Pharm Exam 3

Vomiting Center

located in medulla oblongata

Common Causes of Nausea/Vomiting

• GI disorders

• CV, infectious, neurologic or metabolic disorders

• AE of drug therapy or chemotherapy

• Pain and other noxious stimuli (sights, odors, motion sickness)

• Post-op (pain, impaired GI motility, meds)

• Pregnancy

• Migraines

Drug Therapies (antiemetics)

Phenothiazines
- Prochlorperazine (Compro)
Antihistamines
- Hydroxyzine (Vistaril)
5HT3 or Serotonin Receptor Antagonists
- Ondansetron (Zofran)
Substance P/Neurokinin 1 Antagonists
- Aprepitant (Emend)

Phenothiazines - Prochlorperazine (Compro)

• first generation antipsychotic + anti-emetic

  • depress CNS

• antagonizes D2 (dopamine) receptors in midbrain

• muscarinic (M1) and histamine (H1) blocking effects

• indications: chemo induced emesis, surgery nausea, anesthesia, migraines

• treats schizophrenia/psychosis in larger doses

• BEERS criteria (may be inappropriate in older adults)

• contraindications: glaucoma, elderly, kidney/liver dx, kids

• adverse effects: orthostatic hypotension antcholinergic effects (blurred vision, urinary retention, dry mouth, drowsiness, confusion, QT changes)

• monitoring: LOC, QT prolonged, I+O, constipation, N+V, BP

• black box: increase risk of death in elderly adults with dementia induced psycosis

Extrapyramidal Symptoms

Higher doses increase risk

• pseudoparkinsonism (stooped, shuffling, rigidity, bradykinesia, tremors at rest, pill-rolling monition of the hand)

• acute dystonia (facial grimace, involuntary eye movement, muscle spams of tongue, face, neck and back, laryngeal spasms

• akarthisia (restlessness, trouble standing still, paces the floor, constant rocking)

• tardive dyskinesia (tongue protrusion, sucking, smacking lips, chewing, involuntary movements)

Antistamines - Hydroxyzine (Visartil)

• block HI receptors in vestibular apparatus, blocks action of acetylcholine in brain

• variable half life (5 to 30H)

• indications: nausea, vomiting, sickness/vertigo, sedative for anxiety, anesthesia, combo drug

• contraindications: renal and hepatic impairement, early pregnancy, prolonged QT, Beers Criteria

• adverse effects: drowsiness, dizziness, confusion, dry mouth, thick respiratory secretions, blurred vision, urinary retention, tachycardia

• monitoring: symptoms relief, teaching/AES

• teaching: avoid opioids, safety (no driving)

5 Hydroxytryptamine3 (5HT3) or Serotonin Receptor Antagonists - Ondansetron (Zofran)

• drug of choice for chemo

• can be used in early pregnancy

• antagonizes serotonin receptors, activated by emetogenic drugs or toxins

• oral dissolving works within 30-60 mins

• contraindications: hypersensitivity, hepatic impairment

• adverse: diarrhea, headache, dizziness, constipation, fatigue, transient elevation of liver enzymes, prolonged QT

• monitor EKG, serotonin syndrome

• FDA warning for prolonged QT

Substance P/Neurokinin 1 Antagonists - Apprepitant (Emend)

• blocks activity of substance P at NK1 receptors in brain, inhibiting signal to brain that causes nausea

• highly protein bound

• indications: chemo related N/V (usually with 5HT3 and corticosteroids)

• contraindications: hypersensitivity, zides and prides

• patient teaching: interactions, timing, contraceptives

• adverse effects: fatigue, weakness, dizziness, abnormal heart rhythm, headache, hiccups

• monitoring: symptom relief, heart rhythm

Synthetic Cannabinoids

• marijuana

• dronabinol and nabilone

• schedule 1

• alternative therapy

• prolonged use can cause hyperemesis

Nonpharmacologic Nausea Interventions

• ginger

• acupuncture

Constipation

• infrequent and painful expulsion of hard, dry stools

• symptom, not a disease

• difficult to define clearly

• 3 or fewer per week

• know patient baseline

Risk Factors

• diet

• lifestyle, particularly low levels of physical activity

• age

• some drugs

• disease processes

Prevention of Constipation

• diet, exercise, and fluid intake in promoting normal bowel function

• increase activity and exercise

• increase intake of dietary fiber

• drink at least 6-10 glasses of water

• establish and maintain a routine for bowel elimination

Laxative Types

• Bulk forming (psyllium): add mass to feces, take with water, best for long-term

• Lubricants (mineral oil): lubricate and slow colonic absorption of water from mass, can cause lipid aspiration pneumonia

• Surfacants/Softeners (docusate sodium/colace): decrease the surface tension of the mass to allow water to penetrate

Psyllium (Metamucil)

fiber supplement
contraindications/cautions: undiagnosed abdominal pain, obstruction, impaction, children, overuse in older adults
adverse effects: flatulence, bloating, cramping, bowel obstruction
patient teaching: take with 8oz of water, may reduce or delay absorption
evaluation: relief, severe stomach pain, N/V, rectal bleeding, constipation > 7

Docusate Sodium

• surfactant laxative

• softens stool, does not actively expel stool

• main goal is to reduce strain

• should be taken daily

Cathartics

• stimulate cathartics

• saline laxatives

Stimulant Cathartics

• the strongest and most abused laxative products

• irritate the GI mucosa, pull water into colon, stimulate peristalsis

• they produce a watery stool and may lead to fluid, electrolyte and acid-base imbalances

Saline Cathartics

• increase the osmotic pressure in the intestinal lumen, resulting in the retention of water, which distends the bowel and stimulates peristalsis

• they produce a semifluid stool and may lead to fluid and electrolyte imbalances

Bisacodyl (Dulcolax)

contraindications: undiagnosed abdominal pain, obstruction, impaction, children <6 years, limit during pregnancy, overuse in adults
adverse effects: abdominal pain, cramping, nausea, diarrhea, weakness, electrolyte imbalance
pt education: don’t take with milk, or empty stomach or at bedtime
evaluation: relief?

Other Dulcolax Indicators

• obtain a stool specimen for parasitoligic contamination

• accelerate excretion of parasites after anthelmintic drugs have been administered

• reduce serum cholesterol levels

Guanylate Cyclase-C Agonist - Linaclotide/Linzess

• increases secretion of chloride and water in intestines

• treats IBC-C and idiopathic constipation

• adverse effects: diarrhea, ABD pain, headache, dehydration

• assessment: pain relief, BM, possible cramping

• contractions: bowel obstruction, children younger than 2

• black box warning: dehydration

Lactulose

exerts an osmotic effect, pulls water in and stimulates peristalsis

treats hepatic encephalopathy by decreasing the production of the waste product ammonia

Sorbitol

is often given with sodium polystrene sulfonate in the treatment of hyperkalemia to aid in the expulsion of the potasssium-renin complex

Lubiprostone

aids in treating chronic idiopathic constipation by increasing intestinal fluid secretion, stimulating intestinal motility and defacation

Diarrhea

• symptom, not disease

• increased bowel motility

• frequent liquid or semi liquid stool

• 24-48 hours

• body is trying to get rid of toxins, irritants, infectious agents

Causes of Diarrhea

• excessive use

• laxative abuse

• intestinal infections from protozoa, virus and bacteria

• lack of digestive enzymes

• undigested course or highly spiced food in GI tract

• inflammatory bowel disorders

• irritable bowel syndrome

• drugs

• functional disorders - stress/anxiety

• surgical incision of bowel

• intestinal neoplasms

• HIV

• AIDS

Chrons Disease

• chronic, recurrent inflammation

• can affect any area of GI tract, patchy lesions

• often RLQ

• fever, bleeding, diarrhea, anorexia, weight loss

Ulcerative Colitis

• chronic, recurrent inflammation

• most often affects colon and rectum, continous secretion

• pain after LLQ

• blood and mucus in stool, severe pain, diarrhea, anorexia, weight loss

Intestinal Infections

• bacteria: e.coli, salmonella, shigella, clostridium difficile

• virus: rotavirus, calicuivirus

• protozoa: giardia lambia, cryptospridium parvum

Nursing Care/Education

• fluid replacement

• bland diet

• monitor fluid and electrolyte balance

• drug therapy

Opiate Related Antidiarrheals

• diphenoxylate with atropine sulfate (lomotil)

• loperamide (immodium)

• paregoric

Adjuvant Antidiarrheal Medications

• alosetron

• bismuth subsalicylate

• cholestryamine

• colestipol

• nitazoxine

• octreatide

• pancreatin or pancrelipase

• polycarbophil preparations

• rifaximin

Diphenoxylate with Atropine (Lomotil)

• prototype used to treat moderate to severe diarrhea

• slows peristalsis by acting on the smooth muscles in the intestine

caution: children, breastfeeding, kidney and liver impairment
adverse: tachycardia, dizziness, headache, flushing, nausea and vomiting, dry skin and mucous membranes and urinary retentions
hypotension and respiratory depression have occurred with larger doses than ordered

Diphenoxylate with Atropine (Lomotil)