How to use Gnak
Contents of the leaflet
- Leaflet accompanying the packaging: information for the user
- GNAK, solution for infusion
- What is GNAK and what is it used for
- Important information before taking GNAK
- How to take GNAK
- Possible side effects
- How to store GNAK
- Contents of the pack and other information
- What GNAK contains
- What GNAK looks like and contents of the pack
- Marketing authorization holder and manufacturer
- This medicine is authorized in the Member States of the European Economic Area and in the United Kingdom (Northern Ireland) under the following names:
- Information intended for healthcare professionals only:
Leaflet accompanying the packaging: information for the user
GNAK, solution for infusion
Active substances: glucose, sodium chloride, sodium acetate trihydrate, potassium chloride, magnesium chloride hexahydrate
You should carefully read the contents of the leaflet before administering the medicine, as it contains important information for the patient.
- You should keep this leaflet, so that you can read it again if you need to.
- If you have any further questions, ask your doctor or nurse.
- If you experience any side effects, including any not listed in this leaflet, you should tell your doctor or nurse. See section 4.
In this leaflet, GNAK, solution for infusion will be referred to as GNAK.
Table of contents of the leaflet
- 1. What is GNAK and what is it used for
- 2. Important information before taking GNAK
- 3. How to take GNAK
- 4. Possible side effects
- 5. How to store GNAK
- 6. Contents of the pack and other information
1. What is GNAK and what is it used for
GNAK is an aqueous solution of the following substances:
- sugar (glucose),
- sodium chloride,
- sodium acetate trihydrate,
- potassium chloride,
- magnesium chloride hexahydrate.
Glucose is one of the sources of energy for the body. This infusion solution provides 200 kilocalories per liter. Sodium, potassium, magnesium, chloride, and acetate are chemical substances found in the blood. GNAK is used as a source of fluids and chemicals, and as a source of carbohydrates (sugar), if the patient is unable to eat or drink normally.
2. Important information before taking GNAK
DO NOT use GNAK if the patient has any of the following conditions:
- higher than normal potassium levels in the blood (hyperkalemia);
- severe kidney function disorders (renal failure), resulting in too little urine being produced (oliguria) or no urine being produced at all (anuria);
- heart or lung failure (uncompensated heart or respiratory failure);
- untreated diabetes, with blood sugar levels above normal (uncontrolled diabetes);
- states of glucose intolerance;
- loss of consciousness (hyperosmolar coma). This is a type of coma that can occur in a diabetic patient who is not receiving enough medication;
- higher than normal blood sugar levels (hyperglycemia);
- higher than normal blood lactate levels (hyperlactatemia);
- allergy to potassium chloride, sodium acetate trihydrate, sodium chloride, magnesium chloride hexahydrate, glucose, or any of the other ingredients of this medicine (listed in section 6).
Warning and precautions
You should tell your doctor if you have or have had any of the following conditions:
- allergy to corn, as GNAK contains sugar derived from corn, see "Possible side effects";
- heart failure, severe heart rhythm disorders, or other heart diseases;
- lung disease (respiratory failure);
- kidney failure or kidney function disorders;
- a large amount of fluid in the body or fluid accumulation in the lungs or under the skin, especially around the ankles;
- high blood pressure;
- high blood pressure during pregnancy (pre-eclampsia or eclampsia);
- a disease that causes increased activity of a hormone called aldosterone (aldosteronism);
- any other conditions associated with excessive sodium retention in the body, such as steroid treatment (see also "GNAK and other medicines");
- conditions that increase the risk of high potassium levels in the blood, such as:
- kidney failure,
- adrenal gland disease (adrenal insufficiency),
- sudden loss of body water due to e.g. vomiting or diarrhea,
- severe burns or other causes of extensive tissue damage;
- low calcium levels in the blood;
- a disease that causes progressive muscle weakness (myasthenia);
- recently undergone surgery with the use of muscle relaxants (neuromuscular blockade) used during surgical operations and administered under the control of an anesthesiologist;
- blood pH disorders;
- head injury within the last 24 hours - GNAK should not be used;
- increased intracranial pressure;
- stroke caused by a blood clot in a blood vessel in the brain (ischemic stroke);
- malnutrition due to starvation or poor nutrition;
- diabetes or glucose tolerance disorders;
- if the patient has an abnormal amount of cerebrospinal fluid (e.g. due to meningitis, cerebral hemorrhage, or brain injury);
- conditions that may cause high activity of vasopressin - a hormone that regulates fluid content in the body, such as:
- sudden and severe illness or injury,
- recent surgery,
- brain disease,
- taking certain medications. These conditions may increase the risk of low sodium levels in the blood, which can lead to headache, nausea, lethargy, coma, or brain edema.
During the administration of this infusion, the doctor will take blood and urine samples to examine:
- fluid balance and the amount of chemicals such as sodium, potassium, and magnesium in the blood and urine (electrolytes in serum and urine);
- blood and urine acidity (acid-base balance).
GNAK contains sugar (glucose) and may cause an increase in blood sugar levels (hyperglycemia). This is especially important in patients with diabetes. In such cases, the doctor may:
- adjust the infusion rate;
- administer insulin to reduce blood sugar levels.
If long-term treatment with GNAK is required, the doctor will also administer other types of infusions to the patient. These will meet the body's needs for other chemical and nutritional components.
Children
Special caution and close monitoring are required when administering GNAK to children. Newborns, especially premature and low-birth-weight infants, are more susceptible to low or high blood sugar levels due to glucose infusion. Low blood sugar levels in newborns can cause prolonged seizures, coma, and brain damage. High blood sugar levels are associated with brain hemorrhage, later onset of bacterial and fungal infections, gastrointestinal infections, visual impairment, respiratory disorders, prolonged hospital stay, and death. Children and adolescents should be closely monitored. In cases where normal regulation of water content in the blood is disrupted by increased secretion of antidiuretic hormone (ADH), infusion of fluids with low sodium chloride concentration may lead to low sodium levels in the blood (hyponatremia). This can cause headache, nausea, seizures, lethargy, coma, brain edema, and death, so these symptoms are considered a medical emergency.
GNAK and other medicines
You should tell your doctor or nurse about all medicines you are taking or have recently taken, as well as any medicines you plan to take. It is not recommendedto take the following medicines while taking GNAK:
- muscle relaxants (e.g. tubocurarine, suxamethonium, and vecuronium), which are used during surgical operations under the control of an anesthesiologist.
Other medicines that may interact with GNAK or be affected by it:
- anti-inflammatory medicines (corticosteroids);
- an anti-inflammatory medicine used to treat stomach ulcers (carbenoxolone);
- certain diuretics, known as potassium-sparing diuretics (e.g. amiloride, spironolactone, triamterene);
- angiotensin-converting enzyme (ACE) inhibitors (used to treat high blood pressure);
- angiotensin II receptor blockers (used to treat high blood pressure);
- tacrolimus (used to prevent transplant rejection and treat certain skin diseases);
- cyclosporin (used to prevent transplant rejection);
- medicines with an acidic pH, such as:
- salicylates (used to treat inflammatory conditions) (aspirin);
- barbiturates (sleeping pills);
- lithium (used to treat psychiatric disorders);
- medicines with a basic pH, including:
- sympathomimetics (such as ephedrine and pseudoephedrine, used e.g. in cough preparations);
- stimulants (such as quinidine, dexamphetamine sulfate (used to treat ADHD), fenfluramine hydrochloride (used to treat obesity)).
Taking certain medicines may increase the risk of side effects due to low sodium levels in the blood. These medicines include:
- diuretics;
- pain relievers and/or anti-inflammatory medicines (also known as NSAIDs);
- antipsychotic medicines;
- medicines used to treat depression (selective serotonin reuptake inhibitors);
- medicines that produce effects similar to morphine (opioids);
- certain medicines used to treat epilepsy (antiepileptic medicines);
- a hormone called oxytocin (causes uterine contractions);
- certain medicines used to treat cancer (chemotherapy).
Using GNAK with food and drink
You should ask your doctor what you can eat or drink.
Pregnancy, breastfeeding, and fertility
If you are pregnant or breastfeeding, think you may be pregnant, or plan to have a child, ask your doctor for advice before taking this medicine. The doctor will decide whether you can take GNAK if you are pregnant or breastfeeding.
Driving and using machines
This medicine does not affect your ability to drive or use machines.
3. How to take GNAK
GNAK is administered by a doctor or nurse. The dose of the medicine and the duration of administration are determined by the doctor. This depends on the patient's age, weight, and clinical condition, as well as any concurrent treatment. The doctor may check the levels of salts (electrolytes) and sugar (glucose) in the blood.
DO NOT use GNAK if it contains visible particles or if the packaging is damaged in any way.
GNAK is usually administered through a plastic tube connected to a needle inserted into a vein. Typically, this solution is administered into a vein in the arm. However, the doctor may order a different method of administration. GNAK MUST NOT be administered under the skin (subcutaneously). Any unused solution should be discarded. GNAK MUST NOT be administered from a partially used bag. Due to the glucose content, this solution MUST NOT be administered through the same infusion set as whole blood (blood transfusion). This may cause damage or clumping of red blood cells.
Overdose of GNAK
In case of administration of too much GNAK (overdose) or too rapid administration, the following symptoms may occur:
- fluid and/or sodium overload with fluid accumulation (edema) in tissues, causing swelling;
- high blood sugar levels (hyperglycemia);
- a feeling of tingling in the upper and lower limbs (paresthesia);
- muscle weakness;
- inability to move (paralysis);
- irregular heartbeat (arrhythmia);
- heart block (very slow heartbeat);
- cardiac arrest (the heart stops beating; a life-threatening condition);
- a state of confusion;
- decreased tendon reflexes;
- decreased depth and frequency of breathing (respiratory depression);
- nausea (vomiting);
- vomiting;
- redness of the skin;
- thirst;
- low blood pressure (hypotension);
- drowsiness;
- slow heartbeat (bradycardia);
- coma (loss of consciousness);
- acidosis of the blood (leading to fatigue, confusion, lethargy, and increased breathing rate);
- mood changes;
- fatigue;
- shortness of breath;
- muscle stiffness;
- muscle tremors;
- muscle cramps (tetany);
- high magnesium levels in the blood.
If you experience any of these symptoms, you should immediately inform your doctor. The infusion will be stopped, and the doctor will treat the symptoms accordingly. If another medicine has been added to GNAK and an overdose has occurred, this additional medicine may also cause symptoms. You should read the Patient Information Leaflet accompanying the added medicine to learn about possible symptoms.
Stopping GNAK
The decision to stop the infusion is made by the doctor. If you have any further questions about the use of this medicine, ask your doctor or nurse.
4. Possible side effects
Like all medicines, GNAK can cause side effects, although not everybody gets them. The frequency of side effects is unknown (cannot be estimated from the available data).You should immediately inform your doctor or nurse if you experience any of the following symptoms. These may be symptoms of a very severe or even life-threatening allergic reaction (hypersensitivity):
- swelling of the skin on the face, lips, and throat;
- difficulty breathing;
- skin rash;
- redness of the skin (flushing);
- allergic reactions, including a severe allergic reaction called anaphylaxis, potential symptoms in patients with corn allergy.
Treatment will depend on the symptoms.
Other side effects:
- reactions related to the infusion technique:
- fever;
- infection at the infusion site;
- local pain or reaction (redness or swelling) at the infusion site;
- irritation or inflammation of the vein into which the solution is administered. This can cause redness, pain, or burning, as well as swelling along the vein into which the solution is administered;
- formation of blood clots (thrombophlebitis), which may be accompanied by inflammation. This causes pain, swelling, or redness;
- leakage of the solution into the space surrounding the blood vessels (extravasation);
- high potassium levels in the blood, which can cause abnormal heart rhythm (hyperkalemia);
- high blood sugar levels (hyperglycemia);
- fluid accumulation in the body (hypervolemia);
- disorders of salt levels in the blood (electrolyte disturbances);
- seizures;
- low sodium levels in the blood (hyponatremia);
- brain edema, which can cause brain damage (hyponatremic encephalopathy).
If another medicine has been added to the infusion solution, it may also cause side effects. These will depend on the medicine added. You should read the Patient Information Leaflet accompanying the added medicine to learn about possible symptoms.
Reporting side effects
If you experience any side effects, including any not listed in this leaflet, you should tell your doctor or nurse. Side effects can be reported directly to the Department of Monitoring of Adverse Reactions to Medicinal Products, Office for Registration of Medicinal Products, Medical Devices, and Biocidal Products, Al. Jerozolimskie 181C, 02-222 Warsaw, tel.: +48 22 49 21 301, fax: +48 22 49 21 309, website: https://smz.ezdrowie.gov.pl. Side effects can also be reported to the marketing authorization holder. By reporting side effects, you can help provide more information on the safety of this medicine.
5. How to store GNAK
The medicine should be stored out of sight and reach of children. DO NOT use GNAK after the expiry date stated on the bag after "Expiry date". The expiry date refers to the last day of the month stated. DO NOT store above 25°C. DO NOT use GNAK if it contains visible particles or if the packaging is damaged in any way.
6. Contents of the pack and other information
What GNAK contains
The active substances of GNAK are:
- glucose (monohydrate): 50 g per liter
- sodium chloride: 1 g per liter
- sodium acetate trihydrate: 3.13 g per liter
- potassium chloride: 1.50 g per liter
- magnesium chloride hexahydrate: 0.30 g per liter
Other ingredients are:
- hydrochloric acid (to adjust pH)
- water for injections
What GNAK looks like and contents of the pack
GNAK, solution for infusion is a clear solution, free from visible particles. It is available in polyolefin-polyamide plastic bags (Viaflo). Each bag is placed in a closed, protective, outer plastic packaging. Bag size: 1000 ml. Bags are supplied in cardboard boxes. Each cardboard box contains one of the following numbers of bags:
- 10 bags of 1000 ml
- 12 bags of 1000 ml
Marketing authorization holder and manufacturer
Marketing authorization holder: Baxter Polska Sp. z o.o., ul. Kruczkowskiego 8, 00-380 Warsaw. Manufacturer: Bieffe Medital Sabiñànigo, Ctra de Biescas-Senegüe, 22666 Sabiñanigo (Huesca), Spain.
This medicine is authorized in the Member States of the European Economic Area and in the United Kingdom (Northern Ireland) under the following names:
Bulgaria: GNAK 50 mg/ml solution for infusion, Croatia: GNAK 50 mg/ml solution for infusion, Czech Republic: GNAK 50 mg/ml infusion solution, Cyprus: Maintelyte 50 mg/ml solution for infusion, Denmark: Glucose-Na-K Baxter 50 mg/ml, infusion fluid, solution, Spain: Maintelyte Solution for perfusion, Finland: Glucose-Na-K Baxter 50 mg/ml infusion fluid, solution, France: MAINTELYTE solution for perfusion, Greece: Maintelyte 50 mg/ml solution for infusion, Germany: Maintelyte 50 mg/ml Infusion solution, Ireland: Maintelyte solution for infusion, Italy: GNAK 50 mg/ml Solution for infusion, Malta: Maintelyte solution for Infusion, Netherlands: Maintelyte, solution for infusion, Poland: GNAK, Portugal: GNAK 50 mg/ml Solution for perfusion, Romania: GNAK 50 mg/ml Solution for infusion, Slovenia: GNAK solution for infusion, Slovakia: GNAK 50 mg/ml Infusion solution, Sweden: Glucose-Na-K Baxter 50 mg/ml infusion fluid, solution, United Kingdom (NI): Maintelyte solution for infusion. Date of last revision of the leaflet:March 2024. Baxter and Viaflo are trademarks of Baxter International Inc.
---------------------------------------------------------------------------------------------------------------------------Information intended for healthcare professionals only:
Only use if the solution is clear, free from visible particles, and the container is undamaged. Administer immediately after connecting the infusion set. Do not remove the bag from the protective packaging until use. The inner bag ensures the sterility of the product. Plastic containers should not be connected in series. Such use could cause air embolism due to residual air drawn from the first container before the fluid administration from the second container is completed. Applying additional pressure on intravenous solutions contained in flexible plastic containers to increase the flow rate may cause air embolism if the container is not completely emptied of air before administration. Using infusion sets with air vents, with the air vent valve in the open position, may cause air embolism. Do not use infusion sets with air vents, with the air vent valve in the open position, with flexible plastic containers. The solution should be administered using sterile equipment and following aseptic principles. The infusion set should be pre-filled with the solution to prevent air from entering the system. Additional medicines can be added to the solution before infusion or during infusion through a self-sealing port for adding medicines. Adding medicines before administration: a. Disinfect the port for adding medicines. b. Using a syringe with a needle from 19G (1.10 mm) to 22G (0.70 mm), insert the needle into the self-sealing port for adding medicines and inject the medicine. c. Mix the solution with the medicine thoroughly. In the case of preparations with high density, such as potassium chloride, gently tap the ports with the bag in the upright position and mix. Note: Do not store bags containing added medicines. Adding medicines during administration: a. Close the infusion set clamp. b. Disinfect the port for adding medicines. c. Using a syringe with a needle from 19G (1.10 mm) to 22G (0.70 mm), insert the needle into the self-sealing port for adding medicines and inject the medicine. d. Remove the container from the stand and/or turn it upside down. e. Empty both ports by gently tapping, holding the bag upside down. f. Mix the solution with the medicine thoroughly. g. Return the container to its previous position, re-open the clamp, and continue administration.
- 4. Shelf life during use: Added medicines: Before use, the chemical and physical stability of each added medicine should be established in the pH of the GNAK solution in the Viaflo container.
From a microbiological point of view, the diluted product should be used immediately. If the solution is not used immediately, the user is responsible for the time and conditions of storage until use, and storage should not exceed 24 hours, at a temperature between 2°C and 8°C, unless the dilution has taken place in controlled and validated aseptic conditions.
- 5. Incompatibility of added medicines Before adding a medicine to the solution in the Viaflo container, the possibility of incompatibility should be assessed.
This solution should not be mixed with other medicines without compatibility testing. You should read the instructions for the medicine to be added to the solution. Before adding the medicine, you should check if it is soluble and stable in water with a pH corresponding to the GNAK solution (pH 4.5-6.5). GNAK solutions are incompatible with blood or red blood cells, and cases of clot formation have been reported. Do not use additional medicines known to be incompatible. Baxter and Viaflo are trademarks of Baxter International Inc.
- Country of registration
- Dosage formSolution, -
- ATC codeB05BB02
- Active substance
- Prescription requiredYes
- Manufacturer
- ImporterBieffe Medital Saabinanigo
- This information is for reference only and does not constitute medical advice. Always consult a doctor before taking any medication. Oladoctor is not responsible for medical decisions based on this content.
- Alternatives to GnakDosage form: Solution, -Active substance: electrolytes with carbohydratesManufacturer: Fresenius Kabi Polska Sp. z o.o.Prescription not requiredDosage form: Solution, 33 g/l + 3 g/lActive substance: electrolytes with carbohydratesManufacturer: Baxter S.A. Bieff Medital S.A.Prescription requiredDosage form: Solution, (1.5 mg + 50 mg)/mlActive substance: electrolytes with carbohydratesPrescription not required
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Frequently Asked Questions
Gnak requires a prescription in Poland. You can check with a doctor online whether this medicine may be appropriate for your situation.
The active ingredient in Gnak is electrolytes with carbohydrates. This information helps identify medicines with the same composition but different brand names.
Gnak is manufactured by Bieffe Medital Saabinanigo. Pharmacy brands and packaging may differ depending on the distributor.
Doctors such as Family doctors, Psychiatrists, Dermatologists, Cardiologists, Endocrinologists, Gastroenterologists, Pulmonologists, Nephrologists, Rheumatologists, Hematologists, Infectious disease physicians, Allergists, Geriatricians, Paediatricians, Oncologists may assess whether Gnak is appropriate, depending on your situation and local regulations. You can book an online consultation to discuss your symptoms and possible next steps.
Spain has a well-developed healthcare infrastructure across major cities such as Madrid, Barcelona, Valencia, and Seville. Pharmacies are widely available and operate under strict regulations, ensuring access to prescribed medications.
You can buy Gnak in Madrid, Barcelona, Seville, or Valencia at any local pharmacy with a valid prescription.
To obtain a prescription, you can use Oladoctor:
Other medicines with the same active substance (electrolytes with carbohydrates) include Benelite, Iniectio Glucosi 5 % + Natrii Hlorati 0,9 % 2:1 Viaflo, Kalii hloridum 0,15% + Glucosum 5% Kabi. These may have different brand names or formulations but contain the same therapeutic ingredient. Always consult a doctor before switching or starting a new medicine.
















