ATC Group: R05C Expectorants, excl. combinations with cough suppressants

Acetylcysteine is N-acetyl derivative of cysteine. Used as a mucolytic agent to reduce the viscosity of mucous secretions.

Ambroxol induces activation of the surfactant system by acting directly on the type II pneumocytes of the alveoles and the Clara cells in the region of the small airways. It promotes the formation and outward transfer of surface-active material in the alveolar and bronchial region of the foetal and adult lungs.

Bromhexine is an expectorant used in the treatment of respiratory disorders associated with viscid or excessive mucus. Bromhexine is a synthetic derivative of the herbal active ingredient vasicine. It has been shown to increase the proportion of serous bronchial secretion, making it more easily expectorated. It is indicated as “secretolytic therapy in bronchopulmonary diseases associated with abnormal mucus secretion and impaired mucus transport”.

Carbocisteine (5-carboxymethyl L-cysteine) has been shown in normal and bronchitic animal models to affect the nature and amount of mucus glycoprotein that is secreted by the respiratory tract. An increase in the acid:neutral glycoprotein ratio of the mucus and a transformation of serous cells to mucus cells is known to be the initial response to irritation and will normally be followed by hypersecretion.

Recombinant human DNase is a genetically engineered version of a naturally occurring human enzyme which cleaves extracellular DNA. In vitro, dornase alfa hydrolyses DNA in sputum and greatly reduces the viscoelasticity of cystic fibrosis sputum.

Erdosteine is a mucolytic agent reducing the viscosity of mucus and purulent sputum. Erdosteine is a prodrug, becoming active after metabolism whereby free thiol groups are formed.

Guaifenesin is an expectorant the action of which promotes or facilitates the removal of secretions from the respiratory tract. The precise mechanism of action of guaifenesin is not known; however, it is thought to act as an expectorant by increasing the volume and reducing the viscosity of secretions in the trachea and bronchi. In turn, this may increase the efficiency of the cough reflex and facilitate removal of the secretions. Guaifenesin is over-the-counter drug for the treatment of cough and common cold.

Ipecacuanha root extract has been widely used in syrup form as a potent and effective emetic. Ipecacuanha powder had been used to induce sweating at the onset of influenza, and small amounts of the extract have been incorporated into cough syrups as expectorants.

Mesna is an antidote, and offers the possibility of reliably preventing urotoxic side-effects associated with aggressive cancer chemotherapy using oxazaphosphorine cytostatics.

Potassium iodide is indicated as a thyroid-blocking agent to prevent the uptake of radioactive iodine, for example after a nuclear accident or during a nuclear medicine investigation before administering a radioiodinated compound, which is metabolised to iodide or which contains radioiodine impurities.

Sobrerol is a mucolytic known due its emplyment in therapy for respiratory diseases. In preclinical studies sobrerol, administered daily at the oral dose of 400 mg/rat, markedly decreased the monocrotaline-induced alterations and regulate the development of pulmonary hypertension. Treatment with sobrerol was well tolerated and significantly reduced frontal headache and rhinorrhoea, efficacy being confirmed by rhinomanometry.