Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
NACSYS 600mg Effervescent Tablets
⚠ This medicine appears to have been discontinued
The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.
If you were prescribed this medicine, other products containing Acetylcysteine may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.
What it is and what it is used for
FOR
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Acetylcysteine breaks down and loosens thick phlegm, making it runny and easy to cough up. Acetylcysteine is used in the treatment of airway diseases such as bronchitis (inflammation of the mucous membranes in the airways), emphysema, mucoviscidosis (cystic fibrosis) and bronchiectasis (chronic widening of an airway passage). NACSYS 600 mg Effervescent tablets are only indicated for adults.
What you need to know before you take it
E NACSYS 600 MG EFFERVESCENT TABLETS
Do not take NACSYS 600 mg effervescent tablets
- If you are allergic to acetylcysteine or any of the other ingredients of this medicine (listed in section 6).
- Children under 2 years of age must not take this medicine.
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Warnings and precautions Talk to your doctor or pharmacist before taking NACSYS 600 mg effervescent tablets:
- Acetylcysteine can cause shortness of breath due to muscle cramping of the airways (bronchospasms) especially in patients with asthma. If this occurs, immediately stop the treatment and consult a doctor.
- If you have or have had a peptic ulcer, as NACSYS 600 mg effervescent tablets may irritate your gastric wall. In particular if you use other drugs known to irritate the gastric wall.
- There have been very rare reports of serious hypersensitivity reactions with (high) fever, skin redness, joint pains and/or eye infection (Stevens-Johnson syndrome), and acute hypersensitivity reactions accompanied by fever and blisters on the skin or peeling of the skin (Lyell syndrome) which were associated with the use of NACSYS 600 mg effervescent tablets. However, in most cases, at least one other medicine was used, which was most likely the cause for this reaction. If new changes to the skin or mucous membranes occur, you must immediately consult a doctor and stop using acetylcysteine.
- As the thick phlegm becomes more fluid, its volume will increase, especially at the beginning of the treatment. If you are unable to efficiently cough up this fluid phlegm, you must consult a doctor so that adequate measures can be taken to remove the phlegm.
- Medicines, such as NACSYS that dissolve phlegm (mucolytics) may block the airways of children under the age of 2, due to the characteristics of the airways in this age group. This may limit their ability to cough up phlegm. Therefore, NACSYS must not be used by children under the age of 2.
- NACSYS 600 mg effervescent tablets are not suitable for use in children and adolescents younger than 18.
- When opening the package you may perceive a mild sulfur odour (smell of rotten eggs). This is a property of the active ingredient and is normal. It does not indicate that the medicine has changed. Consult your doctor if any of the above mentioned warnings apply to you or have applied to you in the past. Other medicines and NACSYS 600 mg effervescent tablets Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.
If you are using other medicines, do not dissolve them together with NACSYS 600 mg effervescent tablets.
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If you need to use medicines to control or prevent infections (antibiotics), you are advised to take these two hours before or after NACSYS 600 mg effervescent tablets. Cough suppressants should not be used at the same time as NACSYS 600 mg effervescent tablets, as you must be able to cough up the loosened phlegm. NACSYS 600 mg effervescent tablets may increase the blood pressure-lowering effect of nitroglycerin (a medicine used against tight painful feeling in the chest (angina pectoris)). Caution is advised.
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If you use activated charcoal (a medicine for traveller's diarrhoea), it may decrease the effect of NACSYS 600 mg effervescent tablets. Pregnancy and breast-feeding Pregnancy There is a limited amount of data from the use of acetylcysteine in pregnant women.
Animal studies do not indicate direct or indirect harmful effects on pregnancy, or the development of the child, before, during or after birth. Only use NACSYS 600 mg effervescent tablets after careful consideration of the benefits and risks during pregnancy.
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Breast-feeding It is not known whether acetylcysteine is excreted in breast milk. Only use NACSYS 600 mg effervescent tablets after careful consideration of the benefits and risks during breast-feeding. If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.
Driving and using machines There are no data available on the effect of acetylcysteine on the ability to drive. An effect is, however, unlikely.
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NACSYS 600 mg effervescent tablets contain sodium This medicine contains 115 mg sodium (main component of cooking / table salt) in each tablet. This is equivalent to 5.75% of the recommended maximum daily dietary intake of sodium for an adult.
How to take it
NACSYS 600 MG EFFERVESCENT TABLETS
Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.
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Adults: The recommended dose is 1 effervescent tablet once daily.
Patients who have difficulty coughing up phlegm (elderly and weakened patients), are advised to take the effervescent tablet in the mornings. Dissolve the effervescent tablet in half a glass of water. Drink the solution immediately. Do not use this medicine for longer than 14 days without consulting a doctor.
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If you take more NACSYS 600 mg effervescent tablets than you should Symptoms that may occur are: nausea, vomiting and diarrhoea. If you have taken too many NACSYS 600 mg effervescent tablets, immediately contact your doctor or pharmacist.
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BACK If you forget to take NACSYS 600 mg effervescent tablets If you have forgotten to take a dose and it is almost time for the next dose, do not take the 'forgotten' dose, but continue the schedule as given under "How to take NACSYS 600 mg effervescent tablets." Do not take a double dose to make up for a forgotten dose. If you have any further questions on the use of this medicine, ask your doctor or pharmacist.
Possible side effects
Like all medicines, this medicine can cause side effects, although not everybody gets them.
If any of the following side effects occur, immediately stop using NACSYS 600 mg effervescent tablets and contact your doctor or go to the emergency department of a nearby hospital.
- Shock (severe drop in blood pressure, paleness, restlessness, weak pulse, clammy skin, decreased consciousness) due to a sudden widening of the blood vessels as a result of severe hypersensitivity to certain ingredients (anaphylactic shock).
- Sudden fluid accumulation in the skin and mucous membranes (e.g. throat or tongue), breathing difficulties and/or itching and skin rash, often as a result of an allergic reaction (angioedema). The above mentioned reactions are very serious side effects. If you experience any of these reactions it is possible that you have a hypersensitivity reaction to NACSYS 600 mg effervescent tablets. You will require emergency medical care or need to be admitted to hospital.
This very serious side effect is very rare (occurs in fewer than 1 in 10,000 users). Bleedings are also very rare. Inform your doctor if you experience any of the following side effects:
- Shortness of breath due to muscle cramping of the airways (bronchospasms).
- Difficulty breathing, shortness of breath or breathlessness (dyspnoea).
- Impaired digestion with symptoms of fullness in the upper abdomen, gastric pain, belching, nausea and heartburn (dyspepsia). These side effects are rare (occurring in 1 to 10 in every 10,000 users).
- Hypersensitivity. This may manifest itself as bronchospasms and dyspnoea (see above), rapid heart rate (tachycardia), itching (pruritus), skin rash with severe itching and small bumps (urticaria) and angioedema.
- Headache
- Ringing in the ears (tinnitus)
- Inflammation of the oral mucous lining (stomatitis)
- Diarrhoea
- Fever (pyrexia)
- Low blood pressure
- Abdominal pain
- Nausea
- Vomiting These side effects are uncommon (occurring in 1 to 10 in every 1,000 users). If you suffer from gastric or duodenal ulcers or have had these in the past, acetylcysteine may have an unfavourable effect on your gastrointestinal mucous membrane.
If any of the side effects become serious, or you notice any side effects not mentioned in this leaflet, contact your doctor or pharmacist. Consult with your doctor or pharmacist if you notice that the effect of NACSYS 600 mg effervescent tablets is too strong or not strong enough.
Reporting of side effects If you get any side effects, talk to your doctor or pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via Yellow Card Scheme at www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.
How to store it
NACSYS 600 MG EFFERVESCENT TABLETS Keep this medicine out of the sight and reach of children. Store in the original package to protect against moisture.
Shelf life Do not use this medicine after the expiry date, which is stated on the label and carton package after EXP. The expiry date refers to the last day of that month.
After first opening the product may be used for a maximum of 10 days in tubes with 10 effervescent tablets or 20 days in tubes with 20 effervescent tablets.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
Contents of the pack and other information
What NACSYS 600 mg effervescent tablets contain The active substance is acetylcysteine.
The other ingredients are sodium hydrogen carbonate (E500) (equivalent to 115 mg sodium), citric acid (E330), sucralose (E955), and orange flavour (contains Orange Essential Oil, Orange Essential Oil terpenless, gum arabic (E414), butylated hydroxyanisole (E320), citric acid monohydrate (E330), and maltodextrin).
What NACSYS 600 mg effervescent tablets look like and contents of the pack NACSYS 600 mg effervescent tablets are round, flat, white to yellowish effervescent tablets. The tablets are packaged in a propylene tube with a polyethylene cap and a desiccant. Each tube contains 6, 10, or 20 effervescent tablets and are packed in cartons containing 6, 10, 12, 20 or 30 tablets. Not all pack sizes may be marketed. You may sometimes smell a mild sulfur odour when opening the package. This is normal and harmless. Marketing Authorisation Holder: ALTURiX Ltd 287 Upper Fourth Street Milton Keynes MK9 1EH Manufacturer: Elara Pharmaservices Limited 5 Garden Court, Lockington Hall Main Street, Lockington Derby, DE74 2RH United Kingdom
This medicinal product is authorised in the Member States of the EEA under the following names: The Netherlands: Acetylcysteïne Alpex 600 mg, bruistabletten Ireland: NACSYS 600 mg effervescent tablets United Kingdom: NACSYS 600 mg effervescent tablets This leaflet was last revised in November 2024
Frequently asked questions about NACSYS 600mg Effervescent Tablets
How do I take NACSYS 600mg Effervescent Tablets?
NACSYS 600mg Effervescent Tablets comes as tablet containing 600mg. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.
What is the active substance in NACSYS 600mg Effervescent Tablets?
The active substance in NACSYS 600mg Effervescent Tablets is acetylcysteine.
Are there equivalent medicines to NACSYS 600mg Effervescent Tablets?
Medicines with the same active substance, strength and form include: Acepiro 600 mg effervescent tablets. They are interchangeable only if your prescriber or pharmacist says so.
Where does this information come from?
This leaflet reproduces the patient information leaflet approved for NACSYS 600mg Effervescent Tablets, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.
Can I get NACSYS 600mg Effervescent Tablets without a prescription?
Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.
About this leaflet
The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.
- Source: electronic medicines compendium (emc), Datapharm
- Active substance: acetylcysteine
- Official document: view the original leaflet on emc →
⚕For healthcare professionals — Summary of Product Characteristics (SmPC)Full SmPC: dosage, interactions, contraindications, warnings+
4.1. Therapeutic indications
Acetylcysteine is indicated for use as a mucolytic in respiratory disorders such as in bronchitis, emphysema, mucoviscidoses and bronchiectasis. NACSYS 600 mg effervescent tablets is indicated in adults only.
4.2. Posology and method of administration
Posology
Adults
1 effervescent tablet of 600 mg once daily.
Paediatric population
Children older than 2 years of age and adolescents
The safety and efficacy is not established in children aged 2 years and older and adolescents.
Children under 2 years of age
The use of NACSYS 600 mg effervescent tablets is contraindicated in children under 2 years of age (see section 4.3).
Method of administration
Precautions to be taken before handling or administering the medicinal product.
For patients with a reduced cough reflex (elderly and weakened patients) are advised to take the effervescent tablet in the mornings.
Dissolve NACSYS 600 mg effervescent tablets in half a glass of water. This produces a solution that may be consumed immediately.
NACSYS 600 mg effervescent tablets are contraindicated in children under 2 years of age (see section 4.3). Other forms and strengths of Acetylcysteine are more suitable for children >2 and adolescents.
4.3. Contraindications
• Hypersensitivity to acetylcysteine or to any of the excipients listed in section 6.1.
• The tablets should not be used by children under 2 years of age.
4.4. Special warnings and precautions for use
Bronchospasms may occur with the use of acetylcysteine especially in patients with asthma. If bronchospasms occur, the medicinal product should be discontinued immediately.
Caution is advised in patients with a history of peptic ulcer, especially when used concomitantly with other medicinal products known to irritate the mucous membrane of the gastrointestinal tract.
Serious skin reactions such as Stevens-Johnson syndrome and Lyell's syndrome have very rarely been reported in temporal connection with the use of acetylcysteine. In most cases, at least one other suspect medicinal product, which was more likely the cause of the mucocutaneous syndrome could be identified. If cutaneous or mucosal alterations newly occur, immediate medical advice should be sought and the treatment with acetylcysteine should be discontinued immediately.
Bronchial secretions may become more fluid and increase in volume, in particular at the start of the treatment with acetylcysteine. When a patient is unable to cough up the secretions effectively, postural drainage and bronchoaspiration should be performed.
Paediatric population
Mucolytic drugs may obstruct the airways of children under 2 years of age, due to the physiological characteristics of the airways in this age group. The ability to cough up mucus may be limited. Therefore, mucolytic drugs should not be used in children under 2 years of age.
The safety and efficacy is not established in children aged 2 years and older and adolescents.
A mild sulfur odour does not indicate a change in the medicinal product, but is a property of the active substance itself.
Excipients
This medicinal product contains 115 mg sodium per effervescent tablet equivalent to 5.75% of the WHO recommended maximum daily intake of 2g for an adult.
4.5. Interaction with other medicinal products and other forms of interaction
Interaction with other medicinal products
Simultaneous dissolution of NACSYS 600 mg effervescent tablets with other medicinal products is not recommended.
To date, the inactivation of antibiotics by acetylcysteine has been reported only in in-vitro tests, whereby the relevant substances were mixed directly with each other. However, if oral antibiotics are required, it is advised that these should be taken two hours before or after Acetylcysteine.
Acetylcysteine should not be administered concomitantly with antitussive medicinal products.
Acetylcysteine may enhance the vasodilatory effects of nitroglycerin. Caution is advised.
Activated charcoal can decrease the effect of acetylcysteine due to reduced absorption.
Interactions with laboratory tests
Acetylcysteine may have an effect on the values of salicylates by colorimetric analysis.
4.6. Fertility, pregnancy and lactation
Pregnancy
There are limited data about the use of acetylcysteine in pregnant women. Animal studies do not indicate reproductive toxicity (see section 5.3). Acetylcysteine crosses the placenta. Available data do not indicate a risk to the child. If necessary, the use of NACSYS 600 mg effervescent tablets during pregnancy may be considered.
Breast-feeding
It is not known whether acetylcysteine passes into human milk, but at therapeutic doses no effects of acetylcysteine are expected on the infant. NACSYS 600 mg effervescent tablets may be used during breastfeeding.
Fertility
Based on available preclinical experience, there are no indications for possible effects of the use of acetylcysteine on fertility.
4.7. Effects on ability to drive and use machines
There are no data on the effect of acetylcysteine on the ability to drive. An effect is, however, unlikely.
4.8. Undesirable effects
The table below lists the undesirable effects recorded after systemic use of oral acetylcysteine according to system/organ class.
System/organ class
Undesirable effect
Uncommon
(≥1/1,000 to <1/100)
Rare
(≥1/10.000 to <1/1,000)
Very rare
(<1/10,000)
Not known
Immune system disorder
Hypersensitivity*
Anaphylactic shock, anaphylactic/anaphylactoid reactions
Nervous system disorders
Headache
Ear and labyrinth disorders
Tinnitus
Vascular disorders
Haemorrhages
Gastrointestinal disorders
Stomatitis, abdominal pain, nausea, vomiting, diarrhoea
Dyspepsia
Skin and subcutaneous tissue disorders
Facial oedema
General disorders and administration site conditions
Pyrexia
Investigations
Low blood pressure
A decrease in platelet aggregation in the presence of acetylcysteine has been confirmed in various studies. The clinical significance of this has not been determined.
*Hypersensitivity reactions include bronchospasm, dyspnoea, pruritus, urticaria, rash, angioedema and tachycardia.
In patients with a peptic ulcer or peptic ulcer history, acetylcysteine may have an unfavourable effect on the gastric mucosa.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation 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 via Yellow Card Scheme. Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
4.9. Overdose
To date no toxic overdose has been observed for the oral pharmaceutical forms of acetylcysteine.
Voluntary study subjects were treated for three months with a dose of 11.6 acetylcysteine per day without any serious undesirable effects being observed.
Oral doses of up to 500 mg acetylcysteine per kg body weight are tolerated without any signs of poisoning.
Symptoms
Overdoses may lead to gastrointestinal effects such as nausea, vomiting and diarrhoea.
Treatment in the event of an overdose
Symptomatic treatment in the event of an overdose.
💬 Ask about this leaflet
Ask anything about NACSYS 600mg Effervescent Tablets. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.
Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.