Antinausea

Antinausea, or antiemesis, refers to interventions that prevent or relieve nausea and vomiting. It includes pharmacologic antiemetics and nonpharmacologic strategies used in clinical care, travel, and pregnancy. Most agents work by blocking signals to the vomiting center in the brain or by influencing gastrointestinal motility.

Common drug classes and examples:

- 5-HT3 receptor antagonists (ondansetron, granisetron) are widely used for chemotherapy- and surgery-related nausea.

- Dopamine antagonists (metoclopramide, prochlorperazine) have antiemetic and prokinetic effects but can cause movement-related side effects.

- Neurokinin-1 (NK1) antagonists (aprepitant, fosaprepitant) are often used in combination for chemotherapy-induced nausea.

- Antihistamines (dimenhydrinate, meclizine) and anticholinergics (scopolamine) are common for motion sickness and vertigo.

- Corticosteroids (dexamethasone) are frequently used as adjuncts in chemotherapy regimens.

Nonpharmacologic approaches include adequate hydration, small frequent meals, ginger, acupressure or acupuncture, and avoiding provoking stimuli. In pregnancy, options such as certain vitamin B6 preparations and other approved measures are used under medical guidance.

Safety and considerations:

Adverse effects vary by agent and may include drowsiness, dry mouth, constipation, extrapyramidal symptoms, or QT prolongation. Drug interactions and patient-specific factors (cardiovascular disease, pregnancy, age) influence choice and dosing. Antinausea medications are commonly employed in perioperative care to prevent PONV, in oncology for CINV, in obstetrics for pregnancy-related nausea, and in travel medicine for motion sickness. The efficacy of a given agent depends on the underlying cause and individual response.