Expectorants and Mucolytics

Aromatic agents such as eucalyptus and menthol have decongestant effects in the nose and can be useful in short-term relief of cough. Menthol inhibits capsaicin-induced cough in normal volunteers (Morice et al. 1994), and acts on a 

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The expectorants and mucolytics are contraindicated in patients with known hypersensitivity. The expectorant potassium iodide is contraindicated during pregnancy (Pregnancy Category D). 

A molecular dissection of the alkaloid vasicine (52) ultimately resulted in the expectorant and mucolytic agent bromhexine (54). The synthesis starts with displacement of halogen on 2-nitrobenzyl-bromide (53) by N-methyl cyclohexylamine, followed by Raney nickel and hydrazine reduction of the nitro group. Bromination in acetic acid then affords bromhexine. 

Certain alkaloids such as vasicine obtained from plant Adhatoda vasica act as potent expectorant and mucolytic agent. Bromhexine, a derivative of vasicine depolymerises mucopolysaccharides directly and by liberating lysosomal enzymes. Another compound acetylcysteine opens disulfide bonds in mucoproteins present in sputum and decrease its viscosity. Carbocisteine acts in same manner. 

Viral pneumonia is treated symptomatically with bronchodilators, antipyretics, analgesics, expectorants and mucolytics, and cough suppressants. 

Expectorants Expectorants, called mucolytics, liquefy and loosen viscous mucous secretions so the secretions can be removed by coughing. 

Mucolytics reduce the viscosity of tenacious and purulent mucus, thus faciUtating removal. The distinction between mucolytics and other classes of expectorants is frequently blurred. Steam, sometimes in conjunction with surfactants or volatile oils, has long been used to decrease viscosity by physical hydration. However, agents that chemically depolymerize certain components of mucus are available. Trypsin and other proteolytic enzymes have shown good clinical activity because of their abiUty to cleave glycoproteins. Pancreatic domase, which depolymerizes DNA found in purulent mucus, also has shown clinical utihty. 

Discuss important preadministration and ongoing assessment activities the nurse should perform on patients receiving an antitussive, mucolytic, or expectorant drug. 

LJpper respiratory infections are among die most common afflictions of humans. The drug used to treat die discomfort associated widi an upper respiratory infection include antitussives, mucolytics, and expectorants. Many of tiiese dm are available as nonprescription (over-die-counter) dni, whereas otiiers are available only by prescription. 

Use of codeine may result in respiratory depression, euphoria, light-headedness, sedation, nausea, vomiting, and hypersensitivity reactions. The more common adverse reactions associated with the antitussives are listed in the Summary Drug Table Antitussive, Mucolytic, and Expectorant Drugs. When used as directed, nonprescription cough medicines containing two or more ingredients have few adverse reactions. However, those that contain an antihistamine may cause drowsiness. 

The more common adverse reactions associated with mucolytic and expectorant dm are listed in die Summary Drug Table Antitussive, Mucolytic, and Expectorant Dru i. 

Unit V has three chapters concerning drugs that affect the respiratory system. The first chapter in this unit discusses antihistamines and decongestants, the second chapter in the unit covers bronchodilators and antiasthma drugs, and the last chapter of the unit deals with antitussives, mucolytics, and expectorants. 

Mucous airway obstruction. Mu-colytics, such as acetylcysteine, split disulfide bonds in mucus, hence reduce its viscosity and promote clearing of bronchial mucus. Other expectorants (e.g., hot beverages, potassium iodide, and ipecac) stimulate production of watery mucus. Acetylcysteine is indicated in cystic fibrosis patients and inhaled as an aerosol. Whether mucolytics are indicated in the common cold and whether expectorants like bromohexine or am-broxole effectively lower viscosity of bronchial secretions may be questioned. 

Q9 Mucolytic drugs may be useful. These agents facilitate expectoration by reducing the viscosity of sputum. They break bonds in the glycoproteins contained in mucus, so liquefying the secretion and promoting easier removal from the lung. 

Every formulary is replete with combinations of antitussives, expectorants, mucolytics, broncho-dilators and sedatives. Although choice is not critical, a knowledge of the active ingredients is important, for some contain sedative anti-muscarinic antihistamines or phen)rpropanolamines (which may antagonise antihypertensives). Use of... 

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