Ondansetron is a drug that is used to prevent and treat nausea and vomiting can caused by side effects chemotherapy, radiotherapy, or operation. This medicine can only consumedwith a doctor's prescription.
Ondansetron works by blocking serotonin binding to 5HT receptors3, so that it makes users not nauseous and stop vomiting. Ondansetron is available in the form of 4 mg and 8 mg tablets, film-coated tablets, syrup, suppositories, and injections.
Ondansetron trademark: Ondane, Ondansetron hydrochloride dihydrate, Glotron, Narfoz 8, Narfoz 4, Ondansetron HCL, Ondacap, and Dansefion.
What's that Ondansetron?
| group | Antiemetic |
| Category | Prescription drugs |
| Benefit | Prevent and treat nausea and vomiting. |
| Consumed by | Adults and children over the age of 6 months |
| Ondansetron for pregnant and lactating women | Category B: Studies in animal studies have not shown any risk to the fetus, but there are no controlled studies in pregnant women. It is not known whether ondansetron can be absorbed into breast milk or not. If you are breastfeeding, do not use this medicine before consulting your doctor first. |
| Drug form | Tablets, syrups, injections, and suppositories. |
Warning Before Using Ondansetron
- Tell your doctor if you have a history of allergies, especially to ondacentron or to other serotonin-blocking drugs, such as granisetron.
- Tell your doctor if you have an irregular heart rhythm, liver disease, indigestion, or have recently had stomach surgery.
- Tell your doctor if you are taking any medicines, supplements, or herbal medicines.
- Do not drive or operate a vehicle or perform activities that require alertness while taking ondansetron because this medicine can cause dizziness and drowsiness.
- In case of an allergic reaction to the drug or an overdose, see a doctor immediately.
Dosage and Rules of Use Ondansetron
The dosage of ondansetron varies, depending on the dosage form of the drug and the type of disease that causes nausea and vomiting.
Prevent nausea and vomiting due to radiotherapy
The doses of ondansetron in the form of oral drugs for adult patients are:
- Total radiotherapy: 8 mg, taken 1-2 hours before radiotherapy.
- High-dose abdominal radiotherapy: 8 mg, taken 1-2 hours before therapy, then every 8 hours for 1-2 days after therapy.
- Daily abdominal radiotherapy: 8 mg, taken 1-2 hours before radiotherapy, then every 8 hours after radiotherapy.
Dosage of injectable ondansetron for adult and elderly patients:
- Adult: 8 mg, injected slowly through a vein (intravenous) or through a muscle (intramuscularly) just before radio
- Elderly over the age of 75 years: the initial dose is 8 mg, injected intravenously over 15 minutes. The follow-up dose is 8 mg, every 4 hours.
For ondansetron in the form of suppositories (inserted through the rectum), the adult dose is 16 mg, given 1-2 hours before radiotherapy.
Prevent nausea and vomiting due to chemotherapy
The dosage of ondansetron in oral dosage form for adult patients and children aged 12 years and over is:
- Chemotherapy with usual emetogenic (nausea-inducing) effect: 8 mg, given 30 minutes to 2 hours before chemotherapy, then again 8-12 hours thereafter for 8 mg.
- Chemotherapy with severe emetogenic effects: 24 mg single dose, given 30 minutes to 2 hours before chemotherapy.
The dosage of ondansetron in oral dosage form for pediatric patients aged 4-11 years is:
- Chemotherapy with ordinary emetogenic effects: 4 mg, given 30 minutes before chemotherapy. The drug will be given again 4 hours and 8 hours after the initial dose.
The dose of injectable ondansetron for adult patients is:
- Chemotherapy with usual emetogenic effect: 8 mg intravenously or 0.15 mg/kg body weight intravenously. The drug is injected slowly as a single dose.
- Chemotherapy with severe emetogenic effect: 8 mg intravenously or intramuscularly. The drug is injected slowly as a single dose before chemotherapy. The maintenance dose can be given by infusion of 1 mg/hour for 24 hours, or by injection of 8 mg every 4 hours.
The dose of ondansetron injection for elderly patients is:
- Elderly less than 75 years: maximum dose 16 mg, intravenously. The drug is injected slowly over at least 15 minutes.
- Elderly over 75 years: initial dose 8 mg, intravenously. The follow-up dose is 8 mg, every 4 hours.
The dose of ondansetron injection for children over the age of 6 months is:
- 0.15 mg/kgBW with a maximum dose of 8 mg via intravenous injection, 30 minutes before chemotherapy. The dose can be repeated 4 and 8 hours after the initial dose.
Overcoming nausea and vomiting after surgery
- Adult patients: 4 mg by intravenous or intramuscular injection before anesthesia or after surgical procedures.
- Children weighing more than 40 kg: 4 mg by intravenous injection before administration of anesthesia. The maximum dose is 4 mg.
- Infants and children weighing less than 40 kg: 0.1 mg/kgBW, given by intravenous injection 1 hour before
Prevent delayed nausea and vomiting after chemotherapy
The dose of ondansetron in oral dosage forms for adult patients is 8 mg, 2 times a day, for 5 days. For suppositories, the adult dose is 16 mg, once daily, for 5 days after therapy.
How to Use Ondansetron Correctly
Be sure to read the instructions on the medicine package and follow the doctor's recommendations when taking ondansetron.
To prevent and treat nausea and vomiting due to chemotherapy and radiotherapy, the doctor will prescribe this drug approximately 1 hour before therapy is carried out. After that, you need to continue using ondansterone for a few days afterward as directed by your doctor.
In dealing with nausea and vomiting after surgery, this drug needs to be given approximately 1 hour before surgery. This drug will react 1-2 hours after consumption.
This medicine can be taken with or without food. Usually doctors will forbid patients to eat before chemotherapy, radiotherapy, or surgery. Ondansetron is not a type of drug that is chewed or swallowed, but dissolves on the surface of the tongue.
For patients who forget to take ondansetron, it is advisable to do so immediately if the interval with the next consumption schedule is not too close. If it is close, ignore it and do not double the dose.
To insert a suppository preparation, clean your hands first. Position yourself with one leg on a chair, or lie on your side. Next, insert the pointed end of the suppository into the anus, about 2-3 cm deep.
Ondansetron Interactions with Other Drugs
Some drugs can interact with ondansetron. Interactions that can arise from the use of ondansetron with other drugs are:
- Decreased effectiveness of pain relievers, such as tramadol.
- Decreased blood levels of ondansetron when used with rifampicin and other CYP3A4 stimulant drugs.
- Increased hypotensive effect and loss of consciousness when used together
- Prolongs the QT interval and increases the risk of arrhythmias, if used with drugs that have a QT prolonging effect, eg antiarrhythmic drugs, such as amiodarone and atenolol.
Recognize the Side Effects and Dangers of Ondansetron
Ondansetron can cause different side effects in each person. Some of the common side effects include:
- Headache
- Constipation
- Tired and weak
- happy
- Sleepy
- Dizzy
Check with your doctor if the side effects mentioned above last for a long time. You also need to go to the doctor or emergency room immediately if you experience an allergic reaction to the drug or some of the following complaints:
- Vision becomes blurry or completely lost.
- Painful
- Muscle cramps or stiffness.
- Chest pain.
- Hard to breathe.
- Fever.