Nausea/vomiting antiemetic regimens

There is little evidence supporting the use of 5HT3-receptor antagonists beyond the first 24 hours, and corticosteroids appear to be the most effective component of antiemetic regimens used to prevent delayed nausea and vomiting (American Society of Clinical Oncology et ah, 2006). 

D. Use of antiemetic regimen including dexametha-sone for delayed nausea and vomiting... 

The efficacy of any of the regimens for EC declines if they begin more than 72 hours after intercourse. Treatment is totally ineffective by 7 days, when implantation usually occurs. Patients may experience nausea, vomiting, and breast tenderness with this regimen. Although some clinicians prescribe antiemetics prophylactically, others recommend simply repeating the dose if the patient vomits within an hour of taking the pills. 

When used for the treatment of chemotherapy-induced nausea and vomiting, aprepitant is given over 3 days as part of a combination antiemetic regimen that also includes a 5HT antagonist as well as a corticosteroid. The recommended dose is 125 mg orally 1 hour before chemotherapy on day 1 and 80 mg orally each morning on days 2 and 3. 

Nausea and vomiting that occur within 24 hours of chemotherapy administration is defined as acute, whereas when it starts more than 24 hours after chemotherapy administration, it is defined as delayed. The emetogenic potential of the chemotherapeutic agent or regimen (see Table 27-2) is the primary factor to consider when selecting an antiemetic for prophylaxis of CINV. 

If chemotherapy-associated nausea and vomiting are not well controlled, some patients develop nausea and vomiting in anticipation of their next chemotherapy treatment. This conditioned response, once it occurs, is often difficult to treat. Adequate early antiemetic treatment, particularly with regimens that include a benzodiazepine, may prevent this reaction. 

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