What are antiemetics (anti-emetic medications)?

From the Guidelines

Antiemetics are medications used to prevent or treat nausea and vomiting, and the choice of antiemetic depends on the cause and severity of the nausea, with options including 5-HT3 antagonists, corticosteroids, and NK1 receptor antagonists.

Types of Antiemetics

• 5-HT3 antagonists, such as ondansetron and palonosetron, are effective for preventing acute and delayed nausea and vomiting, especially in patients receiving chemotherapy 1
• Corticosteroids, such as dexamethasone, can enhance the effectiveness of other antiemetics and are often used in combination with 5-HT3 antagonists 1
• NK1 receptor antagonists, such as aprepitant, are particularly effective for preventing chemotherapy-induced nausea and vomiting 1

Recommendations for Use

• For mild nausea, ondansetron 4-8mg orally every 8 hours is often the first-line choice due to its efficacy and minimal side effects
• For more severe cases, a combination approach may be needed, such as adding promethazine 12.5-25mg orally or IV every 6 hours, or metoclopramide 10mg orally or IV every 6 hours
• For chemotherapy-induced nausea, aprepitant (125mg on day 1, then 80mg on days 2-3) is particularly effective, and palonosetron is preferred over other 5-HT3 antagonists for high emetic risk chemotherapy 1

Important Considerations

• The cause of nausea should be considered when selecting an antiemetic, as different causes respond better to specific medications
• Side effects vary but can include drowsiness, dry mouth, constipation, and rarely, extrapyramidal symptoms with metoclopramide
• The emetogenic potential of oral therapeutic agents should be considered, and antiemetic prophylaxis is recommended for certain oral agents, such as altretamine and busulfan 1

From the FDA Drug Label

Aprepitant capsules, in combination with other antiemetic agents, are indicated in patients 12 years of age and older for the prevention of: • acute and delayed nausea and vomiting associated with initial and repeat courses of highly emetogenic cancer chemotherapy (HEC) including high-dose cisplatin • nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy (MEC).

Antiemetics are medications used to prevent or treat nausea and vomiting. In the context of the provided drug labels, antiemetic agents refer to medications like aprepitant, which are used in combination with other agents to prevent nausea and vomiting associated with chemotherapy or postoperative nausea and vomiting.

• Key points about antiemetics include:
  • Used to prevent or treat nausea and vomiting
  • Can be used in combination with other medications
  • Aprepitant is an example of an antiemetic agent 2, 2, 2

From the Research

Definition and Purpose of Antiemetics

• Antiemetics, also known as anti-emetic medications, are drugs used to prevent or treat nausea and vomiting [ 3 , 4 ].
• These medications are often used to manage chemotherapy-induced nausea and vomiting (CINV) and postoperative nausea and vomiting (PONV) [ 3 , 4 ].

Types of Antiemetics

• 5-hydroxytryptamine3 (5-HT3) receptor antagonists, such as granisetron, dolasetron, ondansetron, palonosetron, and tropisetron, are a class of antiemetics that work by blocking the action of serotonin at 5-HT3 receptors [ 3 , 4 , 5 ].
• Substance P/neurokinin1 receptor antagonists are another class of antiemetics that have been developed to manage CINV and PONV [ 3 ].

Mechanism of Action and Efficacy

• Antiemetics work by blocking the signals to the brain that trigger nausea and vomiting [ 4 , 6 ].
• Studies have shown that antiemetics, such as ondansetron, are effective in preventing and treating CINV and PONV [ 4 , 6 , 7 ].

Side Effects and Safety

• Antiemetics can cause side effects, such as headache, constipation, and abdominal pain [ 4 , 5 , 6 ].
• The safety profile of antiemetics can vary depending on the specific medication and patient population [ 5 ].