II. Pathophysiology
- See Vomiting
- Images
III. Causes: General
- Common Causes- Small Bowel Obstruction
- Autonomic failure
- Hypercalcemia
- Narcotic bowel Syndrome- Disappears 2-3 weeks after starting Narcotic
- Associated with Intracranial Pressure
 
 
- Mnemonic: 11 M's- Metastases (Cerebral, Liver)
- Meninges irritated (Increased Intracranial Pressure)
- Movement (Vestibular stimulation)
- Mentation (Anxiety)
- Medications (Opioids, Chemotherapy, NSAIDs)
- Mucosal irritation (NSAIDs, GERD, Hyperacidity)
- Mechanical obstruction (Constipation, Tumor, Cancer Related Bowel Obstruction)
- Motility (Ileus, Opioids)
- Metabolic (HypercalcemiaHyponatremia, Uremia)
- Microbes (Local infection, Sepsis)
- Myocardial dysfunction (ischemia, CHF)
 
IV. Causes: Chemotherapy
V. Approach: General Rules
- Attempt to identify a cause
- Consider combining Antiemetics if one not effective- Use from different classes
 
- Avoid Nasogastric Tubes
VI. Management: General
- Always consider non-pharmacologic management first- Small Frequent Meals
- Avoid bland foods (patient eats what they want)
 
- Starting Antiemetic agents- Prochlorperazine (Compazine)
- Dimenhydrinate (Dramamine)
- Metoclopramide (Reglan)
 
- Consider specific agents- Chemotherapy-Induced Vomiting (see below)
- Anxiety related Nausea: Benzodiazepines, Cannabinoids
- Bowel Obstruction: Octreotide
- Gastroparesis: Metoclopramide
- Increased Intracranial Pressure: Dexamethasone
- Opioid-related bowel dysfunction: Methylnaltrexone
 
- Refractory Nausea- Combine 2-3 drugs from above
- Consider Haloperidol (Haldol)- Start at 0.5 to 2 mg PO IV or SC q6 hours
- Titrate to 10 to 15 mg total daily dose
 
- Consider adding Prednisone or Dexamethasone
- Consider Cannabinoids
 
- 
                          Emesis continues- Consider Rectal route (e.g. Compazine)
- Consider Subcutaneous Route (e.g. Haldol)
- Consider Transdermal route (e.g. Scopolamine)
 
- Other cause specific management- See Cancer Related Bowel Obstruction
- Anxiety: Benzodiazepines or Cannabinoids
- Gastroparesis: Metoclopramide (Reglan)
- Increased Intracranial Pressure: Dexamethasone
- Medication related- See Chemotherapy related Nausea treatment as above
- See Opioid Adverse Effect Management for Opioid-Induced Nausea
 
 
- Other medication selection precautions- Comorbid Delirium
- Dry Mouth (Xerostomia)- Avoid orally disintegrating tablets (requires Saliva to dissolve tablet)
 
 
VII. Management: Chemotherapy-Induced Vomiting
- Background- Regimens are started before Chemotherapy and continued for 3 days after
- Typical dosing 30 minutes before Chemotherapy- Ondansetron 16 to 32 mg IV or 24 mg orally (or other 5-HT3 Antagonist) AND
- Dexamethasone 4 mg (often 20 mg orally daily given)
 
- 5-HT3 Antagonists used in Chemotherapy induced Vomiting
 
- 
                          Chemotherapy with the strongest emetic effects (e.g. Cisplatin)- Ondansetron (or other 5-HT3 Antagonist) AND
- Dexamethasone AND
- Aprepitant (or Zyprexa)- Akynzeo (Palonosetron and Netupitant) may be used as a single dose prior to Chemotherapy
- Akynzeo lasts for 3 days and can be used in place of Aprepitant and Ondansetron
 
 
- 
                          Chemotherapy with the moderate emetic effects (e.g. Oxaliplatin)- Ondansetron (or other 5-HT3 Antagonist) AND
- Dexamethasone
- Consider adding Aprepitant (or Zyprexa) if needed
 
- 
                          Chemotherapy with the lower emetic effects (e.g. Paclitaxel)- Dexamethasone (e.g. 20 mg orally) for a single dose prior to Chemotherapy
- Alternatives to Dexamethasone
 
- Delayed Chemotherapy-Induced Nausea- Metoclopramide (Reglan) 1-2 mg IV or orally every 2-4 hours AND
- Dexamethasone 4 mg
 
- References- (2014) Presc Lett 21(12): 71
 
VIII. Preparations: Antiemetics
- 
                          Anticholinergics- Consider in excess oral secretions
- Scopolamine (Transdermal 1.5 mg patch) 1-2 patches replaced every 48 to 72 hours
 
- 
                          Phenothiazines- Prochlorperazine (Compazine) 5-10 mg PO or IV every 6-8 hours or 25 mg rectally every 12 hours
- Promethazine (Phenergan) 25-50 mg orally, rectally or IV every 6 hours- Overused, sedating and relatively ineffective in Palliative Care
 
- Chlorpromazine (Thorazine) 12.5 to 25 mg IV every 6-8 hours or 25-50 mg orally every 8 hours
 
- Butyrophenones- Haloperidol (Haldol) 0.5 to 2 mg orally or IV every 4-8 hours
- Droperidol (Inapsine) 1.25 to 2.5 mg IV- Strong black box warning in U.S. due to risk of QT Prolongation, but appears safe
- Calver (2015) Ann Emerg Med 66(3): 230-8 +PMID:25890395 [PubMed]
 
 
- Thienobenzodiazepine- Olanzapine (Zyprexa)- Often dosed prophylactically at night (e.g. 2.5 mg ODT before bedtime)
 
 
- Olanzapine (Zyprexa)
- 
                          Antihistamines- Meclizine (Antivert)- Indicated for vestibular associated Emesis
 
- Diphenhydramine (Benadryl) 12.5 to 50 mg orally, rectally, or IV every 4-12 hours
- Hydroxyzine (Atarax, Vistaril)
 
- Meclizine (Antivert)
- Gastrokinetic agents- Consider in Gastroparesis, but avoid in suspected malignant Small Bowel Obstruction
- Metoclopramide (Reglan) 5-20 mg orally or IV every 6 hours
 
- 
                          5-HT3 Receptor Antagonists- Ondansetron (Zofran) 4-8 mg orally (esp. ODT dissolvable) or IV every 4-8 hours
- Granisetron (Kytril) 1 mg orally or IV twice daily
- Dolasetron (Anzemet)
 
- 
                          Cannabinoids- Consider in anticipatory Nausea
- Nabilone (Cesamet) 1-2 mg orally every 12 hours
- Dronabinol (Marinol) 5-10 mg orally, rectally or sublingual every 6-8 hours
 
- 
                          Corticosteroids- Consider in malignant Small Bowel Obstruction or Increased Intracranial Pressure
- Dexamethasone (Decadron) 2-8 mg orally or IV every 4-8 hours
 
- Benzodiazepines
 
          