Serynox

Package leaflet: Information for the user

Serynox, 50% + 50%, medicinal compressed gas
nitrous oxide + oxygen
Please read this leaflet carefully before using the medicine, as it contains
important information for the patient.

• Keep this leaflet for future reference.
• If you have any questions, please consult your doctor, pharmacist, or nurse.
• If you experience any adverse reactions, including any not listed in this leaflet, inform your doctor, pharmacist, or nurse. See section 4.

Leaflet contents

1. What Serynox is and what it is used for
2. What you need to know before using Serynox
3. How to use Serynox
4. Possible side effects
5. How to store Serynox
6. Contents of the pack and other information

1. What Serynox is and what it is used for

• Serynox contains a mixture of two medicinal gases:
• 50% nitrous oxide (medicinal "laughing gas"),
• 50% oxygen (medicinal oxygen).

It is administered by inhalation of the gas mixture. At this concentration, Serynox has no anaesthetic (numbing) effect.
Serynox belongs to a class of combination medicines containing nitrous oxide.
Serynox can be used in adults, adolescents, and children over 1 month of age.
The effect of Serynox is to reduce pain sensation and produce a feeling of relaxation during:

• short-term painful procedures or treatment of mild to moderate pain, and sedation during dental procedures, when rapid onset and offset of analgesic effect are desired.

2. Important information before using Serynox

When not to use Serynox

• if the patient has received intraocular gas during eye surgery, they must always inform their doctor to ensure administration does not lead to severe postoperative complications due to increased intraocular pressure,
• if the patient requires administration of 100% oxygen,
• in cases of increased intracranial pressure (intracranial hypertension),
• in cases of impaired consciousness (not fully normal mental status),
• in cases of diagnosed untreated vitamin B12 or folic acid deficiency,
• in cases of recent unexplained neurological disturbances,
• in patients with heart failure or cardiac disorders (e.g. following heart surgery).

During inhalation of Serynox, gas-filled cavities and body air spaces may expand and cause serious complications. Therefore, Serynox must not be used in the following conditions:

• head injury,
• facial or jaw injuries,
• accumulation of air between the lung and chest wall (pneumothorax),
• lung alveolar disease causing breathing difficulties (severe emphysema),
• formation of air bubbles in the bloodstream (air embolism),
• following deep diving with risk of decompression sickness,
• X-ray examination of the brain,
• middle ear, inner ear or sinus surgery,
• presence of air in the abdominal cavity causing significant abdominal discomfort,
• following spinal anesthesia to eliminate pain sensation from the waist downwards (epidural anesthesia) where air has been injected.

Warnings and precautions

Before starting treatment with Serynox, discuss this with your doctor.
Serynox should be administered only by trained personnel. However, self-administration under medical supervision is preferred to allow assessment of the patient's level of consciousness.
The patient must NEVER handle the cylinder containing Serynox.
Rooms where Serynox is used should be adequately ventilated and/or equipped with an exhaust system to maintain ambient nitrous oxide concentration at the lowest possible level.
The patient should breathe normally during inhalation of Serynox.
Use in newborns is not recommended.
If Serynox is administered to the mother during childbirth, newborns should be monitored for adverse effects, especially respiratory depression.
Prolonged or repeated administration of Serynox may lead to abuse and dependence.
Repeated or prolonged administration of Serynox may cause inactivation of vitamin B12 in the body. The physician may decide to prescribe vitamin B12 supplementation.
The following conditions require consultation with a doctor due to risk of vitamin B12 deficiency:

• if the patient has anaemia, a certain type of inflammation of the gastric mucosa (atrophic gastritis), or brain disease,
• if the patient is a vegetarian,
• if the patient is alcohol-dependent.

If the patient or child suffers from acute otitis media, inform the doctor.

Serynox and other medicines

Inform your doctor or pharmacist about all medicines currently used, recently taken, or planned for use.
Inform your doctor if:

• the patient has received an intraocular gas injection during eye surgery. There is a risk of postoperative complications if intraocular pressure becomes too high.
• the patient is taking medications acting on the central nervous system (such as morphine derivatives, benzodiazepines, and other psychotropic medicinal products), as these may enhance sedative effects.
• the patient is taking vitamin B12 and folic acid, as Serynox may inactivate vitamin B12.

Serynox may enhance methotrexate toxicity by interfering with folate metabolism.
Pulmonary toxicity associated with active substances such as bleomycin, amiodarone, nitrofurantoin, and similar antibiotics may be intensified by inhalation of higher oxygen concentrations.

Pregnancy, breastfeeding and fertility

If the patient is pregnant, breastfeeding, suspects she may be pregnant, or is planning to conceive, she should consult her doctor or pharmacist before using this medicine.
Serynox may be used during pregnancy if clinically indicated.
If used during the peripartum period, the newborn should be monitored for adverse effects.
However, interruption of breastfeeding is not necessary after short-term administration of Serynox.

Driving and operating machinery

Serynox affects perception and motor functions (cognitive and psychomotor functions).
After administration of Serynox, the patient will be monitored until all effects have subsided and until consciousness returns to the pre-administration level. Driving and operating machinery are psychomotor-demanding activities and are not recommended for a reasonable period after exposure to nitrous oxide.

3. How to use Serynox

Dosage
Only personnel trained in the use of this form of medication are authorized to administer Serynox. The doctor will explain how to use Serynox, how it works, and what effects its use may cause. For certain procedures, the patient may hold the device used to deliver the gas, allowing self-administration of the gas.
During administration of Serynox, the patient and the delivery of the medication will be continuously monitored to ensure safe use.
If the patient loses verbal contact, administration of Serynox must not be continued.
Maximum analgesic effect is achieved after at least 3 minutes.

Method of administration
Serynox is intended for inhalation.
Serynox is a mixture of two medical gases which the patient inhales through a face mask using an appropriate delivery device.
During inhalation of Serynox, the patient should breathe normally.
After administration of Serynox, the mask should be removed, and the patient should rest and wait until full consciousness is regained.

Duration of treatment
The use of Serynox depends on the duration of the procedure and usually should not exceed 60 minutes of inhalation per day. Repeated administration of Serynox should not continue for longer than 15 days.

Overdose of Serynox
The likelihood of a patient receiving an excessive amount of gas is very low, as the patient controls the amount of gas inhaled through the mask and is closely monitored.
If the patient breathes faster than usual and consequently inhales more nitrous oxide than would occur during normal breathing, they may feel significant fatigue and experience a sensation of partial disconnection from the surroundings.
In such a case, medical personnel must be informed immediately and administration should be stopped.
If the patient's skin turns blue (cyanosis) during administration of Serynox, treatment must be discontinued immediately. If cyanosis does not resolve quickly, the patient will be ventilated using a manual resuscitation bag filled with air or oxygen.

Discontinuation of Serynox
Analgesic effects cease immediately after stopping administration of Serynox, with no irreversible effects.
If you have any further questions about the use of this medicine, consult your doctor or pharmacist.

4. Possible adverse effects

Like all medicines, this medicine can cause adverse effects, although not everyone will experience them.
The following adverse effects may occur during treatment and usually resolve within a few
minutes after the end of the inhalation of the mixture:

Common: may affect up to 1 in 10 people

• dizziness,
• fainting,
• nausea,
• vomiting.

Uncommon: may affect up to 1 in 100 people

• tingling *(paraesthesia)*,
• increased sedation *(drowsiness)*,
• hallucinations,
• anxiety,
• excitement,
• euphoria,
• dreams.

Unknown: frequency cannot be estimated from available data

• headache,
• seizures,
• increased intracranial pressure (see section 2 - When not to use Serynox),
• ear pain,
• psychosis,
• confusion,
• disorientation,
• respiratory depression (in newborns during childbirth),
• severe visual disturbances (caused by increased gas volume in the eyeball, see section 2 - When not to use Serynox).

After prolonged or repeated exposure to Serynox
Unknown: frequency cannot be estimated from available data
Abnormal movements may occur during hyperventilation during inhalation.
Neurological disorders, such as spinal cord diseases *(myeloneuropathies).
Decreased number of red blood cells accompanied by decreased number of white blood cells
*(megaloblastic anaemia with leukopenia).
Abuse and dependence.
Vitamin B12 deficiency (see section 2 - When not to use Serynox, Warnings and precautions, Serynox and other medicines).

Reporting of adverse effects
If any adverse effects occur, including any adverse effects not listed in this leaflet, inform your doctor, pharmacist, or nurse. Adverse effects can be reported directly to the Department of Monitoring Adverse Drug Reactions of the Office for Registration of Medicinal Products, Medical Devices and Biocidal Products
Al. Jerozolimskie 181C
PL-02 222 Warsaw
Tel.: + 48 22 49 21 301
Fax: + 48 22 49 21 309
Website: https://smz.ezdrowie.gov.pl
Adverse effects can also be reported to the marketing authorization holder.
Reporting adverse effects helps to provide more information on the safety of the medicine.

5. How to store Serynox

The medicine should be stored out of sight and reach of children.
Do not use this medicine after the expiry date stated on the gas cylinder, following the abbreviation
EXP.
Storage of gas cylinders
Gas cylinders must be stored as follows:
Securely fastened gas cylinders must be stored in an UPRIGHT POSITION (full cylinders,
cylinders in use, full cylinders for transport within healthcare facilities and vehicles, and empty cylinders).
There are no special requirements regarding the storage temperature of the medicine.
Different types of medical gases must be kept separate from each other. Full and empty gas cylinders must
be stored separately.
Storage of full cylinders in a designated storage area for gas cylinders
Full cylinders must be stored in an UPRIGHT POSITION in a clean, well-ventilated area,
free from any flammable materials and protected from weather conditions.
The storage area must be reserved exclusively for medical gases and kept closed.
Empty and full cylinders must be stored separately.
Full cylinders must be protected from overturning and dropping, and kept away from sources of heat,
ignition, and flammable substances. They must also be protected from weather conditions,
particularly from cold. After delivery by the manufacturer, cylinders must have intact seals
that clearly indicate any tampering.
Transport of full cylinders
Within healthcare facilities, full cylinders must be securely fastened in an UPRIGHT POSITION
using appropriate means (hand trolleys with chains, straps, or clamps) during transport, to protect them
from shocks and falls. During transport in vehicles, full cylinders must be securely fastened in an
UPRIGHT POSITION. Emergency services must be informed that cylinders must be protected from cold
both during transport in vehicles and when used outdoors. Particular care must be taken with the pressure regulator connection, especially for cylinders with residual pressure valves, to avoid accidental damage.
Storage of empty cylinders
Empty cylinders must be stored securely fastened in an UPRIGHT POSITION.
Valves must be closed.

6. Contents of the package and other information

What Serynox contains

• The active substances in the medicine are: 50% nitrous oxide and 50% oxygen
• Serynox does not contain any other ingredients.

What Serynox looks like and contents of the pack
Serynox is a colourless compressed medical gas.
2-litre, 5-litre, 10-litre, 15-litre and 20-litre aluminium or steel gas cylinders
(identified by a blue-white shoulder and a white body), filled under a pressure of 170 bar,
equipped with a residual pressure valve or valves with integrated pressure regulator, both
featuring a special outlet connection.

Not all pack sizes may be marketed.
Marketing Authorisation Holder and Manufacturer
Marketing Authorisation Holder
Messer Polska Sp. z o.o.
ul. Maciejkowicka 30
41-503 Chorzów
Poland
Manufacturer
MESSER FRANCE
ZI Lafayette, 35 rue de l'Europe
38790 Saint-Georges-d'Espéranche
France
This medicinal product is authorised for marketing in the Member States of the European
Economic Area under the following names:
Austria, Germany: Serynox 50% / 50% Gas zur medizinischen Anwendung, druckverdichtet
Belgium: Placynox 50% / 50% v/v medicinaal gas, samengeperst / gaz médicinal comprimé
Croatia: Serynox 50%/50% V/V medicinski plin, stlačen
Czech Republic: Serynox
Estonia, Latvia, Lithuania: Serynox
France: Placynox 50% / 50% gaz médicinal comprimé
Poland: Serynox
Romania: Serynox 50% / 50% Gaz medicinal comprimat
Slovenia: Serynox 50 %/50 % V/V medicinski plin, stisnjeni
Slovakia: Serynox 50% / 50% stlačený medicinálny plyn
Spain: Serynox 50% / 50% gas comprimido medicinal

Information intended exclusively for healthcare professionals

Serynox gas cylinders must be used solely for medical purposes.
Preparation of full cylinders 48 hours prior to use
The mixture is unstable at temperatures below -5°C. Further cooling may lead to
condensation of part of the nitrous oxide, resulting in delivery of an uneven gas mixture
containing too much oxygen (a mixture with reduced analgesic effect) at the beginning of
treatment and too much nitrous oxide (a hypoxic mixture) at the end of treatment. For this reason,
before first use, full cylinders must be stored horizontally for at least 48 hours
at a temperature above +10°C, in a buffer zone in the pharmacy and/or on the ward where the medicinal product is administered. Cylinders should be placed in a location where they are not at risk of
being tipped over and away from heat sources, ignition sources, and flammable materials. Cylinder valves should be closed.
Before use, place the gas cylinder in an upright position.
Rooms where Serynox is frequently used must be equipped with an appropriate system for evacuation of waste gases or ventilation.
Different types of medical gases must be stored separately. Full and empty gas cylinders must be stored apart.
Never use oils or greases, even if there is difficulty turning the cylinder valve or connecting the regulator. Valves and remaining equipment must be handled with clean, grease-free hands (free from hand creams, etc.).
Close the cylinder valve in case of fire or when not in use. In case of fire risk,
move the gas cylinder to a safe location.
Use only standard equipment designed for the 50% N\ O + 50% O \ gas mixture.
Ensure that cylinders are sealed before being handed over for first use.
Smoking and the use of open flames are strictly prohibited in rooms where treatment with Serynox is administered.
During use, the cylinder must be secured on an appropriate holder.
After use, close the cylinder valve manually. Release pressure from the regulator or connection.
Do not dispose of empty gas cylinders. Empty gas cylinders will be collected by the supplier.