ACETYLCYSTEINE

ACETYLCYSTEINE

100mg Granules for Solution

200mg Granules for Solution

600mg Effervescent Tablet

DRUG CATEGORY: Mucolytic

Pharmacology:

Acetylcysteine exerts an intensive mucolytic-fluidifying action on mucous and mucopurulent secretions by depolymerizing the mucoproteic complexes and the nucleic acids which confer viscosity to the vetreous and purulent component of the sputum and other sections.

Furthermore, acetylcysteine exerts a direct antioxidant action, having a free thiol (-SH) nucleophilic group which is able to interact directly with electrophilic group of the oxidant radicals. Of particular interest is the recent finding that acetylcysteine protects α1-antitrypsin enzyme inhibiting elastase from the inactivation by hypochlorous acid (HOCl), a powerful oxidant agent produced b the myeloperoxidase enzyme of activated phagocytes.

These features make acetylcysteine particularly suitable for the treatment of acute and chronic affections of the respiratory system, characterized by thick, viscous mucous and mucopurulent secretions.

In addition, due to its molecular structure, acetylcysteine can easily cress the cellular membranes. Inside the cell, acetylcysteine can easily cross the cellular membranes. Inside the cell, acetylcysteine is deacetylated to L-cysteine, an amino acid indispensable for the glutathione synthesis (GSH).

Glutathione (GSH) is a highly reactive tripeptide found ubiquitously in the various tissues of animal and is essential for the maintenance of functional capacity as will as cellular morphological integrity. It represents the most important protective endocellular mechanism against oxidant radicals, either of external or internal nature, as well as toward numerous cytotoxic substances.

Acetylcysteine plays a role of primary importance in the maintenance of adequate GSH levels contributing to the cellular protection from harmful agents which, through progressive GSH depletion, would be able to express their cytotoxic action as in the case of paracetamol poisoning.

Due to this mechanism of action, acetylcysteine is also indicated as a specific antidote in paracetamol poisoning and in the course of treatment of cyclophosphamide-induced hemorrhagic cystitis, in the latter case, it provides the -SH groups necessary to inactivate acrolein, a toxic metabolite that affects the urinary mucosae, whilst interfering with chemotherapy.

Indication:

Treatment of respiratory affections characterized by thick and viscous hypersecretions due to acute bronchitis, chronic bronchitis and its exacerbation, pulmonary emphysema, mucoviscidosis and bronchiectasis.

Contraindication:

Known hypersensitivity to acetylcysteine. Its granules and tablets are contraindicated in patients suffering from phenylketonuria due to the aspartame content.

Children below 2 years of age.

Dosage and administration:

Adults:

1 sachet of acetylcysteine 200mg or 2 sachets of acetylcysteine 100mg 2-3 times a day

1 acetylcysteine 600mg effervescent tablet daily (preferably in the evening)

For the prevention of exacerbation, the use of acetylcysteine 200mg sachet is recommended.

Children:

1 sachet of acetylcysteine 100mg, 2 to 4 times a day, according to age

The duration of treatment should be 5 to 10days in the acute phase. It may be continued in the chronic state for several months according to the advice of the physician.

Acetylcysteine is contraindicated in children below 2 years of age.

Modality of Use

Dissolve the tablets or granules in a glass containing a small quantity of water. Mix if necessary, with a spoon. The solution can be drunk directly from the glass or in the case of children, it may be given with the use of a teaspoon or in a feeding bottle.

Special Warnings and Precautions for Use

Patients suffering from bronchial asthma must be strictly monitored during the therapy. Should bronchospasm occur, the treatment must be suspended immediately. It should be used with caution in asthmatic patients and patients with a history of peptic ulceration. The possible presence of sulfurous smell is not indicative of product alterations but is a characteristic of the active ingredient contained in this preparation. It is preferred not to mix other drugs with acetylcysteine solution.

Mucolytic agents can induce respiratory obstruction in children under 2 years of age. Due to the physiological characteristics of the airways in this age group, the ability to expectorate may be limited. Therefore, mucolytic agents should not be use in children 2 years of age. (See contraindications).

Acetylcysteine granules contain sorbitol. Patients with rate hereditary problems of fructose intolerance should not take this medicine. Acetylcysteine effervescent table contains 6.8mmol (or 156.9mg) sodium per dose. This must be taken into consideration by patients on a controlled sodium diet.

Use During Pregnancy and Lactation

Pregnancy

There is limited clinical data relating to women exposed to acetylcysteine during pregnancy. Animals studies do not suggest any direct or indirect harmful effects on the pregnancy, embryo/fetal development, birth or postnatal development.

Lactation

There is no available information on the excretion in breast milk. The product should only be used during pregnancy and lactation after the benefit/risks have been weighed up carefully.

Drug Interactions

Drug interaction studies have been performed only in adults. Antitussive drugs and acetylcysteine should not be concurrently administered because the reduction in cough reflex could lead to accumulation of bronchial secretions.

Concurrent administration of nitroglycerin and acetylcysteine has been shown to cause significant hypotension and enhance temporal artery dilation. If concurrent nitroglycerin and acetylcysteine therapy is necessary, patients should be monitored for hypotension, which can be severe, and warned of the possibility of headaches.

Acetylcysteine may interfere with colorimetric assay method for salicylate measurement. Acetylcysteine may interfere with urine ketone test.

Activated charcoal may reduce the effect of acetylcysteine. Dissolution of acetylcysteine formulation concomitantly with other drugs is not recommended. Reports of an inactivation of antibiotics resulting from acetylcysteine so far only related to in-vitro tests in which the relevant substances were mixed directly. Nevertheless, when other oral drugs or antibiotics are required, it is advisable to administer the drugs 2 hours apart from acetylcysteine.

Adverse Effects:

The oral intake of the product may occasionally be followed by nausea and vomiting and rarely, by hypersensitivity reactions such as urticaria and bronchospasm.

Immune System Disorders

Hypersensitivity

Anaphylactic shock (Very rare)

Nervous System Disorders

Headache

Ear and Labyrinth Disorder

Tinnitus

Cardiac Disorders

Tachycardia

Vascular Disorders

Hemorrhage (Very rare)

Respiratory, thoracic and Mediastinal Disorders

Bronchospasm (rare)

Dyspnea (rare)

Gastrointestinal Disorders

Vomiting

Diarrhea

Stomatitis

Abdominal pain

Nausea

Dyspepsia (rare)

Skin and Subcutaneous Tissue Disorders

Urticaria

Rash

Angioedema

Pruritus

General Disorders and Administration Site Conditions

Pyrexia

Face edema (unknown)

Investigations

Blood pressure decreased

In very rare cases, the occurrence of severe skin reactions such as Stevens-Johnson syndrome and Lyell's syndrome has been reported in temporal connection with the administration of acetylcysteine. In most cases, at least one co-suspect drug, more probably involved in triggering the report mucocutaneous syndrome could be identified.

Seek immediate medical advice if any new changes to the skin or mucous membrane occur. Acetylcysteine must be stopped immediately.

A decrease in platelet aggregation in the presence of acetylcysteine has been confirmed by various investigations. The clinical significance has not yet been established.

Overdose:

For oral pharmaceutical forms of acetylcysteine, no case of overdose has been reported to date. Healthy volunteers received 11.6g of acetylcysteine daily for three months without any serious undesirable effects. Oral doses of up to 500mgNAC/kg body-weight was tolerated without any symptoms of poisoning.

Symptoms

Overdose may lead to gastrointestinal symptoms such as nausea, vomiting and diarrhea.

Treatment

There in no specific antidote for acetylcysteine and treatment is symptomatic.

Effects on the Ability to Drive and Use Machines:

Acetylcysteine has no known influence on the ability to drive and use machines.

Storage:

Store at temperatures not exceeding 25^oC.