What are intravenous (IV) nausea medications that do not lower the seizure threshold?

From the Guidelines

Intravenous (IV) nausea medications that do not lower the seizure threshold include ondansetron, granisetron, palonosetron, and dexamethasone. These medications are considered safe for patients with seizure disorders or those at risk for seizures 1. Ondansetron is typically administered at 4-8 mg IV every 8-12 hours, granisetron at 1 mg IV daily, palonosetron at 0.25 mg IV as a single dose, and dexamethasone at 4-10 mg IV.

Key Points to Consider

• 5-HT3 receptor antagonists (ondansetron, granisetron, palonosetron) and corticosteroids (dexamethasone) are effective in controlling nausea and vomiting without affecting neuronal excitability that could trigger seizures 1.
• Other antiemetics like metoclopramide, prochlorperazine, and promethazine should be avoided in seizure-prone patients as they can lower the seizure threshold.
• Palonosetron has been shown to be superior to other 5-HT3 antagonists in preventing delayed emesis 1.
• The safety and side-effect profiles of palonosetron were indistinguishable from the control 5-HT3 antagonists (ondansetron and dolasetron) according to data submitted to the FDA 1.

Administration and Monitoring

• When administering these medications, it's essential to monitor for potential side effects such as headache, constipation, or QT interval prolongation (particularly with ondansetron) 1.
• The medications work by blocking serotonin receptors in the chemoreceptor trigger zone and gastrointestinal tract (5-HT3 antagonists) or by reducing inflammation and inhibiting prostaglandin production (dexamethasone), effectively controlling nausea and vomiting without affecting neuronal excitability that could trigger seizures.

From the FDA Drug Label

In healthy volunteers (N=64), dolasetron mesylate in single intravenous doses up to 5 mg/kg produced no effect on pupil size or meaningful changes in EEG tracings. Results from neuropsychiatric tests revealed that dolasetron mesylate did not alter mood or concentration.

IV Nausea Medications that Do Not Lower Seizure Threshold:

• Dolasetron (IV) does not lower the seizure threshold, as it did not produce meaningful changes in EEG tracings in healthy volunteers 2.

From the Research

IV Nausea Medications

• Ondansetron is an IV nausea medication that has been studied for its effectiveness in managing nausea and vomiting associated with various conditions, including acetaminophen poisoning 3.
• However, there have been reports of ondansetron-induced seizures, dystonia, and hypoglycemia in some patients 4, 5, which raises concerns about its safety in certain populations.
• Despite these concerns, ondansetron has been shown to be effective in controlling nausea and vomiting in patients with neurosurgical trauma without lowering the seizure threshold 6.
• Another option is granisetron, a selective serotonin3 (5-hydroxytryptamine3, 5-HT3) receptor antagonist that has significant antiemetic activity against chemotherapy-induced nausea and vomiting 7.
• Granisetron has been shown to be well tolerated and effective in controlling acute nausea and vomiting, with a simpler dosage regimen than traditional antiemetic regimens 7.

Key Considerations

• The choice of IV nausea medication should be based on the individual patient's needs and medical history.
• Ondansetron and granisetron are both effective options, but their safety profiles and potential side effects should be carefully considered 3, 4, 5, 6, 7.
• Further research is needed to fully understand the risks and benefits of these medications in different patient populations.