Dexamethasone antiemetic effects

The antiemetic effect of combined intravenous ondansetron 8 mg, oral dexamethasone 20 mg, and oral lorazepam 0.5 mg was significantly better than that of intravenous metoclopramide 10 mg, dexamethasone 20 mg, and oral lorazepam 0.5 mg in 30 patients receiving chemotherapy for ovarian cancer in a randomized trial (23). All the antiemetics were given 30 minutes before and 6 hours after chemotherapy. Significantly more patients given metoclopramide (40% versus 13%) complained of adverse effects. The most frequent adverse effects with both regimens were sedation and headache. 

Corticosteroids are widely used throughout medical practice. In cancer therapy, prednisone and dexamethasone are the most frequently used. They have a lytic effect on lymphoma and myeloma cells, reduce the edema associated with brain metastases, reduce immunological and allergic reactions and exert an antiemetic effect alone and with 5-HT3 blockers. The many side effects of corticosteroids are often the consequence of the desired effect on the disease process being treated also impacting the normal tissues adversely. These toxicities are well known as they are seen throughout clinical medicine. 

The optimal dose for glucocorticoid analgesic effect is not established, as controlled dose-finding studies have not been performed. For the antiemetic effect, a dexamethasone dose of 3-4 mg seems to be optimal, whereas for analgesia 8-16 mg seems to be necessary in adults. 

Combinations of antiemetics may be the most effective method of preventing PONV for high-risk patients.7,42 Droperidol plus a 5-HT3 antagonist or dexamethasone plus a 5-HT3 antagonist are effective combinations.43,44 Three-drug combinations such as dexamethasone, droperidol, and a 5-HT3 antagonist have not been formally studied but may be a reasonable approach.42... 

Chlorpromazine, prochlorperazine, promethazine, methylprednisolone, lorazepam, metoclopramide, dexamethasone, or dronabinol may be used for adult patients. Around the clock dosing should be considered. The choice of specific agent should based on patient specific factors, including potential for adverse drug reactions, and cost. SSRIs are effective for breakthrough nausea and vomiting but they are not superior to the less expensive antiemetics above. 

Aprepitant (Emend) [Centrally Acting Antiemetic] Uses Pre-vents N/V assoc w/ emetogenic CA chemo (eg, cisplatin) (use in combo w/ other antiemetics) Action Substance P/neurokinin l(NKi) receptor antagonist Dose 125 mg PO day 1, 1 h before chemo, then 80 mg PO qAM days 2 3 Caution [B, /-] Contra Use w/ pimozide, Disp Caps SE Fatigue, asthenia, hiccups Interactions T Effects W/ clarithromycin, diltiazem, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, troleandomycin T effects OF alprazolam, astem-izole, cisapride, dexamethasone, methylprednisolone, midazolam, pimozide, terfe-nadine, triazolam, chemo agents, eg, docetaxel, etoposide, ifosfamide, imatinib, irinotecan, paclitaxel, vinblastine, vincristine, vinorelbine i effects W/ paroxetine,... 

Corticosteroids (dexamethasone, methylprednisolone) have antiemetic properties, but the basis for these effects is unknown. These agents are commonly used in combination with other agents in the... 

Corticosteroids Dexamethasone and methylprednisolone used alone are effective against mildly to moderately emetogenic chemotherapy. Their antiemetic mechanism is not known, but may involve blockade of prostaglandins. These drugs can cause insomnia and hyperglycemia in patients with diabetes mellitus. 

In another open trial the combination of intravenous granisetron (1 mg) plus dexamethasone (10 mg) was effective and well tolerated for antiemetic control in 100 bone-marrow transplant patients receiving highly emeto-genic chemotherapy with or without irradiation (9). Adverse effects were mild headache, diarrhea, and constipation were the most frequent. 

Dexamethasone is an effective prophylactic agent when administered either alone or in combination with other antiemetic drugs before the induction of anesthesia." Droperidol has been one of the most effective agents for PONV prophylaxis. At a dose of 1.25 mg IV, it was more effective and much less costly than combination therapy with ondansetron 4 mg TV and droperidol 0.625 mg TV." As discussed earlier, the recent FDA black box warning has effectively removed droperidol from clinical use. As a result of conflicting data. 

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