P&T Nausea & Vomiting

• Nausea is the unpleasant feeling or sensation that may be immediately followed by vomiting
• Vomiting is the expulsion of gastric content. This is NOT voluntarily controlled
• Retching is the movement of abdominal and thoracic muscles before vomiting.

Involves Brain and GI.

• Chemoreceptor trigger zone, with neurotransmitters dopamine and serotonin.
• Vestibular apparatus
• Cerebral cortex
• Visceral GI tract afferent nerves

Chemoreceptor trigger zone (CTZ)

True

Drug Induced : Opioid family, narcotics (Primary reason), cardiac glycosides, Broncodilators (digoxin, theophylline), antibiotics

Medical conditions: Fluid & electrolyte disorders, pregnancy, GI obstruction, Increase Intracranial pressure, Surgery, peritonitis, dysfunctional bowel syndrome, metastasis, etc.

• 1) Dehydration
• 2) Aspiration
• 3) Malnutrition
• 4) Electrolyte or acid/base abnormalities
• 5) Esophageal tears

To determine the cause and use of the most appropriate agent(drug)

• Example: Gastroenteritis is due to food eaten. Usually short lived, can use compazine.
• CINV: can be severe. Always pre-treat, continue for 24-72 hrs after therapy

• False.
• 2x higher in children than adults.

• 1.) Female
• 2.) Non-smoker
• 3.) Family Hx of motion sickness/PONV
• 4.) Long surgeries (2-3 hrs) OR use of nitrous oxide
• 5.) Post-operative use of opioids

True.

• 1.) Dietary
• 2.) Physical
• 3.) Pscyhological

• 1.) Relaxation
• 2.) Biofeedback (?)
• 3.) Self hypnosis
• 4.) Cognitive distraction
• 5.) Guided imagery
• 6.) Systematic desensitization
• 7.) Accupressure therapy

• 1.) 5 HT3 receptor antagonists (serotonin antagonists)
• 2.) Anticholinergics (including antihistamines)
• 3.) Antidopaminergics (including phenothiazines)
• 4.) Misc.

• 1.) prochlorperazine (Compazine)*
• 2.) chlorpromazine (Thorazine)
• 3.) thiethylperazine (Torecan)
• 4.) promethazine (Phenergan)

5-10 mg PO q 4-6 hrs

5-10 mg IM q 3-4 hrs

2.5 - 10 mg IV q 3-4 hrs

25 mg rectally q 6 hrs

• - Sedation (most common)
• - anticholingeric effects
• - alpha adrenergic blocking effects
• - EPS

Do not use in children under 2 years of age.

True.

Use caution --> very caustic to tissues, must be diluted, and administered only into a large vein or central venous site.

Start with a low dose = 6.25 - 12 mg over 10 -15 mins.

promethazine (Phenergan).

• 1.) phenothiazines
• 2.) butyrophenones
• 3.) benzamides

• - muscle spasms
• - restlessness
• - gait disturbances

*Children and elderly patients*

• 1.) haloperidol (Haldol)
• 2.) droperidol (Inapsine)

• False.
• Used only when other treatments fail.

• - sedation
• - somnolence (drowsiness/sedation)
• - dystonic reactions (movement disorder)

QT prolongation or Torsades de pointes may occur.

Only used in cases pre-operative anaesthesia.

metoclopramide (Reglan)

• True.
• Its a serotonin blocker at higher doses

• mso-header-margin:.5in;
• mso-footer-margin:.5in;
• mso-paper-source:0;}
• div.Section1
• {page:Section1;}
• -->

• à

• -sedation
• -diarrhea
• -restlessness
• -anxiety
• -EPS

Children. Due to the risk of EPS

dexamethasone (Decadron) - used on a short-term basis

Its used as a last resort, but routinely used in CINV.

5-HT3

• 1.) ondansetron (Zofran) **Need to know dosing
• 2.) granisetron (Kytril)
• 3.) dolasetron (Anzemet)
• 4.) palonosetron (Aloxi)

True

• Tablet - 4, 8 and 24 mg
• Oral disintegrating - 4 and 8 mg
• Solution - 4mg/5ml
• Injection - 2 mg/ml and 32 mg/50 ml

• 1.) IV 4 mg usually given for pre-op (1 dose)
• 2.) PONV: 4 mg IV/IM before induction of anesthesia or at onset of N/V
• 3.) Chemo-induced
• a) by mouth 8-32 mg BID-TID
• b) IV: three 0.15 mg/kg doses (1/2 pre, then 4 & 8 hrs post) or single 32 mg dose

True.

Elevation in liver transaminases, constipation, diarrhea or QT interval prolongation

aprepitant (Emend)

• - CINV
• - PONV
• - Post-operative gastric motility

aprepitant is ONLY used for CINV.

aprepitant (Emend) inhibits CYP3A4, reducing the efficacy of oral birth control pills.

• - diphenhydramine (Benadryl)
• - dymenhydrinate (Dramamine)
• - meclizine (Antivert)
• - trimethobenzamide (Tigan)
• - scopolamine (Transderm Scop)

True.

• - Drowsiness/sedation
• - Dry mouth
• - Blurred vision
• - Children have a paradoxical experience (insomnia)

trimethobenzamide (Tigan)

lorazepam (Ativan)

• Treatment for anticipated N&V.
• For example, as pre-chemotherapy treatment.

Sedation

• True.
• Schedule II

• - dronabinol (Marinol)
• - nabilone (Cesamet)

CINV

• - CNS effects
• - dizziness
• - dysphoria
• - mood & sensory changes
• - paranoid ideation
• - blurred vision
• - hypotension
• - tachycardia

*First ensure the patient has stable airway and respiratory activity

• - diphenhydramine
• 0.7-1 mg/kg/dose IV/PO q 4-6 hrs PRN
• - benztropine (Cogentin)
• 1-2 mg IV/PO q 4-6 hrs PRN (works faster)

True.

• False.
• Most cases are due to a deficiency in pyridoxine (Vit B6). Give this first. If N&V does not subside, consider anti-emetics.

• - aprepitant (Emend)
• - dexamethasone (Decadron)
• - Serotonin 5 HT3 receptor antagonists

Gastroenteritis is short lived and self limiting, but can be treated with prochlorperazine (Compazine)