Consumer medicine information

What is in this leaflet

This leaflet answers some common questions about Nitronox. It does not contain all the available information.

It does not take the place of talking to your doctor, anaesthetist, surgeon or dentist.

All medicines have risks and benefits. Your doctor or dentist has weighed the risks of you using Nitronox against the benefits they expect it will have for you.

If you have any concerns about using Nitronox, ask your doctor or dentist.

Keep this leaflet with you, you may want to read it again.

What Nitronox is used for

Nitronox is a gas mixture of 50% Medical Nitrous Oxide and 50% Medical Oxygen used for general anaesthesia.

Nitronox works by relieving pain for certain procedures.

Your doctor may prescribe Nitronox for another purpose. Ask your doctor if you have any questions about why Nitronox has been prescribed for you.

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

Before you use Nitronox

When you must not use it

Do not use Nitronox if:

1. You have an allergy to nitrous oxide or any other component in the gas or have had an allergic reaction in the past.
2. You have a condition where air is entrapped within your body and it might expand when given Nitronox (eg bowel obstruction, blocked middle ear, following a recent dive). Ask your doctor for full details of these conditions.
3. You have been using it for a prolonged period without proper monitoring of your blood.
4. You are intoxicated or heavily sedated
5. You have recently had any surgery on our eyes or ears where injections of gas have been used.

Do not use Nitronox if the cylinder is damaged or shows signs of tampering or it has degraded.

Before you start to use it

You must tell your doctor or dentist if:

1. You are allergic to any other medicines, foods, dyes or preservatives.
2. You have had a reaction to nitrous oxide or any other general anaesthetic or pain relief medication in the past.
3. You have had a general anaesthetic or surgery in the past.
4. You have or have had any other health problems or medical conditions, including:

• A condition known as malignant hyperthermia or a family history of it.
• Low blood pressure
• Low vitamin B12 levels
• Problems with addiction to medicines
• Bone marrow problems including various cells in the blood
• Neurological diseases
• Conditions in which air is entrapped within the body

5. You are pregnant or intend to become pregnant.

Your doctor or dentist will discuss the risks and benefits of using Nitronox when pregnant.

6. You are breastfeeding or wish to breastfeed.

Your doctor or dentist will discuss the risks and benefits of using Nitronox when breastfeeding.

7. Care should be taken when using Nitronox as it is stored under high pressure in gas cylinders. Contact with eyes or skin may result in cold burns.

There are also safe working exposure levels and important storage instructions. Please discuss these with your doctor if you have any questions.

8. You have had long term usage or been chronically exposed to Nitronox.

Taking other medicines

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

Some commonly used medicines that may interfere with Nitronox include:

• Pain relievers
• Anaesthetics
• Methotrexate
• Medicines which may affect your nervous system
• Medicines which may interfere with Vitamin B12 and/or folate metabolism

These medicines may be affected by Nitronox or may affect how well it works. You may need to take different amounts of your medicine or you may need to take different medicines.

Some medicines may affect the way others work. Ask what to do when using Nitronox with other medicines.

Your doctor may have more information on medicines to avoid while using Nitronox.

If you have not told your doctor about any of the above, tell them before you start using Nitronox.

How to use Nitronox

Nitronox should only be used under the supervision of your doctor or dentist.

How much to use and how to use it

The amount of Nitronox given to you will be decided by your doctor or dentist. It is usually given to you by breathing it through a mask.

Follow all directions given to you by your doctor or dentist carefully.

These directions may differ from the information contained in this leaflet.

If you do not understand the instructions, ask your doctor for help.

How long to use it

Your doctor will decide for how long you need to use Nitronox.

If you use too much (overdose)

As Nitronox is most likely to be given to you in hospital under the direction of your doctor, it is very unlikely you will receive an overdose.

However, if this happened, quick action can be taken to maintain your breathing.

If you have any questions then ask your doctor.

After you have used Nitronox

Things you must not do

Following analgesia:
Ask your doctor or dentist when it is safe for you to drive, operate machinery or perform activities following the use of Nitronox.

Side effects

Tell your doctor or dentist as soon as possible if you do not feel well while you are using Nitronox.

Nitronox may have unwanted side effects in some people. All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side effects.

Ask your doctor any questions you may have.

Rare cases of respiratory depression in newborns have been observed, when using nitrous oxide close to delivery, newborns should be supervised for possible side effects.

Tell your doctor or dentist if you notice any of the following and they worry you:

• Nausea, vomiting
• Headache, dizziness, drowsiness

These side effects are usually mild.

Tell your doctor or dentist immediately if you notice any of the following:

• Confusion, excitation and depression of the central nervous system
• Breathing problems
• Anxiety, agitation, disorientation, hallucination
• Heart problems
• Pins and needles, changes in sensation
• Blood disorders
• Seizures
• Abdominal pain, bloating
• Addiction
• impaired vision
• Ear pain
• Vitamin B12 deficiency

These are serious side effects.

You may need urgent medical attention. Serious side effects are rare. Other side effects may occur as a result of your operation or other medications and anaesthetics received so check with your doctor or dentist if you have any concerns.

If any of the above occur, tell your doctor or dentist immediately or go to casualty at your nearest hospital.

Other side effects not listed above may also occur in some patients.

Tell your doctor or dentist if you notice anything else that is making you feel unwell.

Ask your doctor or dentist if you don’t understand anything in this list.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

After using Nitronox

Storage

Nitronox is stored at ambient temperature in cylinders by your doctor or hospital under specific instructions.

Disposal

All cylinders are the property of the manufacturer as indicated on the label. All cylinders are returnable to the manufacturer

Product Description

What it looks like

Nitrous oxide is a sweet smelling, colourless, non-irritating gas. Oxygen is a colourless, odourless gas. Nitronox supplied in a cylinder with a white body and a ultramarine shoulder.

Single cylinders are available in Cylinder sizes C (0.5 m³), D (1.7 m³), E (4.3 m³) and G (8.8 m³).

Ingredients

Active Ingredient
Nitrous oxide- 50%
Oxygen – 50%

Sponsor

Air Liquide Healthcare Pty Ltd
Level 4, Suite 4
247 Coward Street
Mascot, NSW 2020

Australian Registration Number

AUST R 32752

This leaflet was prepared on November 2022.

Published by MIMS March 2023

1 Name of Medicine

Nitrous oxide and oxygen.

2 Qualitative and Quantitative Composition

The specifications for each of the main components are presented separately.
Nitrous oxide. Complies with the requirements of the current European Pharmacopoeia monograph for nitrous oxide, N₂O.
Nitrous oxide: 98.0% v/v minimum.
Carbon dioxide: 300 ppm v/v maximum.
Carbon monoxide: 5 ppm v/v maximum.
Oxides of nitrogen (NO/NO₂): 2 ppm v/v maximum.
Water (vapour): 67 ppm v/v maximum.
Oxygen. Complies with the requirements of the current European Pharmacopoeia monograph for oxygen, oxygen, O₂.
Oxygen: 99.5% v/v minimum.
Carbon dioxide: 300 ppm v/v maximum.
Carbon monoxide: 5 ppm v/v maximum.
Water (vapour): 67 ppm v/v maximum.
Nitronox is a homogenous gas mixture of oxygen and nitrous oxide in equal volumetric proportions.
Nitrous oxide is the active ingredient.
Nitrous oxide is a sweet smelling colourless non-irritating gas. Oxygen is a colourless, odourless and tasteless gas. Nitrous oxide is not very soluble in water and has a low solubility in blood and tissues.

3 Pharmaceutical Form

Compressed colourless medical gas mixture (for medicinal use only).

4 Clinical Particulars

4.9 Overdose

Symptoms and signs. Inappropriate or deliberate inhalation of nitrous oxide will ultimately result in unconsciousness, passing through stages of increasing light-headedness and intoxication, and, if the person were to be within a confined space, death from anoxia could result.
Other signs may include: cyanosis, bradycardia, respiratory depression, cardiovascular depression and severe hypotension.
Treatment. There is no specific antidote. Treatment measures include: discontinuation of Nitronox, basic life support, assisted or controlled ventilatory support with oxygen and other symptomatic and supportive treatment.
Please consult the material safety data sheet for Nitronox from the sponsor.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.3 Preclinical Safety Data

Genotoxicity. Nitrous oxide gave mixed results in limited assays for genotoxicity. In assays for gene mutations nitrous oxide was negative in the Ames test and sex-linked recessive lethal assay in Drosophila melanogaster, but was positive in Chinese hamster lung cells. The potential to cause chromosomal damage has not been investigated. An increased frequency of chromosomal aberrations was observed in bone marrow cells and spermatogonia of rats treated with a mixture of nitrous oxide and halothane. Nitrous oxide also caused an increased incidence of sister chromatid exchanges (SCE) in human lymphocytes in vitro.
Clinical studies have suggested that nitrous oxide may be associated with genotoxic events. DNA strand breaks were reported in surgical patients treated with isoflurane-nitrous oxide-oxygen, 1 day after surgery. An increased frequency of SCE, but not micronuclei, was found in the lymphocytes of operating room personnel exposed to nitrous oxide and isoflurane. An increase in SCE was also found in operating room personnel exposed to halothane and nitrous oxide.
Carcinogenicity. Nitrous oxide was tested for carcinogenic potential in rats and mice. No carcinogenic effect was seen in mice exposed to nitrous oxide (40%, 4 hours per day) or rats exposed to low concentrations of halothane-nitrous oxide (10 ppm:500 ppm, 7 hours per day).

6 Pharmaceutical Particulars

6.7 Physicochemical Properties

Chemical structure. Nitrous oxide, N₂O is a linear but asymmetrical molecule of the form:
https://stagingapi.mims.com/au/public/v2/images/fullchemgif/CSNITROU.gif Oxygen has a molecular structure of:
https://stagingapi.mims.com/au/public/v2/images/fullchemgif/CSOXYGEN.gif Molecular weight: N₂O 44.01, oxygen 32.0.
Physical state in the cylinder: high pressure gas at ambient temperature.
Combustion characteristics: non-flammable, strongly supports combustion.
Chemical characteristics. Nitrous oxide and oxygen are oxidising substances which will support combustion of materials which may not normally burn in air. Nitrous oxide is stable and comparatively unreactive at ordinary temperatures and pressures. At elevated temperatures it decomposes to nitrogen and oxygen. Nitrous oxide will react with powerful reducing agents such as phosphine, stannous chloride and hydrogen. Rust and other impurities, especially oil and grease may cause ignitions.
CAS number. Nitrous oxide. CAS number 10024-97-2.
Oxygen. CAS number 7782-44-7.

7 Medicine Schedule (Poisons Standard)

(S4) Prescription Only Medicine.

Summary Table of Changes

https://stagingapi.mims.com/au/public/v2/images/fulltablegif/NITRONST.gif