Nausea & Vomiting Management

Last updated: 06 October 2025
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Principles of Therapy

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 intravenous 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 also be taken into consideration. For multidrug regimens, the choice of antiemetic therapy will depend on the drug with the greatest emetic risk. For multiple-day chemotherapy, the 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 the 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 to 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. Patients 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. Consider an H2 blocker or a proton pump inhibitor (PPI) to prevent dyspepsia.

Pharmacological therapy

Antihistamines

Nausea and vomiting of a labyrinthine origin (eg motion sickness, migraine and vertigo) may be treated with antihistamines. Antihistamines are a part of the first-line treatment for nausea and vomiting of pregnancy. Antihistamines that are considered safe in pregnancy are Cinnarizine, Cyclizine, Dimenhydrinate, Diphenhydramine, Doxylamine, Hydroxyzine, Meclizine, and Promethazine. These are also useful for acute or breakthrough episodes of nausea and vomiting of pregnancy because of the availability of parenteral and suppository forms. These may also be given to patients with postoperative nausea and vomiting. These act as histamine-1 receptor antagonists and exert a central antiemetic effect.

Benzodiazepines



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Alprazolam and Lorazepam may be used as adjunctive components of antiemetic regimens for the 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 an anxiety component. Use with caution in patients treated with opioids due to increased risk of respiratory depression.

Butyrophenones

Example drugs: Droperidol, Haloperidol

Butyrophenones may be used for postoperative nausea and vomiting and anticipatory and acute chemotherapy-related nausea and vomiting. Reserve Droperidol for patients who fail to show an acceptable response to other adequate therapies. Haloperidol is an alternative option to Metoclopramide in patients with advanced cancer. Lower doses of Haloperidol are sufficient for antiemesis compared to those required for antipsychosis. These probably exert a central antidopaminergic effect.

Corticosteroids

Example drugs: Dexamethasone, Methylprednisolone, Prednisolone 



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Corticosteroids are used in combination with other antiemetic medications in the treatment of chemotherapy-related nausea and vomiting. These are given to patients with known potential for delayed emesis after receiving moderately emetogenic chemotherapy. These 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 postoperative nausea and vomiting. A 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 first trimester because of the possible risk of oral clefting. The effect may be due to reduction of prostaglandin formation.

Neurokinin-1 (NK-1) Receptor Antagonists

Example drugs: Aprepitant, Fosaprepitant, Fosnetupitant, Netupitant, Rolapitant, Vestipitant

Neurokinin-1 (NK-1) receptor antagonists are used in combination with other antiemetic agents for prevention of acute and delayed chemotherapy-related nausea and vomiting, with the largest benefit seen in delayed chemotherapy-related nausea and vomiting. These complement the antiemetic action of other available agents. These enhance the antiemetic activity of the 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. These may also be useful prophylactic agents for highly undesirable postoperative emesis, eg gastric and neurosurgery. These selectively block the binding of substance P at the NK-1 receptor in the central nervous system.

Phenothiazines

Phenothiazines are 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. This may be given as second-line treatment for nausea and vomiting of pregnancy and is usually employed in severe cases. Chlorpromazine, Perphenazine, Prochlorperazine, Promethazine, Trifluoperazine are considered safe to use in pregnancy. Promethazine has more histamine blockade than Prochlorperazine resulting in greater sedation. Perphenazine is suggested by limited data to be effective for postoperative nausea and vomiting prophylaxis without increasing sedation or drowsiness. Levomepromazine is an alternative option to Metoclopramide in patients with advanced cancer. These exert a central antidopaminergic effect in the area postrema of the brain.

Prokinetic Agents

Example drugs: Domperidone, Metoclopramide

Prokinetic agents are mainly used in gastroparesis and other dysmotility syndromes. These may be used to prevent delayed chemotherapy-related emesis. Metoclopramide is the drug of choice in patients with advanced cancer. This is given as needed to patients treated with oral anticancer agents with low to minimal emetic risk. This is considered safe to use in pregnancy and is considered a second-line agent. This may be considered an alternative agent for postoperative nausea and vomiting 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. Prokinetic agents exert an antidopaminergic effect and appear to have some direct and indirect anticholinergic effects. These also exert prokinetic effects on the esophagus, stomach, and upper small intestine.

Serotonin (5-HT3) Antagonists

Example drugs: Dolasetron, Granisetron, Ondansetron, Palonosetron, Ramosetron, Tropisetron

Serotonin (5-HT3) antagonists are used for the 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. These may also be used alone or in combination with Dexamethasone for prevention of PONV. Optimal effects can be seen with scheduled dosing and not with as-needed use. There is limited data on the safety of 5-HT3 antagonists in pregnancy. The 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. The 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 is found.

Vitamin Supplementation

Pyridoxine (Vitamin B6) 



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Pyridoxine has been shown to be safe and effective in treating nausea and vomiting of pregnancy. This may be more effective in reducing nausea than vomiting and 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 postoperative nausea and vomiting.

Cannabinoids

US FDA-approved cannabinoids (eg Dronabinol or Nabilone) may be used to treat nausea and vomiting that are 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 minimize adverse effects (eg hallucinations, paranoia).

Ginger Root

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 in amounts similar to commonly prescribed therapy.

Hyoscine (Scopolamine)

Hyoscine may be considered when nausea or vomiting is precipitated by positional changes, movement, or excessive secretions.

Olanzapine

Olanzapine is an atypical antipsychotic agent that is also used as an antiemetic agent. Both three- and four-drug Olanzapine-containing antiemetic regimens are effective in preventing acute and delayed emesis in highly and moderately emetogenic chemotherapy. This 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 and monitor patients for excessive sedation and dystonic reactions. 

Nonpharmacological

Rehydration



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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 intravenous hydration in patients with signs of dehydration or if they are 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.

Dietary Modification and Supportive Measures

Dietary Modifications

Intake of food and fluids should be frequent, in small amounts, and at room temperature. Spicy or fatty foods and cold, sweet, tart, or carbonated beverages should be avoided. Indigestible or partially digestible material should be avoided.

Nausea and Vomiting of Pregnancy

Encourage vitamin supplementation, particularly Folic acid, for pregnant women. Prenatal vitamins may be taken a month prior to pregnancy to decrease the incidence and severity of nausea and vomiting. Protein-rich meals may be preferable for alleviating symptoms compared to carbohydrate- or fat-rich meals. Crackers and dry or bland foods may be taken in the morning before getting up. Enteral nutrition should be considered in the dehydrated patient or those with significant or persistent weight loss who are unresponsive to antiemetics. Parenteral nutrition can be given to pregnant women who are unable to tolerate enteral feeding. Intravenous Thiamine initially with the rehydration fluid, then daily for 2-3 days, followed by IV multivitamin or as per local protocol, should be considered in women who require IV hydration and who have vomited for >3 weeks.

Supportive Measures 



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Behavioral therapy options for anticipatory nausea and vomiting include yoga, cognitive distraction, biofeedback, and relaxation exercises. Other measures to reduce nausea and vomiting may be useful, particularly in patients who have nausea and vomiting of pregnancy. Patients should be advised to increase their rest because tiredness may make nausea worse. Advise patients to avoid sensory stimuli that trigger symptoms (eg strong odors, noise, flickering lights, heat, and humidity). Enlist support from the patient's family and friends. Acupressure, acupuncture, and acustimulation may be beneficial in patients with postoperative nausea and vomiting and in women with nausea and vomiting of pregnancy.