Serotonin and Anticancer Drug-induced Emesis

[Consideration of the Characteristics of Oral Iron Preparations from the Viewpoint of the Mechanism of Nausea and Vomiting]

The nausea and vomiting that occur as a result of oral iron administration for the treatment of iron-deficiency anemia (IDA) can cause significant physical and emotional stress in patients. Because iron is absorbed from the intestine as ferrous iron, the most widely used treatment for IDA is oral ferrous agents. However, ferrous forms are more toxic than ferric forms because ferrous forms readily generate free radicals. A randomized, double-blind, active-controlled, multicenter non-inferiority study conducted in Japan showed that ferric citrate hydrate (FC) was just as effective as sodium ferrous citrate (SF) in the treatment of IDA, with a lower incidence of adverse reactions such as nausea and vomiting compared with SF. Animal studies have shown that chemotherapy-induced nausea and vomiting (CINV) involves the release of 5-hydroxytryptamine from enterochromaffin cells by free radicals, and that some chemotherapeutic agents cause hyperplasia of these cells. Enterochromaffin cells also contain substance P, which is known to be also closely related to CINV. We found that administration of SF to rats causes hyperplasia of enterochromaffin cells in the small intestine, whereas FC has no effect on enterochromaffin cells. Oral iron agents may induce nausea and vomiting via the effect of ferrous iron on reactive oxygen species production in the intestine and subsequent enterochromaffin cell hyperplasia. Further research to elucidate the detailed mechanism of enterochromaffin cell hyperplasia induced by ferrous iron preparations is needed to develop a treatment for iron deficiency anemia that causes less gastrointestinal damage.

Genotype frequencies for polymorphisms related to chemotherapy-induced nausea and vomiting in a Japanese population

Background

Genotype frequencies for chemotherapy-induced nausea and vomiting (CINV)-related polymorphisms have not yet been reported for Japanese subjects.

Methods

We analyzed 10 genotype frequencies for following polymorphisms associated with the development of CINV: serotonin 5-HT₃ receptors (HTR3); neurokinin-1 receptors (Tachykinin-1 receptors, TACR1); dopamine D₂ receptors (DRD2); and catechol-O-methyltransferase (COMT).

Results

All polymorphisms were successfully genotyped in 200 Japanese subjects and were in Hardy-Weinberg equilibrium. Almost all genotype frequencies were similar to those in the HapMap database or in the previous reports, while frequencies for the Y192H polymorphism in TACR1 were different in Japanese subjects from those in a previous report.

Conclusions

The present study revealed genotype frequencies for polymorphisms, which were related to the appearance of CINV in Japanese subjects. Individual therapy based on genotype variations for each race is needed to allow cancer patients to undergo chemotherapy more safely and to understand etiology of CINV.

Antiemetic placebo: Reduce adverse drug interactions between chemotherapeutic agents and antiemetic drugs in cancer patients

Cancer patients receiving chemotherapy often require a wide range of drugs to manage symptoms of their cancer. The adverse drug interactions are common in the field of medical oncology. Chemotherapy-induced nausea and vomiting (CINV) continues to have a considerable effect on the physical and psychological well-being of patients with cancer, despite significant advances in antiemetic drugs since the 1990s. Fortunately, evidence-based interventions suggested that to a certain extent antiemetic effects can be achieved by use of placebo appropriately. Placebo effect can be reinforced by conferring much meaning. Thus physician can replace antiemetic drugs with reinforced meaningful antiemetic placebo to get better prevention and treatment efficacy for CINV while reduce the unnecessary adverse drug interactions induced by antiemetic drugs and chemotherapeutic agents.

Antiemetic activity of corticosteroids in patients receiving cancer chemotherapy: dosing, efficacy, and tolerability analysis

BACKGROUND

Chemotherapy and radiotherapy remain the standards of treatment for many patients with cancer, but these modalities are often limited by distressing side-effects, most notably chemotherapy-induced nausea and vomiting (CINV).

METHODS

This paper considers the role of corticosteroids in CINV prophylaxis. Clinical trial results and treatment guidelines indicate that even with the emergence of new serotonin and neurokinin receptor antagonists, corticosteroids continue to play an important role in antiemesis for oncology patients. Numerous clinical trial results have demonstrated that both dexamethasone and methylprednisolone are effective as monotherapy and in combination with older and more recently developed antiemetic agents in patients receiving a wide range of chemotherapeutic regimens used for treatment of different cancers.

CONCLUSIONS

With the increasing number of antineoplastic regimens and factors specific to individual patients, it is important to frequently review antiemetic treatment options and continually monitor therapeutic progress to establish the optimal therapy for each patient.