Should we know exactly about antiemetic drugs?

You probably feel nauseous and vomit sometimes, right? It's really uncomfortable. So today we're going to talk about a type of medicine that can help control and stop these things like nausea and vomiting. These are what we call antiemetic drugs . Let's see what these are, how they work, and when they're used.

What are these antiemetic drugs?

Simply put, ``Antiemetic drugs`` are drugs that are given to prevent nausea and vomiting, or to treat it if it occurs. ``Anti-`` means ``against.'' The word ``-emetic`` comes from the word ``emesis``. In medicine, the word ``(emesis)`` is also used for vomiting. So, these are drugs that are given to prevent vomiting.

There are several types of ``Antiemetic`` medications, which are different ``drug classes``. Some of them you can get from the pharmacy without a prescription (called ``Over-the-counter`` or ``OTC`` medications). But some of them can only be taken with a prescription from a doctor (`` prescription`` medicines). Since there are many causes of nausea and vomiting, there are specific ``Antiemetic`` medications that are suitable for each cause.

When do I need anti-vomiting medicine?

Now you're probably thinking, 'So when would I need a medicine like this?'

Vomiting is actually sometimes a protective reaction of our body. Think about it, if you eat spoiled food, or if you have a stomach ache (stomach flu), it's better to vomit and get rid of the poison from your body.

However, if vomiting is severe or occurs frequently, it can lead to serious health problems. For example:

• Bone fractures can even occur, especially in the elderly.
• Dehydration is the loss of water from the body.
• Esophageal rupture, also known as Boerhaave's syndrome.
• Loss of appetite .
• Nutritional deficiencies (`Malnutrition`).
• Mental changes.
• Tooth enamel wears away.
• Surgical wounds can reopen (`Reopening of surgical wounds`).

Because of things like this, doctors sometimes prescribe this ``Antiemetic`` medication to prevent vomiting or to stop vomiting that has already started.

Help for persistent nausea and vomiting

If you have severe or prolonged nausea and vomiting, your doctor may prescribe an ``Antiemetic'' medication. Let's look at some examples.

• Radiation- and chemotherapy-induced nausea and vomiting (CINV): Nausea and/or vomiting are common side effects of chemotherapy. Radiation therapy to the brain, gastrointestinal tract, or liver can also cause these side effects. For this reason, doctors recommend that you take an antiemetic while you are undergoing chemotherapy or radiation therapy. This is because excessive nausea and vomiting can be very dangerous for someone with cancer.
• Nausea and vomiting during pregnancy (also known as `morning sickness`): Some doctors recommend over-the-counter `antiemetics` for this. Similarly, for `hyperemesis gravidarum`, doctors recommend either over-the-counter or prescription `antiemetics`.

The most important thing is to talk to your doctor about when and how to use these `(Antiemetic)` medications. Sometimes, especially in situations like `(CINV)`, you may need to use more than one `(Antiemetic)`. If you have nausea and vomiting during pregnancy , you should definitely talk to a doctor before taking any medicine from the pharmacy.

A remedy for sudden nausea and vomiting

Sometimes, when nausea and vomiting are almost certain to occur, doctors prescribe this ``Antiemetic`` medication to prevent it. Think about it this way.

Many medications, such as anesthetics (used in anesthesia) and opioids , can cause nausea and vomiting as a side effect. Doctors use these medications for things like surgeries. So, to prevent nausea and vomiting after surgery (postoperative nausea and vomiting - PONV), they will give you an antiemetic.

Vertigo and motion sickness can also cause nausea and vomiting. If you are going to be in a situation where you are likely to experience these symptoms (for example, on a long journey, such as on a bus or ship), your doctor may recommend that you take an antiemetic.

Apart from this, there may be other situations where a doctor may prescribe you an ``Antiemetic''.

What medications are there to stop vomiting?

Now let's see what types of antiemetic drugs are available. There are mainly seven categories of ``Antiemetic'' drugs. There are several types of drugs in each category.

1. Serotonin antagonists

These are a very commonly used type of ``Antiemetic`` that is specifically given to treat nausea and vomiting. Examples of these are:

• `Granisetron (Kytril®)`
• `Ondansetron (Zofran®)`
• `Palonosetron (Aloxi®)`

This medication is approved by the US Food and Drug Administration ( FDA ) to prevent the following:

• `CINV` (cancer treatment-induced nausea and vomiting) and nausea and vomiting caused by radiation therapy.
• `PONV` (that means post-operative nausea and vomiting).

However, sometimes doctors prescribe these medications for other conditions. This is called `off-label` use, meaning they are used for purposes other than those approved by the FDA.

2. Antihistamines

Antihistamines, especially those that block the histamine 1 (H1) receptor, are primarily used by doctors to control symptoms related to allergies. However, some of these are FDA-approved to prevent and treat nausea and vomiting caused by motion sickness and vertigo. Sometimes, doctors may prescribe them off-label if other antiemetics for nausea and vomiting during pregnancy have not worked. Here are some types of antihistamines for vomiting:

• `Dimenhydrinate` chewable tablets (`Dramamine®`)
• Diphenhydramine capsules or tablets (Benadryl®)
• Vitamin B6 with `Doxylamine succinate` – This is the first-line treatment for nausea and vomiting during pregnancy.
• `Meclizine (Antivert®, Bonine®, Dramamine-N®)`
• `Promethazine (Phenergan®)`

Medications such as diphenhydramine and dimenhydrinate can also help prevent PONV (post-operative nausea and vomiting), but they are not usually the first-line medications for it.

3. Glucocorticoids

Glucocorticoids (or Corticosteroids) are a class of drugs that doctors use primarily for their anti-allergic and anti-inflammatory properties. However, some Glucocorticoids also act as antiemetics.

Dexamethasone (Baycadron Elixer®, Decadron®, Zema-Pak®, and other brands) is the main glucocorticoid used by doctors to prevent CINV (cancer treatment-induced nausea) and PONV (post-operative nausea).

Doctors sometimes give a `(Glucocorticoid)` along with other `(Antiemetic)` types to prevent nausea and vomiting. But unlike some other `(Antiemetic)`, `(Glucocorticoids)` cannot cure nausea and vomiting once it has started. That is, they are only given to prevent it.

4. Anticholinergics

Anticholinergics (also known as antimuscarinics) are a type of medication that blocks the action of a chemical called acetylcholine (a neurotransmitter). They can help treat a variety of conditions (such as urinary incontinence and COPD), and can also help with nausea and vomiting.

Scopolamine (Maldemar, Scopace, Transderm Scop®) is the main anticholinergic drug used for vomiting. Doctors use it to:

• Prevent `PONV` (post-operative vomiting).
• To prevent or treat nausea caused by ``motion sickness`` (vomiting while traveling).

5. Neurokinin-1 receptor antagonists

Neurokinin-1 (NK-1) receptor antagonists work by blocking a natural substance in your brain called neurokinin that causes nausea and vomiting. These medications are very effective in treating CINV (cancer-induced nausea) and PONV (post-operative nausea). They also have anti-anxiety (anxiolytic) and antidepressant properties.

Medicines in this category are:

• `Aprepitant (Aponvie®, Emend®` and `Cinvanti®)`
• `Fosaprepitant (Emend®` and `Focinvez®)`
• `Netupitant` and `palonosetron` combination (`Akynzeo®)`
• `Rolapitant (Varubi®)`

6. Dopamine antagonists

Dopamine antagonists are a type of medication that stops certain types of cells in your brain from firing. They are a mainstay of treatment for some mental health conditions and symptoms, especially psychosis and schizophrenia . However, some of these types can also help with nausea and vomiting.

There are several types of dopamine antagonists that are used for vomiting:

• `Amisulpride (Barhemsys®)`
• ``Chlorpromazine (Thorazine®)''
• `Droperidol (Inapsine®)`
• `Haloperidol (Haldol®)`
• `Metoclopramide (Reglan®, Gimoti®)`
• ``Olanzapine (Zyprexa®, Lybalvi®, Symbyax®)`
• `Prochlorperazine (Compro®)`

Dopamine antagonists are an alternative for `CINV` (cancer-induced vomiting) when other `(Antiemetic)` medications are ineffective. They can also help prevent `PONV` (post-operative vomiting).

7. Cannabinoids

Cannabinoids are a class of compounds found in the cannabis plant (marijuana). They bind to cannabinoid receptors in your brain, gastrointestinal system, and immune cells.

Manufactured cannabinoids are molecules that are designed to mimic the effects of tetrahydrocannabinol (THC). There are currently two types of synthetic cannabinoids on the market for use as antiemetics:

• `Dronabinol (Marinol®)`
• `Nabilone (Cesamet®)`

These are FDA-approved for CINV (cancer treatment-induced vomiting), and should only be used if first-line antiemetics have failed.

Cannabinoids are the newest type of antiemetic. Researchers are still learning and researching how they work.

How do we get this medicine? (Methods of administration)

Many ``Antiemetic`` medications are available in more than one ``form``. They may look like this:

• Oral pills, meaning pills that are swallowed or chewed.
• IV (intravenous) solutions, which are liquid medications given into a vein.
• Injections into your muscle (intramuscular).
• Skin patches (transdermal) – This is mainly for Scopolamine (an anticholinergic).
• Rectal pills (suppositories).

Can these medications cause side effects?

The side effects that can occur with each type of `(Antiemetic)` vary. Your doctor will tell you about these side effects before you start taking the medicine. Don't be afraid to ask questions and share your thoughts. If you have any bothersome side effects after starting an `(Antiemetic)`, talk to your doctor.

Here are some of the most common (but not all) side effects that can occur with each type of ``Antiemetic'':

• Serotonin antagonists: Headache, dizziness, and constipation.
• Antihistamines: Drowsiness.
• Glucocorticoids: Insomnia, excitation, and mood changes.
• Anticholinergics: Dry mouth, vision changes, and drowsiness.
• NK-1 receptor antagonists: May cause headaches, dizziness, and in some people, severe allergic reactions (anaphylaxis).
• Dopamine antagonists: dizziness, headache, and movement problems, such as dystonia (involuntary muscle contractions) and tardive dyskinesia (involuntary body movements, especially of the face and mouth).
• Cannabinoids:Vertigo, low blood pressure, and dysphoria (a feeling of great discomfort or dissatisfaction).

Is it okay to take this medicine if I am pregnant?

If you are suffering from nausea and vomiting during pregnancy, you should talk to your obstetrician-gynecologist (Ob/Gyn) or another doctor. They will often recommend making changes to the foods you eat or the times you eat them. If that doesn't help, they may prescribe medication.

Many studies have shown that some antiemetic medications are generally safe to use during pregnancy. However, the safety information for others is conflicting or limited. You and your doctor will decide together what is best for you.

As soon as you find out you're pregnant, see a doctor to discuss the medications you're taking. Also, you should definitely talk to a doctor before starting any new medication during pregnancy.

What do you do if you miss a dose of medication?

If you miss a dose of an ``Antiemetic'' medication, especially if it's a medication that prevents nausea and vomiting that can persist, like ``CINV,'' talk to your doctor. He or she will advise you on what to do.

What is the message we want to take home from this article?

No one likes to experience nausea and vomiting. Sometimes, these uncomfortable experiences are necessary for our bodies. But other times, they can be seriously harmful. Fortunately, antiemetic medications can help prevent and/or treat nausea and vomiting, whether it's early or ongoing. There are several options to choose from. Together, you and your doctor will decide what's best for you. So, if you're having this problem, don't be afraid to talk to a doctor, okay?

`Antiemetics, nausea, vomiting, antiemetics, side effects, pregnancy, cancer treatment