Chemotherapy Induced Emesis – Mechanisms and Treatment: A Review

An update on palonosetron hydrochloride for the treatment of radio/chemotherapy-induced nausea and vomiting

INTRODUCTION

Nausea and vomiting are well recognized in different clinical situations, suggesting that no single mechanism is likely to be responsible for their production. Chemotherapy-induced nausea and vomiting (CINV) can have a negative impact on quality of life and this may lead to a refusal of curative therapy or to a decline in palliative benefits offered by cytotoxic treatment. Palonosetron is a new agent in the class of 5-HT3 receptor antagonists (5-HT3RAs), and differs from the other agents by its higher receptor-binding affinity and longer half-life. These pharmacological properties have resulted in improved antiemetic activity in clinical trials, particularly in the treatment of delayed CINV following moderate emetogenic chemotherapy (MEC).

AREA COVERED

A systematic review of the medical literature was completed to inform this update. MEDLINE, the Cochrane Collaboration Library and meeting materials from ASCO and MASCC were all searched.

EXPERT OPINION

Palonosetron was the only serotonin receptor antagonist approved for prevention of delayed CINV caused by MEC and its use was incorporated in guideline recommendations. To date, several treatment settings such as multiple day chemotherapy require further studies to improve emesis related to therapy.

Prevention of emesis by ICS 205-930 in children receiving cytotoxic chemotherapy

Nausea and vomiting are among the most frequent and severe acute side-effects of cytotoxic therapy and are not optimally controlled by conventional antiemetics. This situation warrants the evaluation of new classes of antiemetic agents such as the 5-HT3 receptor antagonists. 19 children with a median age of 9 years (range 2-16 years), treated with cytotoxic drug combinations that had previously caused nausea and vomiting refractory to conventional antiemetics, were given the selective 5-HT3 receptor antagonist ICS 205-930. The drug was given intravenously (i.v.) at 0.2 mg/kg (maximum 5 mg) during the chemotherapy infusion period and was continued orally for up to 5 days in chemotherapy courses containing cisplatin. The number of emetic episodes was recorded and the response was scored according to following scale: grade 1 = no nausea, no emetic episode; grade 2 = up to four episodes of vomiting and less than 5 h of nausea; grade 3 = five or more than five emetic episodes and/or nausea for at least 5 h. The 19 patients received a total of 169 various courses of chemotherapy combined with ICS 205-930. A score of 3 was observed during one course only, a score of 2 in 37 out of the 169 courses, including the four courses with cisplatin. The drug was very well tolerated. Side-effects possibly related to ICS 205-930 were mild to moderate headache in 4 patients during seven courses overall and obstipation in 3 patients during 11 courses. The results strongly suggest that ICS 205-930 is a highly effective and safe antiemetic agent in non-naive pediatric patients receiving non-cisplatin cytotoxic chemotherapy and who had failed conventional antiemetic treatment.

Comparison of the 5-hydroxytryptamine3 (serotonin) antagonist ondansetron (GR 38032F) with high-dose metoclopramide in the control of cisplatin-induced emesis

To compare ondansetron (GR 38032F), a 5-hydroxytryptamine3-receptor antagonist, with metoclopramide in the prophylaxis of acute cisplatin-induced emesis, we conducted a double-blind crossover study in 97 patients scheduled to receive cisplatin (80 to 100 mg per square meter of body-surface area) for treatment of cancer. None had received chemotherapy before this trial. Among the 76 patients who satisfactorily completed both parts of the study, complete or nearly complete control of emesis (i.e., no episodes of emesis occurred, or only one or two) was achieved in 57 of 76 treatments (75 percent) with ondansetron and in 32 of 76 treatments (42 percent) with metoclopramide (P less than 0.001). Ondansetron was also more effective in controlling acute nausea, as assessed with a visual-analogue scale (P = 0.019) or a graded scale (P = 0.024). There was a significant preference among patients for ondansetron (55 vs. 26 percent; P = 0.006). Dystonic reactions were observed during three treatments with metoclopramide; both agents were otherwise well tolerated. We conclude that ondansetron is more effective than metoclopramide in the control of cisplatin-induced nausea and vomiting, and that this suggests that serotonin is an important mediator of this side effect.

Inhibition of cisplatin-induced emesis in the pigeon by a non-psychotropic synthetic cannabinoid

The (+) enantiomer of the synthetic cannabinoid, 7-hydroxy-delta-6-tetrahydrocannabinol, dimethylheptyl homolog (HU-211), possesses significant antimetic efficacy in the pigeon. However, unlike all anti-emetic cannabinoids tested in the past, it is devoid of psychotropic (cannabimimetic) activity. The anti-emetic activity of HU-211 was determined in pigeons given 10 mg/kg i.v. cisplatin, a widely used antitumour agent, which is also a potent emetogenic agent at this dose. This activity was compared with that of delta-1-tetrahydrocannabinol (delta-1-THC). HU-211 pretreatment elicited a dose-related inhibition of cisplatin vomiting, with the optimal dose of HU-211 (2.5 mg/kg) inhibiting emesis by nearly 90%. Delta-1-THC in doses up to 5 mg/kg caused only an insignificant reduction in vomiting. The activity was increased in the presence of cupric chloride (0.8 mg/kg). The optimal dose of delta-1-THC (5.0 mg/kg) with CuCl2 very significantly diminished the total amount of vomitus expelled (up to 90%). However, it failed to inhibit emesis in 50% of all animals tested, did not significantly affect the time of onset of emesis and was highly psychotropic. The optimal dose of HU-211 (2.5 mg/kg) with CuCl2 inhibited emesis by 97%, significantly delayed the time on onset of emesis in the very few animals that did vomit and was completely non-psychotropic. The curve for the antiemetic effect of HU-211 was U-shaped over a narrow dose range. The present report demonstrates that complete separation of psychotropic and antiemetic activities is possible in the cannabinoid series.