title: Anti-emetic drugs in oncology: pharmacology and individualization by pharmacogenetics.
abstract: OBJECTIVE
  Nausea and vomiting are the most distressful side effects of cytotoxic drugs in cancer patients. Antiemetics are commonly used to reduce these side effects. However, the current antiemetic efficacy is about 70-80% in patients treated with highly-emetogenic cytotoxic drugs. One of the potential factors explaining this suboptimal response is variability in genes encoding enzymes and proteins which play a role in metabolism, transport and receptors related to antiemetic drugs. Aim of this review was to describe the pharmacology and pharmacogenetic concepts of of antiemetics in oncology.
  
  
  METHODS
  Pharmacogenetic and pharmacology studies of antiemetics in oncology published between January 1997 and February 2010 were searched in PubMed. Furthermore, related textbooks were also used for exploring the pharmacology of antiemetic drugs. The antiemetic drugs which were searched were the 5-hydroxytryptamine 3 receptor antagonists (5-HT3RAs), dopamine antagonists, corticosteroids, benzodiazepines, cannabinoids, antihistamines and neurokinin-1 antagonists.
  
  
  RESULTS
  The 5-HT3RAs are widely used in highly emetogenic chemotherapy in combination with dexamethasone and a neurokinin-1 antagonist, especially in acute phase. However, the dopamine antagonists and benzodiazepines were found more appropriate for use in breakthrough and anticipatory symptoms or in preventing the delayed phase of chemotherapy induced nausea and vomiting. The use of cannabinoids and antihistamines need further investigation. Only six articles on pharmacogenetics of the 5-HT3RAs in highly emetogenic chemotherapy are published. Specifically, these studies investigated the association of the efficacy of 5-HT3RAs and variants in the multi drug resistance 1 (MDR1) gene, 5-HT3A,B and C receptor genes and CYP2D6 gene. The pharmacogenetic studies of the other antiemetics were not found in this review.
  
  
  CONCLUSIONS
  It is concluded that pharmacogenetic studies with antiemetics are sparse. It is too early to implement results of pharmacogenetic association studies of antiemetic drugs in clinical practice: confirmation of early findings is required.
authors.affiliation: Department of Pharmacy, Ahmad Dahlan University, Yogyakarta, Indonesia.
authors.forename: D A
authors.initials: DA
authors.lastname: Perwitasari
authors.forename: Hans
authors.initials: H
authors.lastname: Gelderblom
authors.forename: Jarir
authors.initials: J
authors.lastname: Atthobari
authors.forename: Mustofa
authors.initials: M
authors.lastname: Mustofa
authors.forename: Iwan
authors.initials: I
authors.lastname: Dwiprahasto
authors.forename: Johan W R
authors.initials: JW
authors.lastname: Nortier
authors.forename: Henk-Jan
authors.initials: HJ
authors.lastname: Guchelaar
mesh_terms: D000932:Antiemetics / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D006801:Humans; D009325:Nausea / Q000139:chemically induced / Q000188:drug therapy* / Q000235:genetics / Q000517:prevention & control; D010597:Pharmacogenetics; D012307:Risk Factors; D017211:Treatment Failure; D016896:Treatment Outcome; D014839:Vomiting / Q000139:chemically induced / Q000188:drug therapy* / Q000235:genetics / Q000517:prevention & control
chemical_list: D000932:Antiemetics; D000970:Antineoplastic Agents