Consumer medicine information

Ondansetron-AFT Injection

Ondansetron

BRAND INFORMATION

Brand name

Ondansetron-AFT

Active ingredient

Ondansetron

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Ondansetron-AFT Injection.

SUMMARY CMI

Ondansetron-AFT

Consumer Medicine Information (CMI) summary

The full CMI on the next page has more details. If you are worried about using this medicine, speak to your doctor or pharmacist.

1. Why am I using Ondansetron-AFT?

Ondansetron-AFT contains the active ingredient ondansetron. Ondansetron-AFT is used to help stop nausea (feeling sick) and vomiting which can occur after medical treatments and operations.

For more information, see Section 1. Why am I using Ondansetron-AFT? in the full CMI.

2. What should I know before I use Ondansetron-AFT?

Do not use if you have ever had an allergic reaction to Ondansetron-AFT or any of the ingredients listed at the end of the CMI.

Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.

For more information, see Section 2. What should I know before I use Ondansetron-AFT? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with Ondansetron-AFT and affect how it works.

A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How is Ondansetron-AFT given?

  • Your doctor will decide how much Ondansetron-AFT you should receive and for how long you should receive it.

More instructions can be found in Section 4. How is Ondansetron-AFT given? in the full CMI.

5. What should I know while receiving Ondansetron-AFT?

Things you should do
  • Remind any doctor, dentist or pharmacist you visit that you are receiving Ondansetron-AFT.
  • Keep all of your doctor's appointments, so that your progress can be checked.
Things you should not do
  • Do not take any other medicines whether they require a prescription or not without first telling your doctor.
Driving or using machines
  • Be careful before you drive or use any machines or tools until you know how Ondansetron-AFT affects you.
  • Ondansetron-AFT may cause dizziness or drowsiness in some people.
Looking after your medicine
  • Ondansetron-AFT is stored by hospital staff in the pharmacy or in the ward.
  • This medicine is kept below 30°C and protected from light.

For more information, see Section 5. What should I know while receiving Ondansetron-AFT? in the full CMI.

6. Are there any side effects?

Less serious side effects: related to nervous system (headache), gastrointestinal (constipation, dry mouth, mild stomach cramps, diarrhoea), respiratory (hiccups), eye (prolonged upward deviation of the eyes), injection site (pain, itching, swelling, redness around the site of injection) and other (sensation of warmth or flushing). Speak to your doctor if you have any of these less serious effects and they worry you.

Serious side effects: related to heart (chest pain, tightness in chest, changes in your heart beat, severe dizziness/fainting), blood vessel (low blood pressure), nervous system (seizures), serotonin syndrome (confusion, fever, sweating, fast heart beat, agitation/confusion, involuntary or loss of muscle coordination or shaking, possible loss of consciousness), skin (severe skin reaction where the top layer of the skin detaches from the lower layers), allergic reaction (swelling of eyelids/face/lips/mouth/throat, wheezing or difficulty in swallowing/breathing, skin rash/lumps/hives) and other (blurred vision). Call your doctor straight away, or go straight to the Emergency Department at your nearest hospital if you notice any of these serious side effects.

For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.



FULL CMI

Ondansetron-AFT

Active ingredient: ondansetron (as hydrochloride dihydrate)

Consumer Medicine Information (CMI)

This leaflet provides important information about using Ondansetron-AFT. You should also speak to your doctor or pharmacist if you would like further information or if you have any concerns or questions about using Ondansetron-AFT.

Where to find information in this leaflet:

1. Why am I using Ondansetron-AFT?
2. What should I know before I use Ondansetron-AFT?
3. What if I am taking other medicines?
4. How is Ondansetron-AFT given?
5. What should I know while receiving Ondansetron-AFT?
6. Are there any side effects?
7. Product details

1. Why am I using Ondansetron-AFT?

Ondansetron-AFT contains the active ingredient ondansetron. Ondansetron-AFT belongs to a group of medicines called serotonin receptor-3 antagonists.

Ondansetron-AFT is used to help stop nausea (feeling sick) and vomiting which can occur after medical treatments and operations.

Your doctor may have prescribed Ondansetron-AFT for another reason. Ask your doctor if you have any question about why Ondansetron-AFT has been prescribed for you.

Ondansetron-AFT is not addictive.

2. What should I know before I use Ondansetron-AFT?

Warnings

Do not use Ondansetron-AFT if:

  • you are allergic to ondansetron, or any of the ingredients listed at the end of this leaflet.
  • Always check the ingredients to make sure you can use this medicine.
    Symptoms of an allergic reaction may include shortness of breath, wheezing or difficulty breathing, swelling of the face/lips/tongue or other parts of the body, rash, itching or hives on the skin.
  • you are taking apomorphine (a medicine used to treat Parkinson's disease.

Check with your doctor if you:

  • have any other medical conditions
    − a heart condition related to changes in the rhythm or rate of your heart beat
  • take any medicines for any other condition
  • have allergies to any other medicines, foods, dyes or preservatives
  • have had an allergic reaction with other medicines used to prevent nausea and vomiting; you may have an allergic reaction to Ondansetron-AFT as well
  • have or used to have liver problems
  • have severe constipation.

During treatment, you may be at risk of developing certain side effects. It is important you understand these risks and how to monitor for them. See additional information under Section 6. Are there any side effects?

Pregnancy and breastfeeding

Check with your doctor if you are pregnant or intend to become pregnant. Ondansetron-AFT is not recommended for use while you are pregnant.

Talk to your doctor if you are breastfeeding or intend to breastfeed. Ondansetron-AFT is not recommended for use while you are breastfeeding.

Serotonin syndrome

  • Serotonin syndrome occurs when the level of serotonin gets too high.
  • Symptoms may vary from mild (shivering, diarrhoea) to severe (muscle rigidity, fever, seizures). Check with your doctor if you experience these symptoms while on Ondansetron-AFT treatment.

3. What if I am taking other medicines?

Tell your doctor or pharmacist if you are taking any other medicines, including any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines may interfere with Ondansetron-AFT and affect how it works:

  • medicines used to treat conditions of abnormal heart beat
  • certain medicines used to treat Parkinson's disease (apomorphine), since this may cause low blood pressure and loss of consciousness
  • certain type of antidepressant medicines (known as SSRIs and SNRIs), since this may cause serotonin syndrome
  • tramadol, since the pain-relieving effect thereof might be reduced.

Check with your doctor or pharmacist if you are not sure about what medicines, vitamins or supplements you are taking and if these affects Ondansetron-AFT.

4. How is Ondansetron-AFT given?

How much is given

  • Your doctor will decide how much Ondansetron-AFT you will receive and for how long you will receive it; this depends on your condition and other factors such as your weight.

When Ondansetron-AFT is given

  • Ondansetron-AFT will be administered to you before starting with your chemotherapy or radiotherapy or at the start of, or after, your anaesthesia.

How Ondansetron-AFT is given to you

  • Ondansetron-AFT will only be given to you by a doctor or a nurse
  • Ondansetron-AFT will be injected into a muscle (intramuscular), or diluted with a suitable infusion before it is administered to you as a slow single dose injection/infusion into a vein (intravenous ‘drip’).

If you are given too much Ondansetron-AFT

Since Ondansetron-AFT is given to you in hospital by a doctor or a nurse, it is very unlikely that you will be given too large a dose.

However, if you think that you have received too much Ondansetron-AFT and you experience severe side effects, tell your doctor immediately.

Symptoms of an overdose may include the side effects listed below in the ‘Side effects’ section, but are usually of a more severe nature. Ask your doctor or pharmacist if you have any concerns.

5. What should I know while receiving Ondansetron-AFT?

Things you should do

Keep all of your doctor's appointments, so that your progress can be checked.

Call your doctor straight away if you:

  • become pregnant while being given Ondansetron-AFT.

Remind any doctor, dentist or pharmacist you visit that you are receiving Ondansetron-AFT.

Things you should not do

  • Do not take any other medicines whether they require a prescription or not without first telling your doctor.

Driving or using machines

Be careful before you drive or use any machines or tools until you know how Ondansetron-AFT affects you.

Ondansetron-AFT may cause dizziness in some people.

Looking after your medicine

Ondansetron-AFT is stored by hospital staff in the pharmacy or in the ward.

This medicine is kept below 30°C and protected from light.

Getting rid of any unwanted medicine

If you no longer need to use this medicine or it is out of date, hospital staff will take it to the pharmacy for safe disposal.

Do not use this medicine after the expiry date.

6. Are there any side effects?

All medicines can have side effects. If you do experience any side effects, most of them are minor and temporary. However, some side effects may need medical attention.

See the information below and, if you need to, ask your doctor or pharmacist if you have any further questions about side effects.

Less serious side effects

Less serious side effectsWhat to do
Nervous system-related:
  • headache
Gastrointestinal-related:
  • constipation
  • dry mouth
  • mild stomach cramps
  • diarrhoea
Respiratory system-related:
  • hiccups
Eye-related:
  • prolonged involuntary upward deviation of the eyes
Injection site-related:
  • pain, itching, swelling, redness around the site of injection
Other:
  • sensation of warmth or flushing
Speak to your doctor if you have any of these less serious side effects and they worry you.

Serious side effects

Serious side effectsWhat to do
Heart-related:
  • chest pain
  • tightness in chest
  • changes in your heart beat, e.g. beating faster or slower than normal, or if it beats irregularly or if it ‘throbs’
  • severe dizziness or fainting
Blood vessel system-related:
  • low blood pressure
Nervous system-related:
  • seizures
Serotonin syndrome-related:
  • confusion
  • fever
  • sweating
  • fast heart beat
  • agitation or confusion
  • involuntary or loss of muscle coordination or shaking
  • possible loss of consciousness
Skin-related:
  • severe skin reaction where the top layer of the skin detaches from the lower layers
Allergic reaction-related:
  • swelling of the eyelids, face, lips, mouth or throat
  • wheezing, or difficulty in swallowing or breathing
  • skin rash, skin lumps or hives
Other:
  • blurred vision
Call your doctor straight away, or go straight to the Emergency Department at your nearest hospital if you notice any of these serious side effects.

If your nausea (feeling sick) or vomiting does not go away, ask your doctor what to do.

In certain illnesses and treatments where ondansetron has been used, blood vessel blockage has occurred. However, it is important to note that blood vessel blockage has also occurred in these illnesses and treatments when ondansetron injection has NOT been used. Discuss with your doctor if you have any concerns.

Tell your doctor or pharmacist if you notice anything else that may be making you feel unwell.

Other side effects not listed here may occur in some people.

Reporting side effects

After you have received medical advice for any side effects you experience, you can report side effects to the Therapeutic Goods Administration online at www.tga.gov.au/reporting-problems (Australia) or nzphvc.otago.ac.nz/reporting (New Zealand). By reporting side effects, you can help provide more information on the safety of this medicine.

Always make sure you speak to your doctor or pharmacist before you decide to stop taking any of your medicines.

7. Product details

This medicine is only available with a doctor's prescription.

What Ondansetron-AFT contains

Active ingredient
(main ingredient)		Ondansetron (as hydrochloride dihydrate)
Other ingredients
(inactive ingredients)		Citric acid
Sodium citrate
Sodium chloride
Water for injections

Do not take this medicine if you are allergic to any of these ingredients.

What Ondansetron-AFT looks like

Ondansetron-AFT injection ampoule 4 mg/2 mL:
2 mL clear, colourless, aqueous solution is supplied in clear 2 mL glass ampoules.
Pack size: 1, 5 or 10 ampoules per carton.
AUST R 300688

Ondansetron-AFT injection ampoule 8 mg/4 mL:
4 mL clear, colourless, aqueous solution is supplied in clear 5 mL glass ampoules.
Pack size: 1, 5 or 10 ampoules per carton.
AUST R 300687

Who distributes Ondansetron-AFT

NEW ZEALAND:

AFT Pharmaceuticals Ltd
Level 1, 129 Hurstmere Road
Takapuna
Auckland, 0622
NEW ZEALAND

Phone: 0800 423 823
Email: [email protected]

AUSTRALIA:

AFT Pharmaceuticals Pty Ltd
113 Wicks Road
North Ryde
NSW 2113
AUSTRALIA

Phone: 1800 AFTPHARM (1800 238 74276)
Email: [email protected]

This leaflet was prepared in March 2022.

Published by MIMS July 2022

BRAND INFORMATION

Brand name

Ondansetron-AFT

Active ingredient

Ondansetron

Schedule

S4

 

1 Name of Medicine

Ondansetron (as hydrochloride dihydrate).

2 Qualitative and Quantitative Composition

Ondansetron (as hydrochloride dihydrate) 4 mg/2 mL or 8 mg/4 mL.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Solution for injection.
Clear, colourless, transparent solution, practically free from visible particles.

4 Clinical Particulars

4.1 Therapeutic Indications

Ondansetron is indicated for the prevention and treatment of nausea and vomiting induced by cytotoxic therapy and radiotherapy. Ondansetron (injection) is also indicated for the prevention and treatment of post-operative nausea and vomiting.

4.2 Dose and Method of Administration

Note that other dosage forms including tablets, syrup, suppositories and wafers can be available from other brands.
The emetogenic potential of cancer treatment varies according to the doses and combinations of chemotherapy and radiotherapy regimens used. The route of administration and dose of Ondansetron-AFT should be flexible in the range of 8-32 mg a day and selected as shown below. The lowest effective dose should be used.

Adults.

Emetogenic chemotherapy and radiotherapy.

For the control of chemotherapy or radiotherapy induced emesis or nausea in adults, a single dose of 8 mg of ondansetron should be administered as a slow intravenous injection in not less than 30 seconds, immediately before treatment.
To protect against delayed emesis after the first 24 hours, ondansetron should be continued orally at a dosage of 8 mg twice daily, or given rectally as a 16 mg suppository once daily, for up to 5 days after a course of treatment.

Highly emetogenic chemotherapy.

A single dose of ondansetron 8 mg by slow intravenous injection in not less than 30 seconds, immediately before chemotherapy has been shown to be effective in many patients. Higher doses may be required in some patients, particularly those on high dose cisplatin, and the doses should be adjusted according to the severity of the emetogenic challenge. If required, additional intravenous doses may be given up to a maximum of 32 mg in 24 hours.
Maximum initial Intravenous doses of 16 mg should be given by slow intravenous infusion over at least 15 minutes, since rapid intravenous administration of ondansetron has been associated with a higher incidence of transient visual disturbances. A single dose greater than 16 mg should not be given (see Section 4.4 Special Warnings and Precautions for Use).
Dexamethasone sodium phosphate as a single intravenous dose of 20 mg may be given prior to the first intravenous dose of ondansetron before chemotherapy, to potentiate the antiemetic effects of ondansetron.
An alternative to intravenous treatment is a single oral dose of up to 24 mg ondansetron taken with oral dexamethasone 12 mg, 1-2 hours before commencing chemotherapy.
Initial treatment may be followed by oral ondansetron 8 mg 12-hourly or rectal ondansetron 16 mg once daily for up to 5 days to protect against delayed emesis.

Post-operative nausea and vomiting (PONV) (injection only).

For prevention of post-operative nausea and vomiting in adults, ondansetron may be administered as a single dose of 4 mg, given by intramuscular or slow intravenous injection at induction of anaesthesia.
For treatment of established post-operative nausea and vomiting, a single dose of 4 mg given by intramuscular or slow intravenous injection is recommended in most patients. If necessary, the dose may be increased to 8 mg.

Children.

Emetogenic chemotherapy and radiotherapy (injection).

Experience is currently limited but ondansetron was effective and well tolerated in children over the age of 4 years, when given intravenously at a dose of 5 mg/m2 over 15 minutes, immediately before chemotherapy, followed by oral therapy at doses of 4 mg twice daily for up to 5 days. The dose of 5 mg/m2 is based on limited data. Suppositories are not recommended for use in children.

Post-operative nausea and vomiting (injection only).

For prevention of post-operative nausea and vomiting in children aged 2-12 years having surgery under general anaesthesia, ondansetron may be administered by slow intravenous injection (not less than 30 seconds) at a dose of 0.1 mg/kg up to a maximum of 4 mg either prior to, at or after induction of anaesthesia.
For treatment of established post-operative nausea and vomiting, ondansetron may be administered by slow intravenous injection at a dose of 0.1 mg/kg up to a maximum of 4 mg.

PONV in children and adolescents (aged 1 month to 17 years) (oral formulations).

No studies have been conducted on the use of orally administered ondansetron in the prevention or treatment of post-operative nausea and vomiting; slow IV injection (not less than 30 seconds) is recommended for this purpose.
Repeat dosing has not been studied in paediatric patients who experience nausea and/or vomiting despite receiving ondansetron prophylaxis or who continue to experience symptoms after ondansetron treatment.

Elderly patients.

Emetogenic chemotherapy and radiotherapy (injection). Efficacy and tolerance in patients aged over 65 years was similar to that seen in younger adults indicating no need to alter dosage or route of administration in the elderly.
CINV and RINV in elderly patients. Ondansetron is well tolerated by patients over 65 years of age.
IV formulation.

Elderly patients aged 75 years or older.

A single dose of intravenous ondansetron given for the prevention of chemotherapy-induced nausea and vomiting (CINV) must not exceed 8 mg (infused over at least 15 minutes).

Adult patients aged less than 75 years.

A single dose of intravenous ondansetron given for the prevention of CINV in adults (aged less than 75 years) must not exceed 16 mg (infused over at least 15 minutes).
Ondansetron causes a dose-dependent prolongation of the electrocardiographic-corrected QT interval (QTc), which can lead to Torsade de Pointes-a potentially life-threatening heart arrhythmia. Therefore, the above new dose restrictions are in place for use of intravenous ondansetron.
Post-operative nausea and vomiting (injection only). There is limited experience in the use of ondansetron in the prevention and treatment of post-operative nausea and vomiting in the elderly.

Patients with renal impairment.

No alteration of daily dosage or frequency of dosing, or route of administration are required.

Patients with hepatic impairment.

A study which investigated the effect of hepatic impairment on the pharmacokinetics of ondansetron in 24 subjects showed that the plasma clearance of ondansetron is reduced to about 20% of normal, and the serum half-life is significantly prolonged in subjects with severe impairment of hepatic function.
The results in patients with only mildly or moderately impaired hepatic function were less clear. The study showed that in this group the plasma clearance of ondansetron fell to about 50% of that seen in healthy volunteers. Subjects with mild and moderate impairment were not distinguishable from each other for any parameter. This was believed to be partly due to the lack of sensitivity of the Pugh classification system in distinguishing between patients with mild or moderate impairment.
It is recommended that a total daily dose of 8 mg should not be exceeded for patients with moderate or severe hepatic dysfunction. For optimum clinical effect it is recommended that this total daily dose be administered before chemotherapy or radiotherapy.
The severity of the liver disease was assessed according to Pugh's modification of Child's classification (Pugh et al, Brit J. Surg. 1973, 60 (8), 646-649). Patients with a Pugh score of 5 or less were considered to have good hepatic function. A patient with a score of 6 was graded as having mild hepatic impairment, 7 to 9 as moderate hepatic impairment and 10 or more as severe hepatic impairment. The clinical features used in the grading and the weighting system applied are shown in Table 1.

Patients with poor sparteine/debrisoquine metabolism.

There were no significant differences among poor and extensive debrisoquine categorised metabolisers with regard to ondansetron disposition (area under the curve, total systemic clearance, elimination half-life) following a single 8 mg intravenous dose. The effect of repeated dosing was not investigated, nevertheless dosage adjustments will probably not be required in patients receiving ondansetron by either the oral or intravenous route.

Compatibility with other drugs.

Administration recommendations.

Slow intravenous injection from an infusion bag or syringe pump. The following drugs may be administered via the Y-site of the ondansetron giving set for ondansetron concentrations of 16-160 micrograms/mL (i.e. 8 mg/500 mL and 8 mg/50 mL respectively).

Cisplatin.

Concentrations up to 0.48 mg/mL (i.e. 240 mg in 500 mL) administered over one to eight hours.

Fluorouracil.

Concentrations up to 0.8 mg/mL (i.e. 2.4 g in 3 litres or 400 mg in 500 mL) administered at a rate of at least 20 mL per hour (500 mL per 24 hours). Higher concentrations of fluorouracil may cause precipitation of ondansetron. The fluorouracil infusion may contain up to 0.045% w/v magnesium chloride in addition to other excipients shown to be compatible.

Carboplatin.

Concentrations in the range 0.18 mg/mL-9.9 mg/mL (i.e. 90 mg in 500 mL to 990 mg in 100 mL), administered over ten minutes to one hour.

Etoposide.

Concentrations in the range 0.14 mg/mL to 0.25 mg/mL (i.e. 72 mg in 500 mL to 250 mg in 1 litre), administered over thirty minutes to one hour.

Ceftazidime.

Doses in the range 250-2,000 mg reconstituted with Water for Injections BP as recommended by the manufacturer (i.e. 2.5 mL for 250 mg and 10 mL for 2 g ceftazidime) and given as an intravenous bolus injection over approximately five minutes.

Cyclophosphamide.

Doses in the range 100 mg to 1 g, reconstituted with Water for Injections BP, 5 mL per 100 mg cyclophosphamide, as recommended by the manufacturer, and given as an intravenous bolus injection over approximately five minutes.

Doxorubicin.

Doses in the range 10-100 mg reconstituted with Water for Injections BP, 5 mL per 10 mg doxorubicin, as recommended by the manufacturer and given as an intravenous bolus injection over approximately five minutes.

Dexamethasone.

Dexamethasone sodium phosphate 20 mg may be administered as a slow intravenous injection over 2-5 minutes. The intravenous administration of dexamethasone should be physically separated from ondansetron either by administration via a different line or by flushing the line with 0.9% Sodium Chloride injection in between the two drugs.

4.3 Contraindications

Based on reports of profound hypotension and loss of consciousness when ondansetron was administered with apomorphine hydrochloride, concomitant use with apomorphine is contraindicated.
Hypersensitivity to any component of the preparation (see Section 4.4 Special Warnings and Precautions for Use).

4.4 Special Warnings and Precautions for Use

Hypersensitivity reactions have been reported in patients who have exhibited hypersensitivity to other selective 5HT3 receptor antagonists.
Ondansetron prolongs the QT interval in a dose-dependent manner. In addition, post-marketing cases of Torsade de Pointes have been reported in patients using ondansetron. Avoid ondansetron in patients with congenital long QT syndrome. Ondansetron should be administered with caution to patients who have or may develop prolongation of QTc, including patients with electrolyte abnormalities, congestive heart failure, bradyarrhythmia or patients taking other medicinal products that lead to QT prolongation or electrolyte abnormalities.
Hypokalemia and hypomagnesemia should be corrected prior to ondansetron administration.
Serotonin syndrome has been described following the concomitant use of ondansetron and other serotonergic drugs (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions). If concomitant treatment with ondansetron and other serotonergic drugs is clinically warranted, appropriate observation of the patient is advised.
As ondansetron is known to increase large bowel transit time, patients with signs of subacute intestinal obstruction should be monitored following administration.
Repeat dosing has not been studied in paediatric patients who experience nausea and/or vomiting despite receiving ondansetron prophylaxis or who continue to experience symptoms after ondansetron treatment.

Use in the elderly.

No data available.

Paediatric use.

No data available.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

There is no evidence that ondansetron either induces or inhibits the metabolism of other drugs commonly coadministered with it. Specific studies have shown that there are no pharmacokinetic interactions when ondansetron is administered with alcohol, temazepam, alfentanil, furosemide, tramadol or propofol.
Ondansetron is metabolised by multiple hepatic cytochrome P450 enzymes: CYP3A4, CYP2D6 and CYP1A2. Due to the multiplicity of metabolic enzymes capable of metabolising ondansetron, enzyme inhibition or reduced activity of one enzyme (e.g. CYP2D6 genetic deficiency) is normally compensated by other enzymes and should result in little or no significant change in overall ondansetron clearance or dose requirement.
Caution should be exercised when ondansetron is coadministered with drugs that prolong the QT interval and/or cause electrolyte abnormalities (see Section 4.4 Special Warnings and Precautions for Use).
Based on reports of profound hypotension and loss of consciousness when ondansetron was administered with apomorphine hydrochloride, concomitant use with apomorphine is contraindicated.
In patients treated with potent inducers of CYP3A4 (i.e. phenytoin, carbamazepine, and rifampicin), the oral clearance of ondansetron was increased and ondansetron blood concentrations were decreased.
Following a single 8 mg tablet dose of ondansetron, a threefold to fourfold decrease in the systemic exposure has been seen in adult epileptic subjects maintained on chronic doses of carbamazepine (n=8) or phenytoin (n=8) and not receiving chemotherapy. The effect of these enzyme inducing agents on intravenous ondansetron has not been assessed, but the absence of any first pass effects would be expected to result in a smaller change in exposure than seen following oral dosing. Due to the limited efficacy data in subjects on antiepileptics and the many variables that may influence exposure and response, the clinical significance of this drug interaction in cancer patients receiving chemotherapy is not known.

Serotonergic drugs (e.g. SSRIs and SNRIs).

Serotonin syndrome (including altered mental status, autonomic instability and neuromuscular abnormalities) has been described following the concomitant use of ondansetron and other serotonergic drugs, including selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenaline reuptake inhibitors (SNRIs) (see Section 4.4 Special Warnings and Precautions for Use).
Data from small studies indicate that ondansetron may reduce the analgesic effect of tramadol.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

Oral doses of ondansetron up to 15 mg/kg/day in rats had no effect on male or female fertility.
(Category B1)
The safety of ondansetron for use in human pregnancy has not been established. Evaluation of experimental animal studies does not indicate direct or indirect harmful effects with respect to the development of the embryo, or foetus, the course of gestation and peri- and post-natal development. However as animal studies are not always predictive of human response the use of ondansetron in pregnancy is not recommended.
 Tests have shown that ondansetron is excreted in the breast milk of rats. It is therefore recommended that mothers receiving ondansetron should not breast-feed their babies.

4.7 Effects on Ability to Drive and Use Machines

The effects of this medicine on a person's ability to drive and use machines were not assessed as part of its registration.

4.8 Adverse Effects (Undesirable Effects)

Adverse events are listed below by system organ class and frequency. Frequencies are defined as: very common (≥ 1/10), common (≥ 1/100 and < 1/10), uncommon (≥ 1/1000 and < 1/100), rare (≥ 1/10,000 and < 1/1000) and very rare (< 1/10,000), including isolated reports. Very common, common and uncommon events were generally determined from clinical trial data. The incidence in placebo was taken into account. Rare and very rare events were generally determined from postmarketing spontaneous data.
The following frequencies are estimated at the standard recommended doses of ondansetron according to indication and formulation. The adverse event profiles in children and adolescents were comparable to that seen in adults.

Immune system disorders.

Rare: immediate hypersensitivity reactions, sometimes severe, including anaphylaxis.

Nervous system disorders.

Very common: headache.
Uncommon: seizures, movement disorders (including extrapyramidal reactions such as oculogyric crisis, dystonic reactions and dyskinesia have been observed without definitive evidence of persistent clinical sequelae).
Rare: dizziness during rapid IV administration.

Eye disorders.

Rare: transient visual disturbances (e.g. blurred vision) predominantly during IV administration.
Very rare: transient blindness predominantly during IV administration.
The majority of the blindness cases reported resolved within 20 minutes. Most patients had received chemotherapeutic agents, which included cisplatin. Some cases of transient blindness were reported as cortical in origin.

Cardiac disorders.

Uncommon: arrhythmias, chest pain with or without ST segment depression, bradycardia.
Rare: QTc prolongation (including Torsade de Pointes).

Vascular disorders.

Common: sensation of warmth or flushing.
Uncommon: hypotension.

Respiratory, thoracic and mediastinal disorders.

Uncommon: hiccups.

Gastrointestinal disorders.

Common: constipation, xerostomia, local anal/rectal burning sensation following insertion of suppositories.

Hepatobiliary disorders.

Uncommon: asymptomatic increases in liver function tests.
These events were observed commonly in patients receiving chemotherapy with cisplatin.

Skin and subcutaneous tissue disorders.

Very rare: toxic skin eruption, including toxic epidermal necrolysis.

General disorders and administration site conditions.

Common: local IV injection site reactions.
To date there has been limited safety experience in controlled trials following intramuscular administration.
Of 7,400 patients who have received intravenous ondansetron during clinical trials, 11 experienced major cardiovascular events, including 3 fatalities, which were considered to be drug-related by the investigators (1 probable, 10 possible). It is well known that cardiovascular events, especially of a vascular occlusive nature are not uncommon among patients with cancer, and these events are further increased with cytotoxic chemotherapy, particularly cisplatin.
Table 2 shows adverse events occurring in ≥ 1% of paediatric patients (either group) in three pivotal clinical trials for prevention of post-operative nausea and vomiting. Ondansetron appears to be as well tolerated as placebo.
The overall incidence of adverse events was similar for ondansetron (53%) and placebo (56%). The most commonly reported adverse events were eye disorder(s) as a result of ophthalmic operations, wound problems at the surgical site, nausea and/or vomiting, drowsiness/sedation, anxiety/agitation and headache. These events are not unexpected in patients undergoing surgery and there was little difference of these between treatment groups. However, the incidence of nausea and/or vomiting reported as an adverse event was significantly higher in patients who had received placebo (11%) compared to those who had received ondansetron (6%). See Table 3.
Fewer adverse events were reported with ondansetron (36%) than with placebo (47%). The most common adverse events were similar to those reported in clinical trials for the prevention of post-operative nausea and vomiting.
Occasionally local reactions at the site of intravenous injection have been reported. See Table 4.
The overall incidence rate was 45% in the placebo group and 47% in the IV ondansetron group.
The neurological body system was associated with the highest incidence of adverse events (placebo approximately 23%; ondansetron 24%). These events were predominantly headache, dizziness and drowsiness.
Cardiovascular adverse events (bradycardia and hypotension) occurred in approximately 4% in both placebo and ondansetron groups; gastrointestinal adverse events (constipation, nausea/vomiting, flatulence and abdominal pain) occurred in approximately 7% of patients both receiving placebo and IV ondansetron.
The incidence rates were generally similar in both treatment groups for all body systems.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems or https://nzphvc.otago.ac.nz/reporting/ (New Zealand).

4.9 Overdose

Little is at present known about overdosage with ondansetron, however, a limited number of patients received overdoses. Manifestations that have been reported include visual disturbances, severe constipation, hypotension and a vasovagal episode with transient second-degree AV block. In all instances, the events resolved completely. There is no specific antidote for ondansetron, therefore in cases of suspected overdose, symptomatic and supportive therapy should be given as appropriate.
Ondansetron prolongs QT interval in a dose-dependent fashion. ECG monitoring is recommended in cases of overdose.
Cases consistent with serotonin syndrome have been reported in young children following oral overdose.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia) or the National Poisons Centre on 0800 POISON (0800 764766) (New Zealand).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Ondansetron is a potent, highly selective 5HT3 receptor-antagonist. Its precise mode of action in the control of nausea and vomiting is not known. Chemotherapeutic agents and radiotherapy may cause release of 5HT in the small intestine initiating a vomiting reflex by activating vagal afferents via 5HT3 receptors. Ondansetron blocks the initiation of this reflex. Activation of vagal afferents may also cause a release of 5HT in the area postrema, located on the floor of the fourth ventricle, and this may also promote emesis through a central mechanism. Thus, the effect of ondansetron in the management of the nausea and vomiting induced by cytotoxic chemotherapy and radiotherapy is due to antagonism of 5HT3 receptors on neurones located both in the peripheral and central nervous system. The mechanisms of action in post-operative nausea and vomiting are not known but there may be common pathways with cytotoxic induced nausea and vomiting. In psychomotor testing ondansetron does not impair performance nor cause sedation. Ondansetron does not alter plasma prolactin concentrations.
A study in cloned human cardiac ion channels has shown ondansetron has the potential to affect cardiac repolarisation via blockade of HERG potassium channels. The clinical relevance of this finding is uncertain.

Clinical trials. Chemotherapy and radiotherapy induced nausea and vomiting (CINV and RINV).

Adult studies.

Highly emetogenic chemotherapy.

In a double-blind, randomised study 152 patients were given ondansetron 8 mg IV single dose and 173 patients were given 32 mg IV single dose 30 minutes prior to cisplatin (> 50 mg/m2). No significant difference in terms of emesis control or grade of nausea was demonstrated between 8 mg or 32 mg. However, in some studies conducted in patients receiving medium (50-90 mg/m2) or high doses (> 100 mg/m2) of cisplatin chemotherapy, the 32 mg single dose has demonstrated a statistically significant superiority over the 8 mg single dose with regard to control of emesis (see Section 4.2 Dose and Method of Administration).
In a double-blind, randomised, cross-over trial, 103 chemotherapy naive patients scheduled to receive cisplatin (50-120 mg/m2) chemotherapy were recruited. Ninety-one patients completed both courses of ondansetron 0.15 mg/kg (8 mg) IV x 3 with or without dexamethasone 20 mg IV. The combination of ondansetron and dexamethasone was shown to be significantly superior to ondansetron alone.
In a randomised, double-blind parallel group study, 420 patients were randomised to receive either ondansetron 16 mg suppository prior to cisplatin chemotherapy (≥ 50 mg/m2) on day 1 followed by ondansetron 16 mg suppository once daily for a further 2 days, or ondansetron 8 mg IV prior to cisplatin chemotherapy followed by ondansetron 8 mg orally twice daily for a further 2 days. Results from the primary efficacy analysis (i.e. ≤ 2 emetic episodes on day 1) show that the ondansetron suppository and ondansetron IV and oral combined regimens are equivalent. However, results from the secondary efficacy analyses (e.g. number of emetic episodes on Day 1, the worst day of Days 1-3 and overall of Days 1-3) showed that the ondansetron suppository was less effective. Patients on ondansetron IV and oral combined regimen remained free of emesis for significantly longer than patients receiving ondansetron suppository.
In a randomised, double-blind, parallel group study 542 patients were randomised to receive either ondansetron tablets (3 x 8 mg) plus dexamethasone capsules (2 x 6 mg), or IV ondansetron 8 mg plus IV dexamethasone 20 mg, prior to cisplatin infusion. 24 mg of ondansetron administered orally was as effective as ondansetron 8 mg given IV in controlling acute emesis and nausea induced by cisplatin chemotherapy.

Emetogenic chemotherapy.

In a double-blind, parallel group study 82 patients were randomised to either ondansetron 8 mg IV prior to cyclophosphamide (> 500 mg/m2) based chemotherapy (doxorubicin or epirubicin > 40 mg/m2) followed by 8 mg orally three times a day for 3-5 days or metoclopramide 60 mg IV prior to chemotherapy followed by 20 mg orally three times a day for 3-5 days. Ondansetron was shown to be significantly superior to metoclopramide.
In a randomised, single-blind study, ondansetron 8 mg orally twice daily in 155 patients was compared with ondansetron 8 mg orally three times daily in 153 patients for 3-5 days following chemotherapy. Ondansetron 8 mg IV was given prior to cyclophosphamide (> 500 mg/m2) based chemotherapy (doxorubicin or epirubicin > 40 mg/m2) on Day 1. Ondansetron 8 mg given orally twice daily was as effective as ondansetron 8 mg given orally three times daily.
Paediatric studies. Three open-label, uncontrolled, non-comparative studies have been performed with 182 patients, aged 4-18 years old with cancer who were given a variety of cisplatin or non-cisplatin regimens. In these trials an initial IV dose of ondansetron was followed by oral administration of ondansetron. In these studies, 58% of the 170 evaluable patients had 0 emetic episodes on Day 1.

Post-operative nausea and vomiting (PONV).

Prevention of PONV.

Adult studies*.

Surgical patients received ondansetron immediately before the induction of general balanced anaesthesia. In a double-blind, placebo-controlled study 136 patients given ondansetron 4 mg IV immediately prior to general anaesthesia was significantly more effective than placebo.
*The majority of patients included in the prevention of PONV studies using ondansetron have been adult women receiving balanced anaesthesia for gynaecological surgery.

Paediatric studies.

Three, large, double-blind, placebo-controlled studies have been performed in 1,049 male and female patients (2-12 years of age) undergoing general anaesthesia with nitrous oxide. The surgical procedures included tonsillectomy with or without adenoidectomy, strabismus surgery, herniorrhaphy, and orchidopexy. Patients were randomised to either single IV doses of ondansetron (0.1 mg/kg for children weighing 40 kg or less, a single 4 mg dose for children weighing more than 40 kg) or placebo. Study drug was administered over at least 30 seconds, immediately prior to or following anaesthesia induction. Ondansetron showed significant statistical superiority over placebo in preventing post-operative nausea and vomiting. Repeat dosing was not undertaken in these studies. Children at greater risk of post-operative nausea and vomiting are more likely to benefit from prophylaxis; this includes children with a history of motion sickness or previous post-operative nausea and vomiting. No comparisons with other drugs for the prevention of nausea and/or vomiting are available.
Treatment of PONV.

Adults*.

Two hundred and twenty-one adult surgical patients receiving general balanced anaesthesia, who received no prophylactic anti-emetics and who experienced nausea and/or vomiting within 2 hours post-operatively were evaluated in a double-blind study. Patients who experienced an episode of post-operative nausea and/or vomiting were given ondansetron 4 mg IV over 2-5 minutes, and this was significantly more effective than placebo.
*The majority of patients treated for PONV in studies using ondansetron have been adult women receiving balanced anaesthesia for gynaecological surgery.

Paediatric study.

One, large, double-blind, placebo-controlled study was performed in 351 male and female outpatients (2-12 years of age) who received general anaesthesia with nitrous oxide and no prophylactic anti-emetics. Surgical procedures were restricted. Patients who experienced two or more emetic episodes within 2 hours following discontinuation of nitrous oxide were randomised to a single IV dose of (0.1 mg/kg for children weighing 40 kg or less, a single 4 mg dose for children weighing more than 40 kg) or placebo administered over at least 30 seconds. Ondansetron demonstrated statistically significant superiority over placebo in preventing further episodes of nausea and vomiting. Repeat dosing was not a feature of this study. No data, involving comparisons with active treatments, have been evaluated.

5.2 Pharmacokinetic Properties

Absorption.

Extent of absorption following intramuscular injection into a lateral compartment of the thigh is identical to intravenous injection and absorption is rapid with Tmax occurring approximately 10 minutes after administration. The Cmax after intramuscular administration is 61% lower than that following intravenous administration.

Distribution.

The plasma protein binding is 70-76%. The volume of distribution is 1.8 L/kg.
In a study of 21 children aged 3-12 years receiving elective surgery with general anaesthesia, the clearance and volume of distribution of ondansetron following a single intravenous dose of 2 mg (3-7 years old) or 4 mg (8-12 years old) were reduced. The size of the change was age-related with clearance falling from about 300 mL/min at 12 years of age to 100 mL/min at 3 years. Volume of distribution fell from about 75 L at 12 years to 17 L at 3 years.

Metabolism.

In patients with severe hepatic impairment, systemic clearance is markedly reduced with prolonged elimination half-lives (15-32 h) and an oral bioavailability approaching 100% because of reduced presystemic metabolism. Ondansetron is extensively metabolised in humans, with approximately 5% of a radiolabelled dose recovered as the parent compound from the urine.
The primary metabolic pathway is hydroxylation on the indole ring followed by glucuronide or sulphate conjugation. Although some nonconjugated metabolites have pharmaceutical activity, these are not found in plasma concentrations likely to significantly contribute to the biological activity of ondansetron.
The clinical safety of ondansetron in children under 2 years has not been established. Increased incidence of mortality with no specific target organ toxicity has been observed in young rats with immature drug metabolising enzymes.

Excretion.

Ondansetron is a substrate for multiple human hepatic cytochrome P450 enzymes including CYP1A2, CYP2D6 and CYP3A4. This multiplicity of metabolic enzymes capable of metabolising ondansetron means that inhibition or loss of one enzyme (e.g. CYP2D6 genetic deficiency) results in little change in overall rates of ondansetron elimination.

5.3 Preclinical Safety Data

Genotoxicity.

Ondansetron did not induce mutations in Salmonella typhimurium, Escherichia coli or Chinese Hamster Ovary cells in the presence or absence of metabolic activation, and showed no potential for causing chromosomal damage in vitro in peripheral human lymphocytes or in vivo in a mouse micronucleus assay. No evidence for DNA damage was observed with ondansetron in a yeast mitotic gene conversion assay.

Carcinogenicity.

No evidence for carcinogenic activity was found in two-year studies at ondansetron doses up to 10 mg/kg/day by gavage in rats or up to 30 mg/kg/day via drinking water in mice.

6 Pharmaceutical Particulars

6.1 List of Excipients

Citric acid, sodium citrate, sodium chloride, nitrogen as well as water for injections.

6.2 Incompatibilities

Ondansetron injection should not be administered in the same syringe or infusion as any other medication.
Ondansetron injection is for single use in one patient on one occasion only, discard any residue.
Ondansetron injection contains no antimicrobial agent.
Ondansetron injection ampoules should not be autoclaved.

Compatibility with intravenous fluids.

Ondansetron injection should only be admixed with those infusion solutions which re recommended.
Ondansetron injection can be stored at or below 25°C for not more than 6 hours or at 2-8°C for not more than 24 hours after mixing with one of the following intravenous infusion fluids: Sodium Chloride Intravenous Infusion BP 0.9% w/v; Glucose Intravenous Infusion BP 5% w/v; Mannitol Intravenous Infusion BP 10% w/v; Ringer's Intravenous Infusion; Potassium Chloride 0.3% w/v and Sodium Chloride 0.9% w/v Intravenous Infusion BP; Potassium Chloride 0.3% w/v and Glucose 5% w/v Intravenous Infusion BP.
Compatibility studies have been undertaken in polyvinyl chloride infusion bags and polyvinyl chloride administration sets. It is considered that adequate stability would also be conferred by the use of polyethylene infusion bags or type 1 glass bottles. Dilutions of ondansetron in sodium chloride 0.9% w/v or in glucose 5% w/v have been demonstrated to be stable in polypropylene syringes. It is considered that ondansetron injection diluted with other compatible infusion fluids would be stable in polypropylene syringes.

Warning.

Diluted solutions which are hazy, discoloured or contain visible particulate matter must be discarded.

6.3 Shelf Life

24 months.

6.4 Special Precautions for Storage

Store below 30°C. Do not freeze.
Ondansetron injection should be protected from light.
To reduce microbiological contamination hazards, the diluted solutions should be prepared immediately prior to use and infusion commenced as soon as practicable after preparation of the mixture. If storage is necessary, keep at or below 25°C for not more than 6 hours or at 2-8°C for not more than 24 hours.

6.5 Nature and Contents of Container

Type 1 clear glass ampoule.

Ondansetron-AFT injection ampoule 4 mg/2 mL.

Ampoules each containing 4 mg ondansetron (as hydrochloride dihydrate) in 2 mL aqueous solution for intramuscular or intravenous administration in packs of one, five and ten.

Ondansetron-AFT injection ampoule 8 mg/4 mL.

Ampoules each containing 8 mg ondansetron (as hydrochloride dihydrate) in 4 mL aqueous solution for intravenous administration in packs of one, five and ten.
Not all strengths, dose forms, pack sizes and container types are being distributed in Australia and New Zealand.

6.6 Special Precautions for Disposal

Any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Chemical structure.


CAS number.

103639-04-9 (ondansetron hydrochloride dihydrate); 99614-02-5 (ondansetron).
The chemical name of ondansetron hydrochloride dihydrate is (3RS)-9-Methyl-3-[(2-methyl-1H-imidazol-1-yl) methyl]-1,2,3,9-tetrahydro-4H-carbazol-4-one hydrochloride dihydrate. The molecular formula of ondansetron hydrochloride dihydrate is C18H19N3O.HCl.2H2O and the relative molecular mass is 365.9. It takes the form of a white to off-white powder with a melting point of 177°C. It is sparingly soluble in water and in alcohol, soluble in methanol and slightly soluble in methylene chloride. It is soluble in saline (0.9% w/v) to about 8 mg/mL. The pKa of ondansetron hydrochloride dihydrate as determined by a solubility procedure is 7.4. The distribution coefficient between n-octanol and water is pH dependent with log D = 2.2 at a pH of 10.6 and log D = 0.6 at a pH of 5.95. The molecular formula for ondansetron is C18H19N3O and its molecular mass is 293.4.

7 Medicine Schedule (Poisons Standard)

S4 - Prescription Only Medicine.

Summary Table of Changes