- Nausea has been reported to occur in approximately 25 percent of patients
- prophylactic measures generally are not required at the initiation of therapy.
- Mechanisms for nausea may include direct stimulation of the chemoreceptor trigger zone (CTZ), reduced gastrointestinal motility, or enhanced vestibular sensitivity
- Nausea that results from opioids usually is transient; however, treat if substantial nausea and vomiting develop
What are management approaches?
- Schedule anti‐emetics. Start with a low‐cost drug such as a dopamine receptor antagonist (e.g., prochlorperazine); use 5HT3 antagonists for more refractory cases. Antihistamines or scopolamine may be helpful for patients who note increased nausea from motion.
- Adjust the opioid dose. If good pain relief is achieved but associated with nausea, it may be possible to lower the dose, still retain good analgesia, but eliminate the nausea. Most patients develop rapid tolerance to the emetic effects, so that within 3‐7 days, at a constant opioid dose, the emetic effect will abate.
- Switch to a different opioid. Since all mu agonist opioids cause nausea, there is little rationale for changing drugs; however, patients may be more sensitive to one opioid compared to another, thus a change is warranted when the above options are not effective
Additional Medical Information:
- based on MOH Blue Book, Granisetron is indicated for prevention and treatment of nausea and vomiting associated with radiotherapy and chemotherapy. thus if it is an UNLABELLED use for this indication in Malaysia
- Corticosteroids have an unclear mechanism of action for treating nausea caused by opioids. Jitteriness, confusion, and increased appetite are adverse effects that need to be considered before starting corticosteroids
- some references do suggest metoclopramide dose of 10-20mg oral or IV every 3-4h
- Opioid Induced Nausea. http://prc.coh.org/pdf/Nausea-FF%203-10.pdf
- Managemnet of Common Opioid Induced Adverse Effect (2006)
- www.drugs.com
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