- Start with an optimal antiemetic regimen starting with the first cycle of chemotherapy in order to counteract the amplification of the nausea that often occurs with a new treatment.
- Start the oral antiemetic regimen 1-2 hours before chemotherapy and approx. 15-30 minutes before an intravenous injection.
- If the patient is already nauseous, the medication should be administered parenterally or rectally.
Mildly emetic chemotherapy
- Metoclopramide 10 mg is given intravenously before treatment with cytostatic agents.
- Metoclopramide 10 mg is given orally uptil 3 times.
Moderately emetic chemotherapy
Ondansetron 8 mg orally 2 x daily. In the event of nausea before treatment, give ondansetron intravenously. If this has little effect, try ondansetron 8 mg x 3 or change to a 5HT3-antagonist, for example, tropisetron 5 mg orally/intravenously or palonosetron 250 µg intravenously.
Highly emetic chemotherapy, or if other treatment does not help
For highly emetic chemotherapy drugs, or if other treatment is not adequate, a 5HT3-antagonist can be given orally or intravenously. It should be combined with dexamethasone 8-16 mg intravenously ½-1 hour before treatment, and further, 8 mg x 2 intravenously or orally on the first day.
In addition, dopamine antagonists may be given, for example, metoclopramide 10 mg x 3.
In some cases, traditional nausea treatment is not sufficient. In this case, the patient can be treated with aprepitant. Aprepitant is used for highly emetic regimens and for patients where the usual antiemetic treatment has failed during moderate emetogenic treatment. Aprepitant is given orally 1 hour before chemotherapy and is combined with dexamethasone and 5HT3-antagonists: 125 mg capsules orally on day 1, then 80 mg orally on days 2-5, depending on the duration of the treatment. Aprepitant can enhance the effect of taxane and etoposide, as well as vinorelbine, and can reduce the effect of warfarin.
The regimen is repeated daily if highly emetic treatment is given over a number of days.
Aprepitant in combination with dexamethasone and 5HT3-antagonists is preferable if there is a high risk of delayed nausea and vomiting. This is offered especially to patients who have previously experienced delayed nausea.
In the event of conditional nausea, diazepam or other tranquilizers may be considered. Diversion or desensitization can be tried in more serious cases.