Antiemetics: Definition, Types, Side Effects and Treatments with Natural Antiemetics

They are those medications that are prescribed to help with nausea and vomiting that are side effects of other drugs.

This can include anesthesia drugs used during cancer surgery or chemotherapy .

Antiemetic medications are also used for nausea and vomiting caused by:

  • Cinetosis.
  • Morning sickness during pregnancy.
  • Severe cases of stomach flu ( gastroenteritis ).
  • Other infections

These medications work by interfering with the receptors for neurotransmitters involved in vomiting. Neurotransmitters are the cells that receive signals to send a nerve impulse.

The pathways that control these bodily reactions are complex. The type of antiemetic medicine used will depend on the cause.

Types of antiemetic drugs

Some antiemetic medications are taken by mouth. Others are available as an injection or as a patch placed on your body so that you do not have to swallow anything.

The type of antiemetic medicine you should take depends on what is causing your symptoms:

Antiemetics for motion sickness

These medications work by preventing your inner ear from fully detecting movement and include:

  • Dimenhidrinato (Dramamina, Gravol).
  • Meclizina (Dramamine Less Soñoliento, Bonine).

Antiemetics for stomach flu

The stomach flu, or gastroenteritis, is caused by a virus or bacteria. The over-the-counter medicine bismuth-subsalicylate (Pepto-Bismol) works by coating the lining of the stomach. You can also try OTC, glucose, fructose, or phosphoric acid (Emetrol).

Antiemetics for chemotherapy

Nausea and vomiting are a common part of chemotherapy treatment. Antiemetic drugs are used before and after chemotherapy to prevent symptoms.

Some prescription treatments include:

  • Serotonin 5-HT3 receptor antagonists : dolasetron (Anzemet), granisetron (Kytril, Sancuso), ondansetron (Zofran, Zuplenz), palonosetron (Aloxi).
  • Dopamine antagonists : prochlorperazine (Compazine), domperidone, olanzapine (Zyprexa).
  • NK1 receptor antagonists : aprepitant (Emend), rolapitant (Varubi).
  • Corticosteroids : dexamethasone.
  • Cannabinoides: cannabis (marihuana medicinal), dronabinol (Marinol).

Antiemetics for surgery

Postoperative nausea and vomiting (PONV) can be caused by anesthesia used during surgery. Prescription drugs used to treat PONV include:

  • 5-HT3 serotonin receptor antagonists : dolasetron, granisetron, ondansetron.
  • Dopamine antagonists : metoclopramide (Reglan), droperidol (inapsin), domperidone.
  • Corticosteroids : dexamethasone.

Antiemetics for morning sickness

Morning sickness is common during pregnancy. However, antiemetic drugs are generally not prescribed unless it is severe.

Hyperemesis gravidarum is a pregnancy complication that causes severe nausea and vomiting. If you have this condition, your doctor may prescribe:

  • Antihistamines : dimenhydrinate.
  • Vitamin B-6 (pyridoxine).
  • Dopamine antagonists : prochlorperazine, promethazine (Pentazine, Phenergan).
  • Metoclopramide (if other treatments don’t work).

Side effects

Side effects depend on the type of antiemetic medicine you take:

  • Bismuth subsalicylate : dark tongue, grayish stools.
  • Antihistamines : drowsiness, dry mouth.
  • Dopamine antagonists : dry mouth, fatigue, constipation, tinnitus, muscle spasms, restlessness.
  • Neurokinin receptor antagonists : decreased urination, dry mouth, heartburn.
  • Serotonin 5-HT3 receptor antagonists: constipation, dry mouth, fatigue.
  • Corticosteroids : indigestion, acne, increased appetite and thirst.
  • Cannabinoids : changes in perception, dizziness.

If you experience any of the following, see your doctor:

  • Worsening nausea or vomiting.
  • Severe constipation
  • Muscular weakness.
  • Seizures
  • Hearing loss.
  • Fast heartbeat
  • Severe drowsiness
  • Speak slowed down.
  • Psychological symptoms, such as hallucinations or confusion.

Treatments with natural antiemetics

The best known natural antiemetic is ginger (Zingiber officinale). Ginger contains 5-HT3 antagonists known as gingerols.

Clinical studies show that ginger can be effective in treating nausea and vomiting. Steep fresh ginger in hot water to make tea, or try candied ginger, gingerbread cookies, or ginger ale.

Peppermint essential oil aromatherapy can also be a safe and effective way to beat nausea and vomiting. Try rubbing a couple of drops on the back of your neck and taking a deep breath.

Cannabis has also been shown to be an effective antiemetic. It is now legally available in many states, but may be considered an illegal drug in others.

Safe antiemetic drugs for pregnancy

Medications for motion sickness such as meclizine and dimenhydrinate are safe for pregnant women.

Vitamin B-6 and dopamine antagonists have been found to be safe, but they are only used in severe cases of morning sickness.

Cannabis or marijuana are not safe to use during pregnancy. The drug is linked to lower birth weight and an increased risk of brain and behavior problems in children.

Pepto-Bismol is also not recommended.

Safe antiemetic drugs for children

It is always a good idea to consult a doctor before giving medication to children.

For motion sickness

Dimenhydrinate and diphenhydramine (Benadryl) can be used to treat nausea in children older than 2 years, but be sure to follow the dosing instructions.

For gastroenteritis

Recent studies have found that ondansetron can be safe and effective for children with a severe case of gastroenteritis.

Promethazine should not be used by infants or young children. Do not give bismuth subsalicylate to children 12 years of age or younger.

Remember:  there are many antiemetic medications to treat nausea and vomiting, but which medication you should try depends on what is causing your symptoms. Be sure to read labels carefully or follow your doctor’s instructions.

For mild cases of nausea or vomiting, try an herbal therapy such as ginger.