Alterations in Elimination - Drugs

Phenothiazines

First generation antipsychotic drugs that depress the CNS; act by blocking dopamine from receptor sites in the brain and CTZ

Promethazine

Phenothiazine; TX of N/V associated with surgery, anesthesia, migraines, chemotherapy & motion sickness. NOT for subcutaneous admin.

Adverse Effects - Promethazine

Blurred vision

Urinary retention

Dry mouth

Photosensitivity

Drowsiness

Confusion (Anticholinergic properties)

Antihistamines

Used to prevent histamine from exerting its effects on tissue; relieves N/V by blocking action of acetylcholine in brain

Hydroxyzine

Antihistamine; TX of N/V associated with surgery, anesthesia, migraines, chemotherapy, & motion sickness, potential congenital defects; IM preferred

Adverse Effects - Hydroxyzine

Drowsiness

Dizziness

Confusion

Dry mouth

Thick, respiratory secretions

Blurred vision

Urinary retention

Tachycardia (Anticholinergic properties)

5-HT3 Serotonin Receptor Antagonists

Antagonize serotonin receptors, preventing their activation by the effects of emetogenic drugs/toxins

Ondansetron

5-HT3; treat moderate to severe N/V associated with cancer chemo, radiation therapy, and postop status; not to be taken with apomorphine.

Adverse Effects - Ondansetron

Diarrhea

Dizziness

Constipation

Fatigue

Transient elevation of liver enzymes

Pain at injection site

Substance P/Neurokinin 1 Antagonists

Blocks activity of substance P at NK1 receptors in brain; inhibits signal to brain that causes nausea

Aprepitant

Substance P/Neurokinin1 Antagonist; TX of acute and delayed N/V associated with chemotherapy; prevention of postop N/V; reduces oral contraceptives up to 28 days after admin.

Bulk Forming Laxatives

Swells when water is added; gel-like substance that stimulates peristalsis and defecation; closest to fiber.

Psyllium

Bulk forming laxative; occasional constipation, TX of diarrhea, lower cholesterol when combined w/ diet; admin. with 8 oz water, best if required daily,

Adverse Effects - Psyllium

Severe flatulence

Bloating

Abdominal cramping (Do not admin. with undiagnosed abd. pain)

Esophageal or bowel obstruction

Stimulant Cathartic

Stimulates & irritates the GI mucosa & pulls water into bowel lumen, feces move through bowel too rapidly to allow colonic absorption of fecal water = elimination of a water stool

Bisacodyl

Stimulant Cathartic; relief of constipation, bowel prep, management of neurogenic bowel dysfunction. Not to be taken w/in 1 hr of ingesting milk or antacid, oral should be taken empty stomach at bedtime.

Adverse Effects - Bisacodyl

Abdominal pain (do not admin. w/ undiagnosed abd. pain)

Cramping

Nausea

Diarrhea

Weakness

Surfactant Laxatives (Stool softeners)

Docusate Calcium or Docusate Sodium; decreases surface tension of fecal mass to allow water to penetrate stool; prevents straining

Saline Cathartics

Increases osmotic pressure in intestinal lumen to get water retention; can produce fluid and electrolyte imbalances

PEG

Saline Cathartic; TX occasional constipation. should not be taken longer than 2 wks, pt. should fast 3-4 hrs prior to taking, refrigerate; NO electrolyte solution

Adverse Effects - PEG

Cramping

Nausea

Abdominal distention

Bloating

Flatulence

Ischemic colitis

PEG-ES

Saline Cathartic; bowel cleansing before GI examination, electrolyte solution, clear liquid diet

Adverse Effects - PEG ES

Cramping

Nausea

Bloating

Rectal Irritation

Weakness

Opiate Related Antidiarrheal

Most effective agents for symptomatic TX of diarrhea.

Diphenoxylate with Atropine Sulfate

Opiate related antidiarrheal; TX. of moderate to severe diarrhea, not for children <2, not used for diarrhea caused by toxic materials

Adverse Effects - Diphenoxylate with Atropine Sulfate

Tachycardia

Dizziness

Headache

Flushing

N/V

Dry skin

Urinary retention

Hypotension

Respiratory depression

Lactulose

Disaccharide; TX. constipation and hepatic encephalopathy, given with water/juice on empty stomach, increases blood sugar

Lubiprostone

Chloride Channel Activator; TX chronic constipation, irritable bowel syndrome w/ constipation, opioid-induced constipation, methadone decreases effect

Linaclotide

14-Amino Acid Peptide; TX of chronic constipation and irritable bowel syndrome w// constipation; avoided in children 6-17, admin. on empty stomach 30 min before first meal, BBW against children younger than 6