Nausea%20-and-%20vomiting Treatment

• The underlying cause of nausea and vomiting should be identified and treated properly
• In patients for whom the primary cause of nausea and vomiting cannot be found easily, treatment should be directed at reduction or elimination of symptoms
• Oral and IV antiemetic formulations have equivalent effectiveness when used at appropriate doses
• The lowest, maximally effective dose of antiemetic should be used
• The toxicity profile of antiemetic agents should be taken into consideration
  
  • For multidrug regimens, choice of antiemetic therapy will depend on the drug with the greatest emetic risk
  • For multiple-day chemotherapy, choice of antiemetic therapy will be based on the emetic risk of the antineoplastic agent given on each day of the treatment and for 2 days following completion of therapy
• For women suffering from nausea and vomiting of pregnancy, the severity of symptoms and the patient’s desire for treatment are important considerations in making treatment decisions
  • It is recommended to initiate treatment early to prevent progression to hyperemesis gravidarum
• Hospitalization is indicated if patient experiences weight loss and changes in mental status or vital signs and is unresponsive to outpatient management

Chemotherapy-Related Nausea and Vomiting

• The goal of treatment is to prevent nausea and vomiting
  
  • Generally, antiemetic treatment should be started prior chemotherapy to maximally protect against nausea and vomiting
• The choice of antiemetic agent should be based on the emetogenic potential of a patient’s chemotherapy regimen as well as patient factors and previous experience with antiemetic therapy
  • Patient receiving concurrent chemoradiotherapy should be given antiemetics based on the emetic risk of the chemotherapeutic agent unless the risk of nausea and vomiting is higher from radiotherapy in which case the antiemetics will be based on the radiotherapy emetic risk level
• Patients receiving chemotherapy are at risk of chemotherapy-related nausea and vomiting for at least 2-3 days after chemotherapy administration and should be protected for this whole duration

Antihistamines 

• Nausea and vomiting of a labyrinthine origin eg motion sickness, migraine and vertigo may be treated with antihistamines
• Part of the 1st-line treatment for nausea and vomiting of pregnancy
  
  • Antihistamines that are considered safe in pregnancy: Cyclizine, Dimenhydrinate, Diphenhydramine, Doxylamine, Hydroxyzine, Meclizine, Promethazine
• Also useful for acute or breakthrough episodes of nausea and vomiting of pregnancy because of the availability of parenteral and suppository forms
• May also be given to patients with PONV
• Action: Act as histamine-1 receptor antagonists and exert a central antiemetic effect

Benzodiazepines

• Alprazolam and Lorazepam may be used as adjunctive components of antiemetic regimens for prevention of chemotherapy-related nausea and vomiting (not to be used as single-agent antiemetics), ie anticipatory chemotherapy-related nausea and vomiting or breakthrough chemotherapy-related nausea and vomiting with anxiety component

Butyrophenones

• Eg Droperidol, Haloperidol
• May be used for PONV and anticipatory and acute chemotherapy-related nausea and vomiting
• Haloperidol is an alternative option to Metoclopramide in patients with advanced cancer 
• Action: Probably exert a central antidopaminergic effect

Corticosteroids

• Eg Dexamethasone, Methylprednisolone, Prednisolone
• Used in combination with other antiemetic medications in the treatment of chemotherapy-related nausea and vomiting
  • Given to patients with known potential for delayed emesis after receiving moderately emetogenic chemotherapy
  • May be used to prevent emesis of chemotherapeutic agents of low risk
• Dexamethasone may be used alone or in combination with other antiemetic agents for prevention of PONV
  • Course of delayed Dexamethasone may be extended as clinically appropriate for patients experiencing extended delayed chemotherapy-related nausea and vomiting
• Methylprednisolone may be used as a last resort in nausea and vomiting of pregnancy in patients who require enteral or parenteral nutrition because of weight loss
  • Avoid use during the 1st trimester because of possible risk of oral clefting
• Action: Effect may be due to reduction of prostaglandin formation

Neurokinin-1 (NK-1) Receptor Antagonists

• Eg Aprepitant, Fosaprepitant, Netupitant, Fosnetupitant, Rolapitant, Vestipitant 
• Used in combination with other antiemetic agents for prevention of acute and delayed chemotherapy-related nausea and vomiting
• Complements the antiemetic action of other available agents
  
  • Enhances the antiemetic activity of the serotonin 5-HT₃ antagonists and Dexamethasone in inhibiting acute and delayed Cisplatin-induced vomiting
• Netupitant combined with Palonosetron is approved for prevention of nausea and vomiting in highly and moderately emetogenic chemotherapy regimens
  • This combination together with Dexamethasone is recommended for prevention of acute and delayed emesis
• May also be useful prophylactic agents for highly undesirable postoperative emesis, eg gastric and neurosurgery
• Action: Selectively blocks the binding of substance P at the NK-1 receptor in the CNS

Phenothiazines

• Commonly used for severe attacks of nausea and vomiting, including nausea and vomiting associated with vertigo, migraine and motion sickness
• Availability in various formulations is useful for patients who cannot tolerate oral medications
• May be given as 2nd-line treatment for nausea and vomiting of pregnancy and are usually employed in severe cases
  
  • Chlorpromazine, Perphenazine, Prochlorperazine, Promethazine, Trifluoperazine are considered safe to use in pregnancy
• Perphenazine is suggested by limited data to be effective for PONV prophylaxis without increasing sedation or drowsiness 
• Levomepromazine is an alternative option to Metoclopramide in patients with advanced cancer 
• Action: Exert a central antidopaminergic effect in the area postrema of the brain

Prokinetic Agents

• Eg Domperidone and Metoclopramide
• Mainly used in gastroparesis and other dysmotility syndromes
• May be used to prevent delayed chemotherapy-related emesis
• Metoclopramide is the drug of choice in patients with advanced cancer
  • Given as needed to patients treated with oral anticancer agents with low to minimal emetic risk 
  • Considered safe to use in pregnancy and is considered a 2nd-line agent
  • May be considered an alternative agent for PONV if other antidopaminergics are not available
• Treatment should be at the lowest effective dose and kept as short as possible, ie up to 5 days (not to exceed 12 weeks), to reduce the risks of neurological, cardiac and other adverse effects
• Action: Exert an antidopaminergic effect and appear to have some direct and indirect anticholinergic effects
  
  • Exert prokinetic effects on the esophagus, stomach and upper small intestine

Serotonin 5-HT₃ Antagonists

• Eg Dolasetron, Granisetron, Ondansetron, Palonosetron, Ramosetron, Tropisetron
• Used for prevention of acute chemotherapy-related nausea and vomiting and both oral and IV forms are equally effective at appropriate doses and intervals
  
  • Palonosetron has been shown to be effective as prophylaxis for both delayed and acute chemotherapy-related emesis
• May also be used alone or in combination with Dexamethasone for prevention of PONV
• Optimal effects can be seen with scheduled dosing and not as needed
• There is limited data on the safety of serotonin 5-HT₃ antagonists in pregnancy
  
  • Use should be restricted to treatment of refractory nausea and vomiting when other agents that have established safety and efficacy have failed
  • Ondansetron at 8 mg PO 12 hourly, 8 mg IV 12 hourly, or 1 mg/hr IV infusion x 24 hours has been given
• Action: Primary site of action of these drugs is thought to be on the chemoreceptor trigger zone in the area postrema of the brain where the highest concentration of 5-HT₃ receptors are found

Vitamin Supplementation

Pyridoxine (Vit B₆)

• Has been shown to be safe and effective in treating nausea and vomiting of pregnancy
  
  • May be more effective in reducing nausea than vomiting
• May be given as monotherapy or combined with antihistamines, eg Doxylamine

Other Agents

• Ephedrine, gabapentinoids (eg Gabapentin, Pregabalin), Midazolam and low-dose Naloxone infusion are other antiemetics that can be used for PONV  

Cannabinoids 

• US FDA-approved cannabinoids (Dronabinol or Nabilone) may be used to treat nausea and vomiting that is resistant to standard antiemetic therapies; evidence is still limited to recommend medical marijuana for either prevention or treatment of chemotherapy- and radiation-related nausea and vomiting
• Start with lower doses then titrate upwards to lessen hallucinations or paranoia

Ginger Root

• Has been shown to be effective for nausea and vomiting of pregnancy
• Caution should be exercised when prescribing ginger because there may be variabilities between available preparations
• Safety data is lacking, though many cultures use ginger as a spice with amounts similar to commonly prescribed therapy

Olanzapine

• An atypical antipsychotic agent which is also used as an antiemetic agent
• Both 3- and 4-drug Olanzapine-containing antiemetic regimens are effective in preventing acute and delayed emesis in highly and moderately emetogenic chemotherapy 
• Can be used as an alternative agent for patients who are intolerant of Dexamethasone
• Use with caution in patients at risk for orthostatic hypotension or for falls; monitor patients for excessive sedation and dystonic reactions

Rehydration

• Patients with nausea and vomiting may become dehydrated and malnourished because of inadequate oral intake of fluid and nutrients, including electrolytes
  • Fluids and electrolytes, notably potassium, are lost directly in the vomitus
• Patients’ fluid and electrolyte status should be properly assessed to ensure adequate replacement
• Use IV hydration in patients with signs of dehydration or if unable to tolerate oral liquids 
  • Normal saline solutions are commonly used, together with potassium supplementation as needed
• In patients with gastric distension, a nasogastric tube may have to be inserted and tube output measured so that appropriate replacement may be given
• No study has compared the different fluid replacements for nausea and vomiting of pregnancy