Types of anti sickness medicines

Metoclopramide works by blocking the vomiting centre. It also acts directly on the wall of the gut. It encourages the stomach to empty its contents into your bowel.

Metoclopramide helps to get rid of the heavy feeling that you can have when you feel sick.

You can have metoclopramide as:

• a tablet

• a liquid

• an injection

You usually take it for up to 5 days.

Prochlorperazine belongs to the group of medicines called phenothiazines. Phenothiazines medicines act by blocking the vomiting centre in the brain.

You can have prochlorperazine:

• as a tablet

• as an injection into the muscle

• a tablet that dissolves when you put it between your gum and upper lip

Another medicine in the phenothiazine group is chlorpromazine. This tends to make you drowsy so it's used less often.

Domperidone is like metoclopramide, it speeds up the emptying of your stomach. It also acts on a part of your brain called the chemoreceptor trigger zone. It works well for sickness from various causes.

You usually take domperidone for up to a week.

These medicines block receptors in the gut and brain that send messages to the chemoreceptor trigger zone and the vomiting centre. They are also called 5HT3 blockers.

Serotonin blockers work very well for some types of sickness. They work best when you have steroids at the same time.

There are several medicines in this group, including:

• ondansetron (Zofran)

• granisetron (Kytril)

• palonosetron (Aloxi)

These medicines come as tablets or injections. Ondansetron is also available as a tablet that melts on your tongue. Granisetron also comes as a patch you put on your skin.

Some anti anxiety medicines can reduce sickness. Lorazepam is the medicine from this group that you are most likely to have for chemotherapy sickness. You usually have it with other types of anti sickness medicine. 

You might have lorazepam to help treat sickness before treatment (anticipatory nausea and vomiting). In this case, you might take it the evening before and the morning of your chemotherapy.

Cyclizine is an antihistamine that you might have for sickness.

It dissolves easily and mixes safely with other medicines in a syringe pump. This can help if you find swallowing difficult for any reason.

Steroids can help to control sickness. They can help particularly with sickness from:

• increased pressure in the skull (from a brain tumour or secondary cancer in the brain)

• a blockage in the gut

• some types of chemotherapy (when used with other anti sickness medicines)

Steroids reduce swelling so they can help to lower pressure in the skull, which causes sickness.

They might reduce swelling around a tumour blocking the gut and help to allow fluids to pass through. This relieves the vomiting that a bowel obstruction can cause. Steroids will only work for a limited time. But they might help until you have other treatment. Or, they can help to make you more comfortable.

Dexamethasone is a steroid that you could have as an injection into a vein just before chemotherapy. You might have steroid tablets to take at home for a couple of days after chemotherapy. 

Dexamethasone can cause difficulty with sleeping and so it’s better if you take it before lunchtime.

Find out more about steroids including possible side effects

Blockages in the gut might mean you have medicines to reduce the amount of liquid in your intestines. These medicines encourage the body to reabsorb fluids from the digestive system. This reduces the build up of fluid above the blockage. You won't feel so sick or need to be sick as often if there is less of a build up. 

Buscopan (hyoscine butylbromide) reduces fluid in the intestines and is an anti spasm (cramps) medicine. It helps to reduce cramps by relaxing the smooth muscle in the bowel and slowing down the movement of the bowel.

Octreotide (Sandostatin) can help to relieve the sickness you get from a blockage in the gut by reducing the amount of liquid produced in the bowel.

Nabilone is a medicine developed from cannabis (marijuana). It is licensed for treating severe sickness from chemotherapy that is not controlled by other anti sickness medicines.

It works very well for some people, but can cause drowsiness or dizziness in others. These side effects can last for a couple of days after you've stopped taking it.

Find out more about medical cannabis

Aprepitant (Emend) is a newer medicine which works by blocking a substance in the body called neurokinin. You might have it with steroids and serotonin blockers to help control sickness caused by chemotherapy.

You take a tablet one hour before chemotherapy and then one tablet a day for the next 2 days.

Fosaprepitant (Ivemend) is a similar medicine to aprepitant. It’s only available as an injection into the bloodstream.

Sedatives can help to control sickness. Some anti psychotic medicines such as levomepromazine (Nozinan) can also help to control sickness but may make you drowsy unless they are used at a low dose. This can be a helpful effect if you take them at night.

Haloperidol (Haldol) is another sedative that is particularly good for sickness due to medicines. So, doctors often use it for sickness related to morphine. It is also used for sickness related to:

• high blood calcium levels (hypercalcaemia)

• kidney or liver failure

• a blocked bowel

Olanzapine helps to manage symptoms of some mental health conditions. It is also called an anti psychotic medicine. It can help to control sickness from chemotherapy alongside ondansetron and steroids.

You have olanzapine as a tablet or as a tablet that melts on your tongue.

Olanzapine can make you drowsy. Your team may be able to reduce your dose if this happens.