.

Laxatives that work by lowering the surface tension of stool, allowing water to penetrate more easily and soften the stool. Examples include docusate medications (sodium, calcium, and potassium).

Bisacodyl is a stimulant laxative. It works by increasing fluid and salt in the intestines, leading to bowel movements. It irritates the intestinal lining, triggering contractions and promoting stool movement.

Osmotic laxatives, like magnesium hydroxide or polyethylene glycol, draw water into the intestines by increasing the osmotic pressure. This increased fluid volume stretches the gut, promoting peristalsis and bowel movements.

Bulk-forming laxatives like psyllium or methylcellulose absorb water in the intestines, creating a larger, softer stool. The increased bulk stretches the intestinal wall, stimulating peristalsis.

Mineral oil coats the stool and makes it easier to pass by reducing friction. It also softens the stool by trapping water in the intestines.

Stimulant laxatives like bisacodyl are contraindicated in individuals with cardiovascular diseases. They are also not recommended for pregnant women using castor oil, as it can induce uterine contractions.

H2 receptor blockers reduce gastric acid production by blocking the histamine-2 receptors on gastric parietal cells. They are primarily used to treat GERD and peptic ulcer disease.

Common H2 receptor blockers include cimetidine, ranitidine, famotidine, and nizatidine.

H2 receptor blockers are not anticholinergic as they do not block the histamine-1 receptors.

H2 receptor blockers can cause several adverse effects including: antiandrogenic effects (gynecomastia, erectile dysfunction), cardiac rhythm abnormalities, CNS alterations, hematologic issues, GI problems, vitamin B12 deficiency, and immune-related reactions.

Metoclopramide is used in treating GERD, diabetic gastroparesis due to its prokinetic properties. It stimulates gastric motility without affecting secretions.

Metoclopramide is used less often due to its serious adverse effects, especially Extrapyramidal Symptoms (EPS) which are particularly common in younger and older populations.

Metoclopramide does not heal esophageal lesions. It mainly improves gastric motility, but it doesn't address the root cause of GERD.

Surfactant laxatives, like docusate, are used to soften stool and prevent constipation, especially when dealing with dry and difficult stool. They help make bowel movements easier and reduce straining.

Hyperosmolar laxatives like glycerin and lactulose draw water into the intestines, making the stool more fluid and easier to pass. This effect is achieved through different mechanisms depending on the specific laxative.

Lubiprostone is a Cl channel activator. It works by increasing chloride secretion in the intestines, which helps soften the feces and improves bowel movement.

Opioid receptor antagonists like methylnaltrexone work by blocking opioid receptors in the gut, which speeds up peristalsis and helps relieve constipation caused by opioid medications.

Kaolin and pectin absorb liquid in the stool, making it thicker and easier to manage, especially in cases of uncomplicated acute diarrhea.

Bismuth subsalicylate acts as an antisecretory, anti-inflammatory, and antimicrobial agent. This helps reduce diarrhea by reducing fluid secretion and fighting off potential infections.

Both diphenoxylate and loperamide work by slowing down peristalsis in the intestines, effectively reducing the frequency and volume of bowel movements.

Bismuth subsalicylate contains salicylate, which can lead to Reye syndrome, a life-threatening condition, in children with febrile viral illnesses, such as influenza.