Medication to counteract nausea and vomiting is the 4th part of our review of Chemotherapy in Ireland
Posted by Eamonn Brady on
Chemotherapy Part 4
Medication prescribed to counteract nausea and vomiting from chemotherapy
5-HT3 receptor antagonists
The first group of anti-emetic drugs used to counteract CINV are 5-HT3 receptor antagonists. These drugs work by blocking serotonin, a neurotransmitter in the gut that can cause nausea and vomiting. The most used 5-HT3 receptor antagonists in Ireland are ondansetron, granisetron, and palonosetron. Ondansetron is available as tablets, oral solution, and injection, while granisetron and palonosetron are available as tablets and injection. Palonosetron is the most recently developed drug in this group, and it has a longer half-life compared to the other drugs, meaning it lasts longer in the body and can be effective in preventing delayed CINV. These drugs are most effective when given at least 30 minutes before chemotherapy.
Corticosteroids
Another group of anti-emetic drugs used to counteract CINV are the corticosteroids, such as dexamethasone. Corticosteroids are believed to block the production of prostaglandins, which can trigger nausea and vomiting. Dexamethasone is available as tablets and injection. The oral format is mainly used in cancer care. It is often used in combination with 5-HT3 receptor antagonists, as it can improve the effectiveness of these drugs. Dexamethasone can be given before or after chemotherapy.
NK1 receptor antagonists
A third group of anti-emetic drugs used to counteract CINV are the NK1 receptor antagonists, such as aprepitant and fosaprepitant. These drugs work by blocking substance P, a neuropeptide that can trigger nausea and vomiting. Aprepitant is available as capsules and injection, while fosaprepitant is available as injection only. These drugs are most effective when given at least one hour before chemotherapy.
Other anti-emetics
Other anti-emetics used in Ireland to counteract CINV include metoclopramide, which is a dopamine receptor antagonist, and cannabinoids such as dronabinol and nabilone. Metoclopramide is available as tablets and injection. It is often used as a second-line drug when other anti-emetic drugs have failed. Cannabinoids are only used if other anti-emetic drugs are not effective, as they can cause central nervous system side effects.
National Cancer Control Programme (NCCP) guidelines in Ireland recommend 5-HT3 receptor antagonists and dexamethasone for highly and moderately emetogenic chemotherapy, and the addition of aprepitant for highly emetogenic chemotherapy. For chemotherapy that causes less nausea nad vomiting, the guidelines recommend metoclopramide or 5-HT3 receptor antagonists as first-line therapy, and cannabinoids as second-line therapy.
Non-pharmacological techniques that may help reduce CINV include acupuncture, acupressure, and relaxation techniques.
To be continued… next week I discuss side effects of anti-sickness drugs used during chemotherapy.
For comprehensive and free health advice and information call in to Whelehans Pharmacies, log on to www.whelehans.ie or dial 04493 34591 (Pearse St) or 04493 10266 (Clonmore).