Assessment of the emetogenic potential of intrathecal chemotherapy and response to prophylactic treatment with ondansetron

 The purpose of this study was to document the emetogenic potential of intrathecal chemotherapy (IC) in children and to evaluate the efficacy of ondansetron in reducing nausea and vomiting with this chemotherapy treatment. Patients less than 18 years of age with acute lymphoblastic leukemia were eligible to participate in a survey project measuring the emetogenic potential of various chemotherapy treatments. Patients surveyed for 1 or more IC treatments were included in this report. The IC consisted of methotrexate, hydrocortisone and cytarabine, dosed according to patient age. A nausea/vomiting survey instrument was completed by each patient and/or parent following IC treatment. The instrument rated nausea, vomiting and daily activity interference (DAI) on a 4-point scale of 0=none, 1=mild, 2=moderate and 3=severe, and collected data on the number of vomiting and/or retching episodes in addition to the child's appetite following the chemotherapy treatment. When ondansetron was employed, it was administered in an i.v. infusion at a dose of 0.15 mg/kg before and after chemotherapy or as an oral dose of 4 mg or 8 mg before chemotherapy. Courses of IC without antiemetics were analyzed to determine the emetogenic potential of IC. For patients receiving IC both with and without ondansetron, courses were compared with each patient used as their own control to determine the influence of ondansetron upon survey responses. Statistical analysis consisted of nonparametric Friedman 2-way ANOVA for ordinal variables and a paired t-test for continuous variables. The binomial test was employed to analyze for differences between ondansetron and no antiemetic in the number of patients with complete control of both nausea and vomiting or vomiting alone. A total of 63 children with a mean age of 7.6±4.2 years were each studied on one or more occasions. Thirty-seven children were surveyed for 87 IC treatments without antiemetics (group I), and 17 children from this group were surveyed for 48 IC courses with i.v. ondansetron (group IA). An additional 18 children were subsequently surveyed for 39 IC courses with i.v. ondansetron (group II). Fifteen patients (7 of whom were members of group I) were surveyed following 33 IC courses with oral ondansetron (group III). The survey scores for group I patients were: nausea severity 1.3±1.1, vomiting severity 1.2±1.1, DAI 1.2±1.0 and mean number of emetic episodes 4.7±8.4. The mean appetite score was 1.5±1.1. For patients in group IA, nausea severity (0.8±0.9), vomiting severity (0.5±0.8), DAI (0.7±0.8), and the number of emetic episodes (1.4±2.8) were all significantly lower than with prior IC treatments without ondansetron. For complete protection, children receiving i.v. ondansetron had greater complete protection rates from both nausea and vomiting or vomiting alone than did patients receiving no antiemetic. Survey responses were also lower for patients receiving oral ondansetron, but insufficient control data did not allow for statistical analysis. IC results in mild to moderate nausea and vomiting in children. The emetogenic potential of IC is significantly reduced by i.v. ondansetron.     

Granisetron plus dexamethasone in moderately emetogenic chemotherapy: evaluation of activity during three consecutive courses of chemotherapy

In this study we evaluated the antiemetic activity of a combination of 3 mg granisetron in a short i.v. infusion followed by 12 mg dexamethasone i.v. in 64 patients with cancer receiving moderately emetogenic chemotherapy scheduled in a single day. No patient had previously undergone chemotherapy and three consecutive cycles were evaluated. Response to antiemetic treatment was graded as follows: complete response, no episodes of vomiting; major response, only one episode; minor response, two to four episodes; failure, more than four episodes. Nausea was graded as absent, mild, moderate or severe (patients bedridden). At the first cycle a complete protection from acute vomiting and nausea was achieved in 95% and 73% of patients respectively; the rate of complete response for delayed vomiting was 90%, while 45% of patients complained of delayed nausea. The antiemetic and antinausea efficacy remained substantially unchanged during the second and third cycles of chemotherapy. Constipation and headache were the most frequent adverse events. In conclusion this antiemetic regimen appears very effective in preventing nausea and vomiting in moderately emetogenic chemotherapy.     

A double-blind,crossover, randomized dose-comparison trial of granisetron for the prevention of acute and delayed nausea and emesis in children receiving moderately emetogenic carboplatin-based chemotherapy

Background Granisetron is a safe and effective prophylaxis for nausea and vomiting associated with moderate to highly emetogenic chemotherapy. Few trials have been conducted to determine the optimal effective dose of granisetron in children with cancer. The objective of this report was to compare two doses of granisetron in patients with optic pathway tumors receiving moderately emetogenic doses of carboplatin. Patients and methods In this double-blind, crossover, randomized study, antiemetic efficacy and tolerability of two dose levels (10 and 40 μg/kg) of granisetron in the prevention of acute and delayed nausea/emesis were compared in children and young adults. A total of 18 patients (13 boys) aged 1–23 years (median 7.7 years) treated with a moderately emetogenic dose of carboplatin were randomly assigned to receive either 10 or 40 μg/kg of slow granisetron intravenous (i.v.) infusions at alternating cycles of chemotherapy in a blinded fashion until the end of the study period or until their chemotherapy regimen ended. In this way, the patients acted as their own controls. Results Patients in the granisetron 10 and 40 μg/kg groups received 104 and 121 cycles of chemotherapy, respectively. There was no significant difference in antiemetic efficacy in terms of nausea and emesis between the dose groups in the first 5 days of chemotherapy. The treatment was well tolerated. Conclusion We conclude that granisetron 10 and 40 μg/kg have comparable efficacy in controlling carboplatin-induced acute and delayed nausea/emesis and is well tolerated in children and young adults.     

Acupuncture against chemotherapy-induced nausea and vomiting in pediatric oncology

GOALS: In this multicenter crossover study, our aim was to evaluate the efficacy and acceptance of acupuncture as a supportive antiemetic approach during highly emetogenic chemotherapy in pediatric oncology. PATIENTS AND METHODS: Eleven children receiving several courses of highly emetogenic chemotherapy for treatment of solid tumors were included. Randomization allocated patients to start chemotherapy either with antiemetic medication plus acupuncture or antiemetic medication alone. During all study courses, patients continued to receive their programmed and additional antiemetic medication as needed. Acupuncture was given at day 1 of chemotherapy and at subsequent days on patient's demand. The amount of baseline and additional antiemetic medication during chemotherapy was documented. Patients maintained a daily diary of vomiting episodes and completed an evaluated nausea score at the end of every course. Their body weight was taken before and after a chemotherapy course. MAIN RESULTS: Twenty-two courses with or without acupuncture were compared. The benefits of acupuncture in adolescents with respect to the reduction of additional antiemetic medication were observed. Acupuncture enabled patients to experience higher levels of alertness during chemotherapy and reduced nausea and vomiting. Except for needle pain, no side effects were noted. Patient's acceptance of acupuncture was high. CONCLUSION: Our data indicate that acupuncture might reduce antiemetic medication and episodes of vomiting in pediatric oncology.     

Antiemetic activity of megestrol acetate in patients receiving chemotherapy

Purpose

Several trials had independently noted that patients receiving megestrol acetate had less nausea and vomiting, but this antiemetic activity of megestrol acetate has not been reported separately in the literature. Our objective was to evaluate the antiemetic ability of megestrol acetate in patients receiving chemotherapy.

Patients and Methods

Patients receiving chemotherapy were randomly assigned to receive either megestrol acetate 320?mg PO or placebo before the first day of chemotherapy, followed on days 1?C4 by megestrol acetate 320?mg PO combined with granisetron 3?mg IV and metoclopramide 20?mg IM or only granisetron 3?mg IV combined with metoclopramide 20?mg IM in a crossover manner during two consecutive cycles. Rates of complete protection against both vomiting and moderate-to-severe nausea was the primary end point.

Results

One hundred patients were enrolled in the study. The antiemetic regimen containing megestrol acetate was superior in providing complete protection from nausea and vomiting (45% megestrol acetate regimen vs.17% no megestrol acetate regimen). Complete response of acute phase in both antiemetic regimens was different (85% megestrol acetate regimen vs. 72% no megestrol acetate regimen). Complete response of delayed emesis was also different (49% megestrol acetate regimen vs. 18% no megestrol acetate regimen). Adverse events were mostly mild to moderate. There were no serious drug-related adverse events between the two antiemetic regimens.

Conclusion

Megestrol acetate was shown to be an effective antiemetic agent. Megestrol acetate might be a new antiemetic option for chemotherapy.     

Delayed emesis: incidence, pattern, prognostic factors and optimal treatment

Delayed emesis has been arbitrarily defined as vomiting and/or nausea beginning, or persisting for, more than 24 h after chemotherapy administration. Acute emesis is the most important prognostic factor for delayed emesis. Owing to the relatively high incidence and severity all patients treated with cisplatin > or = 50 mg/m(2) should receive antiemetic prophylaxis. In these patients a combination of dexamethasone plus metoclopramide or a 5-HT3 antagonist is the most efficacious regimen. All patients submitted to moderately emetogenic chemotherapy, such as cyclophosphamide, carboplatin, doxorubicin and epirubicin, should also receive antiemetic prophylaxis with oral dexamethasone to prevent delayed emesis.     

Effectiveness of a single-day three-drug regimen of dexamethasone, palonosetron, and aprepitant for the prevention of acute and delayed nausea and vomiting caused by moderately emetogenic chemotherapy

Purpose

Chemotherapy-induced nausea and vomiting includes both Acute (0–24 h) and Delayed (24–120 h) components with different physiologic mechanisms. A combination of a serotonin antagonist, a corticosteroid, and an NK-1 antagonist has proven effective against this problem. However, standard antiemetic regimens require administration over 3–4 days after chemotherapy. The present study evaluated a more convenient single-day three-drug antiemetic regimen for patients receiving moderately emetogenic chemotherapy.

Materials and methods

Chemotherapy-naïve patients with solid tumors receiving cyclophosphamide and/or doxorubicin were eligible. Patients could not have pre-existing etiologies for vomiting. Prior to chemotherapy, patients received a single dose of aprepitant 285 mg p.o., dexamethasone 20 mg p.o., and palonosetron 0.25 mg i.v. A daily patient diary recording episodes of emesis and severity of nausea was then kept for 5 days. Any further antiemetics were considered rescue medication.

Results

Forty-one eligible and evaluable patients (40 women, one man) with breast cancer were entered on study. Most were receiving adjuvant chemotherapy. Complete Response (no vomiting, no rescue medication) was seen in 51% of patients, including 76% with Complete Response for the Acute period and 66% for the Delayed period. No emesis was reported for 100% of patients in the Acute period and 95% in the Delayed period. No Nausea was seen in 32% of patients. No untoward toxicities were seen.

Conclusion

A single-day three-drug antiemetic regimen is feasible and effective for protection against both Acute and Delayed vomiting after moderately emetogenic chemotherapy. Formal comparison to a standard multi-day antiemetic regimen is warranted.     

Comparison of patient-controlled and nurse-controlled antiemetic therapy in patients receiving chemotherapy

The purpose of this quasi-experimental pilot study was to compare the effect of patient-controlled (PCAE) and nurse administered (NCAE) antiemetic therapy for controlling chemotherapy-induced nausea and vomiting in patients receiving moderate emetogenic chemotherapy. Twenty subjects were randomly assigned to either the PCAE group who received IV antiemetic medication via a patient-controlled pump or the NCAE group who received antiemetic medication via nurse administered minibags. Nausea, vomiting, sedation, and drug consumption were measured. There was no difference in nausea scores between the two groups. Subjects in the PCAE group consumed significantly less medication than subjects in the NCAE group.     

Radiotherapy-induced nausea and vomiting (RINV): antiemetic guidelines

As many as 40–80% of patients undergoing radiotherapy (RT) will experience nausea and/or vomiting, depending on the site of irradiation. Fractionated RT may involve up to 40 fractions over a 6–8 weeks period, and prolonged symptoms of nausea and vomiting could affect quality of life. Furthermore, uncontrolled nausea and vomiting may result in patients delaying or refusing further radiotherapy. Nausea and vomiting are often underestimated by radiation oncologists. Incidence and severity of nausea and vomiting depend on RT-related factors (single and total dose, fractionation, irradiated volume, radiotherapy techniques) and patient-related factors (gender, general health of the patient, age, concurrent or recent chemotherapy, psychological state, tumor stage). Current antiemetic guidelines prescribe the emetogenicity of radiotherapy regimens and recommend the use of 5-HT₃ antagonists with or without a steroid for prophylaxis in moderately and highly emetogenic treatment (MASCC, ASCO, ASHP, NCCN). The new proposed guidelines summarise the updated data from the literature and take into consideration the existing guidelines. According to the irradiated area (the most frequently studied risk factor), the proposed guidelines are divided into four levels of emetogenic risk: high, moderate, low and minimal. They offer guidance to prescribing physicians for effective antiemetic therapies in RINV.Perugia Antiemetic Consensus Conference 2004.     

Aprepitant for chemotherapy-induced nausea and vomiting

Although the development of serotonin receptor antagonists has greatly improved treatment for chemotherapy-induced nausea and vomiting, patients receiving chemotherapy continue to experience this troublesome side effect. On March 26, 2003, the U.S. Food and Drug Administration approved aprepitant (Emend, Merck & Co., Inc., Whitehouse Station, NJ) for use in combination with standard antiemetic agents for acute and delayed nausea and vomiting with initial and repeat courses of highly emetogenic therapy. Aprepitant appears to provide superior control of acute and delayed emesis compared to standard antiemetic therapy. Aprepitant was well tolerated in phase III studies, with side effects similar to standard therapy. Healthcare providers need to be aware of potential drug interactions with aprepitant. Oncology nurses continue to play a key role in helping patients adhere to their antiemetic schedules, stressing the importance of prevention of nausea and vomiting.     

Closing the gap in prophylactic antiemetic therapy: patient factors in calculating the emetogenic potential of chemotherapy

The ability to provoke emesis is defined by the emetogenic potential of each antineoplastic agent and by individual prognostic factors that determine the risk for each patient. The risk of chemotherapy-induced emesis is increased for females, patients between the ages of 6 and 50, and patients who drink little or no alcohol. Other risk factors include susceptibility to motion sickness and high levels of anxiety. Patients with one or more risk factors may require antiemetic treatment typically prescribed for a highly emetogenic regimen, even when a chemotherapy regimen is considered moderately emetogenic. The 5-HT3 receptor antagonists are the most effective agents against chemotherapy-induced nausea and should become standard antiemetic therapy for high-risk patients. Knowledge of factors affecting emesis and the antiemetic agents available for treating high-risk patients are the keys to successful nursing management of emesis in patients receiving chemotherapy.     

Superiority of methylprednisolone sodium succinate over low dose metoclopramide hydrochloride in the prevention of nausea and vomiting produced by cancer chemotherapy

Methylprednisolone sodium succinate and metoclopramide were compared for their efficacy, tolerance, and safety in the prevention of nausea and vomiting induced by moderately emetogenic chemotherapy in patients with cancer. Previously untreated patients about to receive at least 2 cycles of identical chemotherapy were entered into a study using a randomized, double-blind, crossover design. Patients were given either 250 mg of methylprednisolone or 10 mg of metoclopramide intravenously before the first cycle of chemotherapy and were then crossed over to receive the alternate medication before the second cycle of chemotherapy. Prochlorperazine was prescribed in both cycles for postchemotherapy nausea and vomiting. After each treatment cycle patients recorded the degree of nausea, drowsiness and anxiety, the number of episodes of vomiting experienced, and the amount of prochlorperazine taken. After the second treatment cycle patients recorded their preference for either the first or the second antiemetic medication with respect to nausea, vomiting, and overall effectiveness. Of 157 patients entered into the study, 115 were fully appraisable. Methylprednisolone was superior to metoclopramide in preventing nausea and vomiting and in decreasing anxiety and the amount of prochlorperazine used. A majority of the patients expressing a preference preferred methylprednisolone to metoclopramide for control of nausea (p = 0.003), control of vomiting (p = 0.0006), and overall effectiveness (p = 0.00004). There were few side-effects. We conclude that methylprednisolone may have some utility as an antiemetic in patients receiving moderately emetogenic chemotherapy, and who are treated as outpatients.     

AVASCULAR NECROSIS OF BONE: THE HIDDEN RISK OF GLUCOCORTICOIDS USED AS ANTIEMETICS IN CANCER CHEMOTHERAPY

The role of antiemetics is invaluable in allowing cancer patients to complete otherwise potentially intolerable chemotherapy. Corticosteroids have an established place in the prevention and treatment of nausea and vomiting due to emetogenic cytotoxic agents. Avascular necrosis of bone is a recognised complication of glucocorticoid treatment – the risk of this increasing with higher doses and longer duration of use. This report details a case of bilateral avascular necrosis of the femoral heads in a patient receiving ‘standard’ doses of dexamethasone as part of the antiemetic regimen used in cisplatin-based combination chemotherapy.     

Clinical roundtable monograph. The oncologist's role in management of venous thromboembolism

Chemotherapy-induced nausea and vomiting (CINV) is one of the most common and troubling side effects of treatment, and the side effect cancer patients tend to fear most. An improved understanding of the pathophysiology underlying CINV, together with a clear definition of the risk for nausea and vomiting associated with specific chemotherapeutic agents, has for allowed the development of specific and effective antiemetic regimens. Anti-emesis is most effective when used prophylactically, a principle shared among CINV management guidelines. Several antiemetic drug classes are available; among the most effective of these are serotonin (5HT?) receptor antagonists, neurokinin 1 (NK?) receptor antagonists, and steroids (primarily dexamethasone), although others are commonly used as well. When choosing an appropriate antiemetic regimen, clinicians should consider patient-specific factors such as sex and prior history of CINV, as well as treatment-specific factors such as the emetogenic potential of each chemotherapeutic agent. Using these factors, clinicians can follow the available algorithms included in guidelines from groups such as the National Comprehensive Cancer Network, the American Society of Clinical Oncology, and the Multinational Association for Supportive Care in Cancer. Ongoing and future clinical trials will be pivotal in helping to further delineate the optimal strategies to prevent and manage CINV in cancer patients.     

Antiemetics in children receiving cancer chemotherapy

Nausea and vomiting are debilitating side effects that often accompany the administration of chemotherapy and may lead to adverse physiological and psychological effects. Chemotherapy agents usually stimulate the chemoreceptor trigger zone, which then sends signals to the vomiting center in the medullary lateral reticular formation. The neurochemistry of vomiting involves serotonin and serotonin S3 receptors. Nausea and vomiting are difficult to treat once they have occurred, and prior poor antiemetic control may lead to future anticipatory nausea and vomiting. Thus, good antiemetic regimens must be prophylactic, scheduled, and individualized. Specific regimens must be adjusted to account for the emetogenic potential of the chemotherapy drug(s) being administered and the individual patient's preferences. The major classes of antiemetics include serotonin S3 receptor antagonists, phenothiazines and metoclopramide. Steroids are ineffective antiemetics alone but good potentiators of other antiemetics. We usually recommend a serotonin S3 receptor antagonist alone for less emetogenic regimens or in conjunction with dexamethasone for more emetogenic regimens. For breakthough vomiting, we usually add lorazepam and/or scopolamine.Presented as an invited lecture at the 6th International Symposium: Supportive Care in Cancer, New Orleans, La., USA, 2–5 March 1994     

Randomized double-blind study of the Reliefband as an adjunct to standard antiemetics in patients receiving moderately-high to highly emetogenic chemotherapy

Goals Our goal was to evaluate the efficacy and tolerability of the Reliefband as an adjunct to standard antiemetics in patients receiving moderately-high to highly emetogenic chemotherapy.Patients and methods Forty-nine adult cancer patients receiving moderately-high or highly emetogenic chemotherapy were randomized to receive either the active Reliefband (n=26) or an inactive device (n=23). Patients continued to receive all scheduled and as needed antiemetic agents as prescribed. The device was worn the day of chemotherapy administration for 5 days (days 1–5). Patients maintained a daily dairy of nausea severity, vomiting and retching episodes, and antiemetic medications taken. Each patient completed a Functional Living Index Emesis (FLIE) and a tolerability survey at the conclusion of the study. A Wilcoxon rank sum test was used to compare the number of vomiting episodes, severity of nausea and FLIE scores between the two groups.Main results Patients wearing the active Relifband experienced less vomiting (Reliefband 1.9 versus inactive device 4.6 mean episodes; p=0.05), retching (1.4 versus 3.6 mean episodes; p=0.05), and nausea severity (0.91 versus 1.65 mean cm/day; p=0.01) over the 5-day period compared to patients wearing the inactive device. Vomiting was statistically significantly reduced during the delayed period (0.42 versus 1; p=0.032), whereas nausea was significantly reduced during the acute (0.71 versus 2.3; p=0.028) and delayed (1.8 versus 3.3; p=0.020) periods. FLIE scores did not differ between the two treatment groups (91 versus 80; p=0.088).Conclusions This study suggests that patients receiving moderately-high to highly emetogenic chemotherapy who experience nausea and vomiting despite scheduled antiemetics may benefit from the use of the Reliefband as an adjunct to antiemetics. Limitations of this study include differences in risk factors for emesis, chemotherapy, and antiemetic regimens. A larger, better, controlled randomized study is needed to better define optimal use of this device.Supported in part by Woodside Biomedical, Inc., Carlsbad, California USA.     

Ondansetron for acute gastroenteritis in children

QUESTION: In my pediatric practice I see many children with acute gastroenteritis. Their parents ask for antiemetic medications. Ondansetron has been well tolerated when used to control nausea and vomiting in patients receiving chemotherapy. Is there a role for it in managing acute gastroenteritis in children? ANSWER: Use of antiemetics is not indicated for treatment of acute gastroenteritis. Some evidence suggests ondansetron is clinically more effective and better tolerated and has a better side effect profile than other antiemetics, but does not suggest that it reduces hospital admission rates. Use of ondansetron, as with other antiemetics, continues to be at treating physicians' discretion, and potential adverse events should be considered before administration.     

Optimal selection of antiemetics in children receiving cancer chemotherapy

 Only a few studies have been carried out specifically on the prevention of nausea and vomiting in children receiving chemotherapy. In these patients older antiemetic drugs such as metoclopramide and phenothiazines had moderate efficacy and induced significant side effects, especially marked sedation and extrapyramidal reactions. In comparative trials the 5-HT₃ receptor antagonists have shown better efficacy and tolerability than chlorpromazine or metoclopramide combined with dexamethasone. The combination of a 5-HT₃ receptor antagonist plus dexamethasone is superior to a 5-HT₃ receptor antagonist alone and should be the standard antiemetic prophylaxis in all paediatric patients receiving highly or moderately emetogenic chemotherapy. The optimal dose and scheduling of these antiemetic drugs need to be studied, as well as the antiemetic efficacy, in the prevention of chemotherapy-induced delayed and anticipatory emesis in children.     

On the relationship between nausea and vomiting in patients undergoing chemotherapy

In comparative trials on antiemetic efficacy of different regimens, the positive correlation between the probabilities of vomiting and of nausea could hide some confounding effect. Our work seeks to detect such effects. The data from two large studies on prevention of cisplatin-induced emesis were re-analyzed using two multi-factorial logistic models. The first study compared ondansetron + dexamethasone (Ond + Dex) with metoclopramide + dexamethasone + diphenhydramine (Mtc + Dex + Dip), the second compared Mtc + Dex + Dip with Mtc + prednisolone. A group of 267 patients in the first study and 343 in the second, all evaluable for clinical efficacy, were followed for three subsequent cycles of chemotherapy. The antiemetic regimen administered and the complete protection from acute vomiting and nausea were recorded. In the first study (cycle 1), after adjustment for the presence/absence of vomiting, the two therapies were no longer found significantly different on complete protection from nausea: the greater efficacy of Ond + Dex in preventing nausea was due to a confounding effect. Instead, in the second study, the greater efficacy of Mtc + Dex + Dip in preventing both nausea and vomiting was confirmed. The results indicate that, when a correlation between two responses is detected, multifactorial analyses should be performed to identify the possible presence of some confounding effect. The proof that the presence/absence of vomiting is a confounding factor for the relationship between the different efficacy of the two antiemetic regimens for complete protection from nausea, highlighting the same efficacy of the two therapies in preventing nausea, supports the hypothesis of the existence of two kinds of nausea, one independent of vomiting, the other concomitant with it.     

Emesis induced by low or minimal emetic risk chemotherapy

For patients treated with low or minimally emetogenic chemotherapy there is little evidence from clinical trials supporting the choice of a given antiemetic therapy or of any treatment at all. The panel recognized the necessity of considering the introduction into clinical practice of new agents in these categories, particularly oral cytotoxic agents and targeted biological agents and also the possibility of over-treatment with antiemetics. There was consensus among panel members regarding the recommended treatment for patients receiving chemotherapy agents with low and minimal emetic risk. Patients without a history of nausea and vomiting for whom minimally emetic risk chemotherapy is prescribed should not routinely receive antiemetic prophylaxis. A single agent such as a low-dose corticosteroid is suggested for patients receiving agents of low emetic risk. If nausea and vomiting occurs during subsequent cycles of chemotherapy, prophylaxis with a single agent such as a substituted benzamide, a corticosteroid, or a phenothiazine should be administered. Only patients with persistent nausea and vomiting despite treatment with these recommended agents should receive a 5-HT3 receptor antagonist in the following cycles.