What is the recommended dosage of ondansetron for chemotherapy-induced nausea and vomiting. How should ondansetron be administered for postoperative nausea and vomiting. What are the dosing guidelines for ondansetron in pediatric patients. How does ondansetron dosage differ for various types of radiotherapy.

Understanding Ondansetron: A Powerful Antiemetic Medication

Ondansetron is a widely used antiemetic medication that plays a crucial role in managing various types of nausea and vomiting. As a healthcare professional, it’s essential to have a thorough understanding of its dosage guidelines and administration methods to ensure optimal patient care.

Dosage Guidelines for Chemotherapy-Induced Nausea and Vomiting in Adults

When it comes to managing chemotherapy-induced nausea and vomiting (CINV), ondansetron dosage varies depending on the emetogenicity of the chemotherapy regimen.

Highly Emetogenic Chemotherapy (HEC)

For patients undergoing highly emetogenic chemotherapy, such as cisplatin doses of 50 mg/m2 or greater, the recommended oral dose is 24 mg. This should be administered 30 minutes before the start of single-day HEC.

Moderately Emetogenic Chemotherapy (MEC)

For moderately emetogenic chemotherapy, the dosing regimen is as follows:

• Initial dose: 8 mg orally, 30 minutes before the start of chemotherapy
• Subsequent dose: 8 mg orally, 8 hours after the first dose
• Maintenance: 8 mg orally twice daily (every 12 hours) for 1 to 2 days after completing chemotherapy

Is there a difference in ondansetron administration for intravenous chemotherapy? Yes, for intravenous administration, the recommended dose is 0.15 mg/kg. The first dose should be infused over 15 minutes, 30 minutes before the start of emetogenic chemotherapy. Subsequent doses are given 4 and 8 hours after the first dose. It’s important to note that the maximum dose per administration should not exceed 16 mg.

Ondansetron for Postoperative Nausea and Vomiting in Adults

Postoperative nausea and vomiting (PONV) can significantly impact patient recovery. Ondansetron offers an effective solution for preventing this common complication.

Oral Administration

For oral administration, the recommended dose is 16 mg, taken 1 hour before the induction of anesthesia.

Intravenous Administration

When administering ondansetron intravenously for PONV, the recommended dose is 4 mg. This should be given undiluted, either immediately before the induction of anesthesia or postoperatively if nausea and/or vomiting occur within 2 hours after surgery.

Can ondansetron be administered intramuscularly for PONV? Yes, an alternative route is intramuscular injection, with the same 4 mg dose given undiluted.

Ondansetron Dosage for Radiation-Induced Nausea and Vomiting

Radiation therapy can also cause significant nausea and vomiting. The ondansetron dosage for radiation-induced nausea and vomiting varies based on the type of radiotherapy.

General Radiotherapy

For general radiotherapy-induced nausea and vomiting, the recommended dose is 8 mg orally, taken three times a day.

Total Body Irradiation

In cases of total body irradiation, patients should take 8 mg orally 1 to 2 hours before each fraction of radiotherapy administered daily.

Single High-dose Fraction Radiotherapy to the Abdomen

For this type of radiotherapy, the dosing regimen is as follows:

• Initial dose: 8 mg orally, 1 to 2 hours before radiotherapy
• Subsequent doses: 8 mg orally every 8 hours after the first dose
• Duration: Continue for 1 to 2 days after completing radiotherapy

Daily Fractionated Radiotherapy to the Abdomen

The dosing schedule for daily fractionated radiotherapy to the abdomen is:

• Initial dose: 8 mg orally, 1 to 2 hours before radiotherapy
• Subsequent doses: 8 mg orally every 8 hours after the first dose
• Duration: Continue daily for each day radiotherapy is administered

Pediatric Dosing Guidelines for Ondansetron

Ondansetron is also effective in managing nausea and vomiting in pediatric patients. However, dosing guidelines differ from those for adults.

Postoperative Nausea and Vomiting in Children

For children aged 1 month to 12 years, the dosage is weight-based:

• Less than 40 kg: 0.1 mg/kg IV over 2 to 5 minutes
• 40 kg and greater: 4 mg IV over 2 to 5 minutes

This dose should be administered immediately before or after anesthesia induction, or postoperatively if nausea and/or vomiting occur shortly after surgery.

Chemotherapy-Induced Nausea and Vomiting in Children

For children aged 4 to 11 years undergoing chemotherapy, the recommended oral dose is 4 mg, given three times a day. The first dose should be administered 30 minutes before the start of chemotherapy, with subsequent doses given 4 and 8 hours after the first dose.

Special Considerations and Precautions

While ondansetron is generally well-tolerated, there are some important considerations for its use:

• Renal and hepatic impairment: No specific dose adjustments are recommended for patients with renal or hepatic dysfunction. However, close monitoring is advised.
• Elderly patients: No dosage adjustment is necessary for elderly patients.
• Pregnancy: Ondansetron should be used during pregnancy only if clearly needed, as its safety in pregnant women has not been established.
• Breastfeeding: Caution is advised when administering ondansetron to nursing mothers, as it is excreted in human milk.

Are there any drug interactions to be aware of when prescribing ondansetron? Yes, ondansetron may interact with several medications, including:

• Apomorphine: Concomitant use may cause severe hypotension and loss of consciousness
• QT interval-prolonging drugs: Combined use may increase the risk of QT interval prolongation
• Serotonergic drugs: Concomitant use may increase the risk of serotonin syndrome

Maximizing the Efficacy of Ondansetron Treatment

To ensure the best outcomes for patients receiving ondansetron, consider the following tips:

1. Timing is crucial: Administer ondansetron at the recommended times relative to the emetogenic event (chemotherapy, surgery, or radiation) for optimal efficacy.
2. Monitor for side effects: While generally well-tolerated, be vigilant for potential side effects such as headache, constipation, or dizziness.
3. Educate patients: Provide clear instructions on how and when to take ondansetron, especially for outpatient regimens.
4. Consider combination therapy: In some cases, combining ondansetron with other antiemetics may provide better control of nausea and vomiting.
5. Stay informed: Keep up-to-date with the latest research and guidelines on antiemetic therapy to provide the best possible care.

How can healthcare providers ensure proper administration of ondansetron? It’s essential to follow these guidelines:

• For intravenous administration, dilute the injection formulation before use.
• Adhere to the maximum dose limits, particularly for intravenous administration (16 mg per dose).
• Be aware that multi-day, single-dose administration of 24 mg orally for HEC has not been studied and should be avoided.
• For postoperative nausea and vomiting, note that administering a second dose does not provide additional control.

Future Directions in Antiemetic Therapy

As our understanding of nausea and vomiting mechanisms continues to evolve, so too does the landscape of antiemetic therapy. Researchers are exploring several promising avenues for improving the management of nausea and vomiting:

Novel Drug Formulations

Scientists are investigating new formulations of ondansetron and other antiemetics to improve their efficacy and ease of administration. These include:

• Long-acting injectable formulations
• Transdermal patches for sustained drug release
• Nasal sprays for rapid onset of action

Personalized Medicine Approaches

Genetic factors can influence an individual’s response to antiemetic therapy. Researchers are exploring pharmacogenomic approaches to tailor antiemetic regimens based on a patient’s genetic profile, potentially improving efficacy and reducing side effects.

Combination Therapies

While ondansetron is often used in combination with other antiemetics, ongoing research is identifying optimal combination strategies for different patient populations and emetogenic stimuli.

Non-Pharmacological Interventions

Complementary approaches to managing nausea and vomiting are gaining attention. These include:

• Acupuncture and acupressure
• Mindfulness and relaxation techniques
• Virtual reality interventions

How might these advancements impact the future use of ondansetron? While ondansetron is likely to remain a cornerstone of antiemetic therapy, these developments may lead to more personalized and comprehensive approaches to managing nausea and vomiting.

Ondansetron in the Context of Overall Patient Care

While ondansetron is a powerful tool in managing nausea and vomiting, it’s important to consider its use within the broader context of patient care. Here are some key considerations:

Patient Quality of Life

Effective management of nausea and vomiting can significantly improve a patient’s quality of life, particularly for those undergoing chemotherapy or radiation therapy. By controlling these symptoms, ondansetron can help patients maintain their nutritional status, adhere to treatment regimens, and engage in daily activities.

Cost-Effectiveness

When prescribing ondansetron, it’s important to consider the cost-effectiveness of different formulations and regimens. Generic versions of ondansetron are available, which can help reduce treatment costs without compromising efficacy.

Patient Education and Empowerment

Educating patients about ondansetron and its proper use is crucial for treatment success. This includes:

• Explaining the importance of taking the medication as prescribed
• Discussing potential side effects and when to seek medical attention
• Providing strategies for managing breakthrough nausea and vomiting

Multidisciplinary Approach

Optimal management of nausea and vomiting often requires a multidisciplinary approach. This may involve collaboration between oncologists, anesthesiologists, pharmacists, nurses, and supportive care specialists to develop comprehensive antiemetic strategies.

How can healthcare providers ensure a holistic approach to nausea and vomiting management? Consider these strategies:

• Regularly assess the effectiveness of the antiemetic regimen and adjust as needed
• Address other factors that may contribute to nausea and vomiting, such as pain, anxiety, or gastrointestinal issues
• Incorporate supportive care measures, such as dietary modifications and hydration management
• Encourage open communication with patients about their symptoms and concerns

Conclusion and Key Takeaways

Ondansetron is a versatile and effective antiemetic medication with applications in managing chemotherapy-induced, postoperative, and radiation-induced nausea and vomiting. Its efficacy across various patient populations and emetogenic stimuli makes it an invaluable tool in modern medicine.

Key points to remember include:

• Dosage and administration methods vary based on the specific indication and patient characteristics
• Proper timing of ondansetron administration is crucial for optimal efficacy
• Pediatric dosing differs from adult dosing and is often weight-based
• While generally well-tolerated, healthcare providers should be aware of potential drug interactions and side effects
• Ondansetron is most effective when used as part of a comprehensive approach to patient care

As research in antiemetic therapy continues to advance, healthcare providers should stay informed about new developments and guidelines to provide the best possible care for their patients. By mastering the use of ondansetron and staying attuned to patient needs, clinicians can significantly improve the quality of life and treatment outcomes for individuals experiencing nausea and vomiting.

Ondansetron Dosage Guide + Max Dose, Adjustments

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Medically reviewed by Drugs.com. Last updated on Nov 28, 2022.

Applies to the following strengths: 4 mg/5 mL; 32 mg/50 mL-D5%; 2 mg/mL; 4 mg; 8 mg; 24 mg; 32 mg/50 mL-NaCl 0.9%

Usual Adult Dose for:

• Nausea/Vomiting – Chemotherapy Induced
• Nausea/Vomiting
• Nausea/Vomiting – Postoperative
• Nausea/Vomiting – Radiation Induced

Usual Pediatric Dose for:

• Nausea/Vomiting – Postoperative
• Nausea/Vomiting – Chemotherapy Induced

Additional dosage information:

• Renal Dose Adjustments
• Liver Dose Adjustments
• Precautions
• Dialysis
• Other Comments

Usual Adult Dose for Nausea/Vomiting – Chemotherapy Induced

Oral:
Highly Emetogenic Cancer Chemotherapy (HEC):

• Recommended dose: 24 mg orally 30 minutes before the start of single-day HEC (including cisplatin doses of 50 mg/m2 or greater)

Moderately Emetogenic Cancer Chemotherapy (MEC):

• Recommended dose: 8 mg orally twice a day, with the first dose administered 30 minutes before the start of chemotherapy and the subsequent dose 8 hours later; then 8 mg orally 2 times a day (every 12 hours) for 1 to 2 days after the completion of chemotherapy

Parenteral:

• Recommended dose: 0. 15 mg/kg IV, with the first dose (infused over 15 minutes) 30 minutes before the start of emetogenic chemotherapy and subsequent doses given 4 and 8 hours after the first dose.
• Maximum dose: 16 mg per dose

Comments:

• Multi-day, single-dose administration of 24 mg orally for HEC has not been studied.
• The injection formulation should be diluted prior to IV administration.

Uses:

• Prevention of nausea and vomiting associated with HEC or MEC
• Prevention of nausea and vomiting associated with initial and repeat courses of emetogenic chemotherapy

Usual Adult Dose for Nausea/Vomiting

Oral:
Highly Emetogenic Cancer Chemotherapy (HEC):

• Recommended dose: 24 mg orally 30 minutes before the start of single-day HEC (including cisplatin doses of 50 mg/m2 or greater)

Moderately Emetogenic Cancer Chemotherapy (MEC):

• Recommended dose: 8 mg orally twice a day, with the first dose administered 30 minutes before the start of chemotherapy and the subsequent dose 8 hours later; then 8 mg orally 2 times a day (every 12 hours) for 1 to 2 days after the completion of chemotherapy

Parenteral:

• Recommended dose: 0. 15 mg/kg IV, with the first dose (infused over 15 minutes) 30 minutes before the start of emetogenic chemotherapy and subsequent doses given 4 and 8 hours after the first dose.
• Maximum dose: 16 mg per dose

Comments:

• Multi-day, single-dose administration of 24 mg orally for HEC has not been studied.
• The injection formulation should be diluted prior to IV administration.

Uses:

• Prevention of nausea and vomiting associated with HEC or MEC
• Prevention of nausea and vomiting associated with initial and repeat courses of emetogenic chemotherapy

Usual Adult Dose for Nausea/Vomiting – Postoperative

Oral:

• Recommended dose: 16 mg orally 1 hour before the induction of anesthesia

Parenteral:

• Recommended dose: 4 mg IV (undiluted) immediately before induction of anesthesia or postoperatively (nausea and/or vomiting within 2 hours after surgery)
• Alternative route: 4 mg IM (undiluted)

Comment:

• Administration of a second dose does not provide additional control of nausea and vomiting.

Use:

• Prevention of postoperative nausea and vomiting

Usual Adult Dose for Nausea/Vomiting – Radiation Induced

Recommended dose: 8 mg orally 3 times a day

• Total Body Irradiation: 8 mg orally 1 to 2 hours before each fraction of radiotherapy administered each day
• Single High-dose Fraction Radiotherapy to the Abdomen: 8 mg orally 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for 1 to 2 days after the completion of radiotherapy
• Daily Fractionated Radiotherapy to the Abdomen: 8 mg orally 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for each day radiotherapy is given

Use:

• Prevention of nausea and vomiting associated with radiotherapy, either as total body irradiation, single high-dose fraction, or daily fractions to the abdomen

Usual Pediatric Dose for Nausea/Vomiting – Postoperative

Parenteral:
1 month to 12 years:
Less than 40 kg:

• Recommended dose: 0. 1 mg/kg IV over 2 to 5 minutes immediately prior to/following anesthesia induction or postoperatively (nausea and/or vomiting occurring shortly after surgery)

40 kg and greater:

• Recommended dose: 4 mg IV over 2 to 5 minutes immediately prior to/following anesthesia induction or postoperatively (nausea and/or vomiting occurring shortly after surgery)

Use:

• Prevention of postoperative nausea and vomiting

Usual Pediatric Dose for Nausea/Vomiting – Chemotherapy Induced

Oral:
4 to 11 years:

• Recommended dose: 4 mg orally 3 times a day, with the first dose administered 30 minutes before the start of chemotherapy, and subsequent doses 4 and 8 hours after the first dose; then 4 mg orally 3 times a day (every 8 hours) for 1 to 2 days after the completion of chemotherapy

12 years and older:

• Recommended dose: 8 mg orally twice a day, with the first dose administered 30 minutes before the start of chemotherapy and the subsequent dose 8 hours later; then 8 mg orally 2 times a day (every 12 hours) for 1 to 2 days after the completion of chemotherapy

Parenteral:
6 months to 18 years:

• Recommended dose: 0. 15 mg/kg IV, with the first dose (infused over 15 minutes) 30 minutes before the start of emetogenic chemotherapy, and subsequent doses given 4 and 8 hours after the first dose
• Maximum dose: 16 mg (per dose)

Comments:

• The injection formulation should be diluted in 50 mL prior to IV administration.
• This drug should be used to prevent nausea and vomiting associated with moderately to highly emetogenic chemotherapy.

Uses:

• Prevention of nausea and vomiting associated with moderately emetogenic cancer chemotherapy
• Prevention of nausea and vomiting associated with initial and repeat courses of emetogenic chemotherapy

Renal Dose Adjustments

No adjustment recommended.

Liver Dose Adjustments

• Mild to moderate hepatic impairment (Child-Pugh less than 10): No adjustment recommended.
• Severe hepatic impairment: (Child-Pugh 10 or greater): 8 mg IV over 30 minutes before the start of emetogenic chemotherapy; maximum 8 mg per day

Precautions

Safety and efficacy have not been established in patients younger than 6 months (parenteral formulations) and 4 years (oral formulations).

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• Do not push oral dissolving tablets (ODTs) through the foil backing.
• ODT and film formulations should be used with dry hands and immediately placed on the tongue. The dosage form should dissolve in saliva. Administration with additional liquid is not necessary. In patients requiring multiple films per dose, each film should be allowed to completely dissolve before administering the next film.
• IV doses greater than 8 mg should be slowly injected over at least 15 minutes. Single IV doses greater than 16 mg should be avoided.
• IM doses should be administered undiluted at a rate slower than 30 seconds (e.g., 2 to 5 minutes).
• The suppository formulation is not recommended for use in children.

Storage requirements:

• The manufacturer product information should be consulted.

Reconstitution/preparation techniques:

• The manufacturer product information should be consulted.

IV compatibility:

• The manufacturer product information should be consulted.

General:

• The lowest effective dose should be used.
• Oral, rectal, IV, and IM routes have shown to be equally effective over the first 24 hours of chemotherapy.
• Use of the ODT formulation in the prevention of nausea and vomiting associated with highly-emetogenic chemotherapy, radiotherapy, or in postoperative situations has not been studied in pediatric patients.
• Concomitant use with dexamethasone may potentiate the antiemetic effects of this drug.
• Routine prophylaxis is not recommended for postoperative patients with little expectation of nausea and vomiting; however, use is recommended for patients who should avoid postoperative nausea and vomiting, even with low risk of postoperative nausea and vomiting.

Monitoring:

• Electrolyte levels, especially in patients at risk for hypomagnesemia or hypokalemia
• ECG, especially in patients with a history of QT prolongation, bradycardia, congestive heart failure, or those on drugs which could prolong the QT interval or result in electrolyte abnormalities
• Signs/symptoms of respiratory events or hypersensitivity reactions

Patient advice:

• Inform patients that this drug may cause drowsiness, and they should avoid driving or operating machinery until the full effects of the drug are seen.
• Patients should be advised to immediately report any signs/symptoms associated with serotonin syndrome or hypersensitivity reactions to their prescribers. Patients should also report lightheadedness, syncope episodes, or any perceived changes in heart rate.
• Advise patients to speak to their healthcare provider if they become pregnant, intend to become pregnant, or are breastfeeding.
• Tell patients to report all concurrent prescription and nonprescription medications or herbal products they are taking.

Frequently asked questions

• Can you take ondansetron while pregnant?

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Patient resources

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• Ondansetron injection
• Ondansetron (Injection) (Advanced Reading)
• Ondansetron (Oral, Oromucosal) (Advanced Reading)
• Ondansetron Oral Soluble Film

Other brands

Zofran, Zofran ODT, Zuplenz

Professional resources

• Prescribing Information

Related treatment guides

• Gastroenteritis
• Nausea/Vomiting
• Alcohol Use Disorder
• Nausea/Vomiting, Chemotherapy Induced

Further information

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Ondansetron Interactions Checker – Drugs.com

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There are 338 drugs known to interact with
ondansetron, along with
2 disease interactions.

Of the total drug interactions,
122 are major, 212 are moderate, and 4 are minor.

Does ondansetron interact with my other drugs?

Enter other medications to view a detailed report.

• View all 338 medications that may interact with ondansetron
• View ondansetron disease interactions (2)

Most frequently checked interactions

View interaction reports for ondansetron and the medicines listed below.

• Major
• Moderate
• Minor
• Unknown

• Adderall (amphetamine / dextroamphetamine)
• Aspirin Low Strength (aspirin)
• Benadryl (diphenhydramine)
• Cymbalta (duloxetine)
• Eliquis (apixaban)
• Fish Oil (omega-3 polyunsaturated fatty acids)
• Flexeril (cyclobenzaprine)
• Flonase (fluticasone nasal)
• Lexapro (escitalopram)
• Linzess (linaclotide)
• Lyrica (pregabalin)
• Metoprolol Succinate ER (metoprolol)
• Metoprolol Tartrate (metoprolol)
• MiraLAX (polyethylene glycol 3350)
• Nexium (esomeprazole)
• Norco (acetaminophen / hydrocodone)
• Paracetamol (acetaminophen)
• ProAir HFA (albuterol)
• Probiotic Formula (bifidobacterium infantis / lactobacillus acidophilus)
• Singulair (montelukast)
• Symbicort (budesonide / formoterol)
• Synthroid (levothyroxine)
• Tylenol (acetaminophen)
• Ventolin HFA (albuterol)
• Vitamin B12 (cyanocobalamin)
• Vitamin C (ascorbic acid)
• Vitamin D2 (ergocalciferol)
• Vitamin D3 (cholecalciferol)
• Xanax (alprazolam)
• Zyrtec (cetirizine)

Ondansetron disease interactions

There are 2 disease interactions with ondansetron which include:

• QT interval prolongation
• liver disease

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More about ondansetron

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• Drug images
• Side effects
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• Drug class: 5HT3 receptor antagonists
• Breastfeeding

Related treatment guides

• Gastroenteritis
• Nausea/Vomiting
• Alcohol Use Disorder
• Nausea/Vomiting, Chemotherapy Induced

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.

Major	Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate	Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor	Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown	No interaction information available.

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Ondansetron PJSC SPC “Borshchagovsky CPP”

• Pharmacological properties
• Indications Ondansetron
• Application of Ondansetron
• Contraindications
• Side effects
• Special instructions
• Interactions
• Overdose
• Storage conditions
• Diagnosis
• Recommended alternatives
• Trade names

Pharmacodynamics. Antiemetic. The mechanism of action is due to a competitive highly selective blockade of central and peripheral 5HT ₃ serotonin receptors (receptors of the trigger zone, vomiting center). Suppresses the gag reflex, eliminating and preventing nausea when using cytotoxic chemotherapeutic agents, radiation therapy, in the postoperative period. With repeated use, it slows down peristalsis and the passage of contents through the intestines.

Pharmacokinetics. When administered intravenously at a dose of 0.15 mg/kg of body weight to adults under the age of 75 years, C _max in blood plasma averages about 100 ng/ml, in persons over the age of 75 years – 170 ng/ml . With an IV infusion of 32 mg for 15 minutes, C _max reaches 264 ng / ml. With the / m administration of C _max ondansetron in blood plasma (about 25 ng / ml) is noted 10 minutes after injection.

When taken orally, the drug is well absorbed in the gastrointestinal tract, bioavailability is about 60% due to the effect of the first passage through the liver. C _max of ondansetron in plasma is reached after 1.5–1.7 hours. Eating prolongs the absorption period by 17% without affecting C _max . Binding to plasma proteins – 70-76%.

The main part of the administered dose (85–90%) is hydroxylated in the liver with the participation of cytochrome P450 to indole ring compounds, and then conjugated with glucuronic and sulfuric acids. The total volume of distribution is 1.9 l / kg of body weight, T _½ , depending on age, is 3.5–5.5 h, the total clearance is 5.9ml/(min kg). The drug is excreted from the body by the kidneys, while 5% of the administered dose is excreted unchanged. The pharmacokinetic parameters of ondansetron do not change with repeated use.

In children, as well as in persons with liver damage, the total clearance decreases, in elderly patients, T _½ and the total clearance of the drug increase. In patients with moderate renal insufficiency (creatinine clearance – 15-60 ml / min), systemic clearance and volume of distribution of ondansetron are reduced, resulting in a clinically insignificant small increase in T _½ drugs. In women, C _max and the bioavailability of the drug are higher, and the clearance and volume of distribution are lower than in men.

prevention and management of nausea and vomiting during cytotoxic chemotherapy (initial and repeated courses, including high dose cisplatin) and radiotherapy (whole body irradiation, partial single high-dose or daily abdominal irradiation) in oncology. Prevention and elimination of nausea and vomiting in the postoperative period in general surgery, ophthalmology, etc.

Tablets

When carrying out cytostatic therapy, the dosing regimen is set individually, depending on the severity of the emetic reaction.

Moderate emetogenic chemotherapy and radiotherapy

Adults and children over 12 years of age, by mouth: Initially 8 mg 1 to 2 hours before anticancer therapy, followed by another 8 mg 8 to 12 hours later. To prevent late or prolonged nausea and vomiting after the first 24 hours, the use of the drug should be continued at 8 mg every 12 hours. With partial high-dose irradiation of the abdominal region, 8 mg every 8 hours is prescribed. The drug is taken during the entire course of chemotherapy and radiation therapy, as well as 1-2 days (if necessary – 3-5 days) after its completion.

Highly emetogenic chemotherapy

Adults and children over 12 years of age are given ondansetron 24 mg orally (simultaneously with dexamethasone phosphate) 1 to 2 hours before starting chemotherapy. For the prevention of late vomiting in the following days, 8 mg 2 times a day during the entire course of chemotherapy, as well as 5 days after its completion.

In case of chemotherapy in children aged 4-12 years, it is prescribed orally: initially 4 mg 3 times a day (30 minutes before the start of the course, then after 4 and 8 hours). To prevent late vomiting, 4 mg is prescribed every 8 hours 1-2 days, then 4 mg 2 times a day during the entire course, as well as 5 days after its completion.

Postoperative nausea and vomiting

Adults and children over 12 years of age are given 16 mg 1 hour before anesthesia. Children under the age of 12 are not prescribed.

The maximum daily dose of ondansetron is 32 mg, for patients with severe hepatic impairment – 8 mg.

Injection solution

The preparation in the form of an injection solution can be administered IM or IV as a single slow injection or by infusion. To prepare the ondansetron solution for infusion, you can use 0.9% sodium chloride solution, 5% glucose solution, Ringer solution. Solution of ondansetron for infusion administration is prepared immediately before administration; however, if necessary, it can be stored until fully used for no more than 24 hours at a temperature of 2–8 °C. During the infusion, protection from light is not required (under normal lighting).

Emethogenic Chemotherapy and Radiation Therapy

For adults, administer 8 mg IV slowly immediately prior to chemotherapy.

Highly emetogenic chemotherapy

• a single dose of 8-32 mg given IV slowly immediately before chemotherapy; when administered at a dose above 8 mg, ondansetron must be dissolved in 50-100 ml of 0. 9% sodium chloride solution or other compatible solution for intravenous administration and an infusion should be carried out for at least 15 minutes;

• a dose of 8 mg is administered slowly IV just before the course of chemotherapy, then 2 IV doses of 8 mg slowly at a dose of 2-4 hours apart, or IV drip at a dose of 1 mg/hour for 24 hours.

The choice of dosing regimen is set individually depending on the severity of the emetogenic effect.

Children may be given a single IV dose of 5 mg/m ² immediately prior to chemotherapy.

Postoperative nausea and vomiting

Adults: 4 mg may be given as a slow IV or IM injection during induction of anesthesia. To eliminate the development of postoperative nausea and vomiting, a single injection of 4 mg intramuscularly or intravenously is recommended.

Children: may be given at a dose of 0.1 mg/kg body weight (maximum 4 mg) IV slowly before, during, or after initiation of anesthesia to prevent postoperative nausea and vomiting. To eliminate the development of postoperative nausea and vomiting, a single dose of 0.1 mg/kg (maximum 4 mg) intramuscularly or intravenously is recommended.

hypersensitivity to drug components; the period of pregnancy (especially the first trimester) and breastfeeding; insufficiency of liver function, surgical operations on the abdominal cavity; the drug is not prescribed to children under the age of 4 years during chemotherapy and radiation therapy; during anesthesia, tablets cannot be prescribed to children under the age of 12 years; injection solution – up to 2 years.

from the side of the central nervous system: headache, dizziness, temporary impairment of visual acuity (with rapid intravenous administration), spontaneous movement disorders, seizures, depression of the central nervous system, paresthesia, weakness, extrapyramidal symptoms, syncope;

from the side of the cardiovascular system: feeling of heat and flushing to the face, arrhythmia, tachycardia or bradycardia, arterial hypo- or hypertension;

from the digestive system: constipation, diarrhea, hiccups, dry mouth, transient increase in aminotransferase activity, liver failure;

allergic reactions: urticaria, bronchospasm, in isolated cases – anaphylactic reactions;

other: cough, chest pain (anginal type), redness and burning at the injection site.

Breast-feeding should be discontinued during treatment with Ondansetron.

For parenteral use of the drug in patients with moderate and severe hepatic impairment, it is not recommended to exceed a dose of 8 mg / day.

In the event of a very severe vomiting reaction as a result of chemotherapy, the effectiveness of the drug can be increased by a single intravenous administration of corticosteroids (for example, 20 mg of dexamethasone sodium phosphate) before starting chemotherapy.

Use with caution in patients with a history of hypersensitivity reactions to other selective serotonin 5HT ₃ receptor antagonists. With caution and under close medical supervision, the drug is used in the treatment of patients with signs of subacute intestinal obstruction.

Simultaneous use of inhibitors of microsomal hepatic enzymes of the cytochrome P450 system can increase T _½ and reduce the overall clearance of the drug.

with special use with inducers of microsomal hepatic enzymes of the P450 cytochrome system (barbiturates, carbamazepine, karizopoli, gluthetimide, Grisoofulvin, nitrogen oxide, papaverine, phenylbutazone, phenytoine, hydrantin, rifampicin, tolbutamide, it is possible to reduce clinical effects of clinical effect the drug.

The drug in the form of an infusion solution at a concentration of ondansetron 16-160 mcg / ml (8 mg / 500 ml – 8 mg / 50 ml) can be administered through a Y-shaped catheter in combination with the following drugs:

• cisplatin up to 0.48 mg/ml for 1-8 hours;

• carboplatin at a concentration of 0.18-9.90 mg / ml for 10-60 minutes;

• fluorouracil at concentrations up to 0.8 mg/ml at a rate of at least 20 ml/h, bearing in mind that higher concentrations of fluorouracil may cause precipitation of ondansetron;

• etoposide at a concentration of 0.14-0.25 mg / ml for 30-60 minutes;

• ceftazidime 0.025-2 g, diluted with water for injection according to manufacturer’s recommendations, as an IV bolus injection over 5 minutes;

• cyclophosphamide 0.1-1 g, diluted with water for injection according to manufacturer’s recommendations, as an IV bolus injection over 5 minutes;

• doxorubicin 10-100 mg, diluted with water for injection according to manufacturer’s recommendations, as an IV bolus injection over 5 minutes;

• Dexamethasone 20 mg IV slowly over 2-5 minutes in combination with 8-32 mg ondansetron in 50-100 ml solution.

The drug should not be used in the same syringe or in the same dropper with other drugs.

Overdose may cause side effects. Treatment is drug withdrawal and symptomatic therapy aimed at maintaining vital functions. There is no specific antidote.

tablets – in a dry, dark place at a temperature not exceeding 25 ° C; ampoules – in a place protected from light at a temperature not exceeding 25 °C. Shelf life – 2 years.

Use of ondansetron in the treatment of children with cancer

Supportive care

Trademarks:

Zofran®

Other names:

Ondansetron Hydrochloride

Often used for:

treatment of nausea and vomiting

Ondansetron is a drug that is used to prevent and treat nausea and vomiting during chemotherapy and radiation therapy, as well as in the postoperative period.

The breakdown rate of ondansetron in the body may vary. This is determined by the activity of an enzyme called P450 2D6 (CYP2D6). Genetic analysis may be required to determine the quality of the enzymes in a particular patient. The drug may not be effective enough if the rate of breakdown of ondansetron in the patient’s body is higher than normal.

This drug is usually taken 30 minutes before chemotherapy starts.

Oral administration in the form of tablets or absorbable films or tablets

Oral liquid form

Administered intravenously (by drip or injection) in liquid form

• Headache
• Pain in the abdomen
• Dizziness
• Diarrhea
• Constipation
• Rash
• Increased fatigue or general weakness
• Blurred vision
• Alarm
• Disorders of the heart
• Liver disorders

The listed side effects are not observed in all patients who are prescribed ondansetron. The most common side effects are highlighted in bold, but others are not excluded. Report all possible side effects to your doctor or pharmacist.

Be sure to discuss these and other recommendations with your doctor or pharmacist.

Taking ondansetron at home:

• Non-absorbable tablets should be swallowed whole. Do not crush or chew before taking.
• Resorbable tablets or films hold on the tongue until completely dissolved. They should not be chewed or swallowed with water or other liquid. Hands must be dry when handling the preparation.
• When taking ondansetron in liquid form, measure the dosage using the measuring device included in the kit.
• Take your dose as soon as possible if you miss it. Do not do this only if there is little time left until the next appointment. In no case do not double the dose at the next dose!
• Store at room temperature. Ondansetron for intravenous administration should be stored in the refrigerator.