History of the drug 

Mechanism of action 

INDICATIONS 

1)Chemotherapy-Induced Nausea and Vomiting (CINV): Many chemotherapy drugs trigger nausea and vomiting. Antiemetics are a standard part of cancer treatment to improve patient comfort and adherence to therapy.

2)Postoperative Nausea and Vomiting (PONV): Anesthesia and surgery can cause nausea and vomiting after an operation. Antiemetics are often given preventatively or to treat PONV.

3)Motion Sickness: Antiemetics, particularly antihistamines and anticholinergics, are effective in preventing and treating motion sickness caused by travel.

4) Pregnancy-Related Nausea and Vomiting: "Morning sickness," or nausea and vomiting of pregnancy (NVP), can be treated with certain antiemetics that are considered safe during pregnancy.

5) Gastroenteritis: Viral or bacterial infections causing gastroenteritis can lead to nausea and vomiting. Antiemetics can provide symptomatic relief.

6) Migraines:  Nausea is a common symptom of migraines. Antiemetics can help alleviate this symptom and improve the absorption of oral migraine medications.

7) Vertigo and Inner Ear Disorders: Conditions affecting the inner ear can cause nausea and vomiting. Antiemetics can help manage these symptoms.

8) Radiation Therapy:  Similar to chemotherapy, radiation therapy can also induce nausea and vomiting.

Other Causes:  Antiemetics may be used for nausea and vomiting caused by medications, toxins, or other medical conditions.

Indication: Prevention of nausea and vomiting associated with chemotherapy, radiation therapy, and postoperative recovery , (They are  Selective 5-HT3 receptor antagonist)

Indications: Prevention and treatment of motion sickness-related nausea and vomiting (Note _Dopamine antagonist with prokinetic)

Indications: Treatment of nausea, vomiting and gastrointestinal motility disorders & Note: Dopamine D2 receptor antagonist with prokinetic property

*Serotonin antagonists: Headache, dizziness, constipation

*Antihistamines: Drowsiness

*Glucocorticoids: Insomnia, excitation, mood changes

*Anticholinergics: Dry mouth, vision changes, drowsiness

*NK-1 receptor antagonists: Headache, dizziness, possible severe allergic reactions (anaphylaxis)

*Dopamine antagonists: Dizziness, headache, movement disorders (dystonia, tardive dyskinesia)

*Cannabinoids: Vertigo, low blood pressure, dysphoria (unease or dissatisfaction)

Precautions and contraindications :

1. Pregnancy and Lactation:

Some antiemetics like ondansetron are used in pregnancy, especially for hyperemesis gravidarum, but caution is advised in the first trimester.

Metoclopramide may be used during pregnancy but should be limited in dose and duration.

2. Pediatrics and Geriatrics:

Promethazine is not recommended for children under 2 years due to the risk of respiratory depression.

Elderly patients are more prone to side effects like sedation, confusion, or dizziness.

3. Hepatic and Renal Impairment:

Dose adjustment or avoidance may be required for drugs like ondansetron and metoclopramide in liver or kidney dysfunction.

4. Cardiac Conditions:

Ondansetron can cause QT interval prolongation, increasing the risk of arrhythmias.

/Monitor patients with a history of cardiac arrhythmias or those on QT-prolonging medications.

5. Seizure Disorders:

Metoclopramide can lower the seizure threshold, so caution is required in epileptic patients.