Cough medicine



  A cough medicine is a medicinal drug used to treat coughing and related conditions. Dry coughs are treated with cough suppressants (antitussives) that suppress the body's urge to cough, while productive coughs (coughs that produce phlegm) are treated with expectorants that loosen mucus from the respiratory tract. These medicines are widely available in the form of cough syrup, also known as linctus.

Contents

Cough suppressants

Cough suppressants may act centrally (on the brain, and specifically the vagus nerve) or locally (on the respiratory tract) to suppress the cough reflex.

Centrally acting suppressants include codeine. Dextromethorphan can interact with antidepressants to cause [(serotonin syndrome)].

Peripherally acting substances include menthol) in vapor-steam products and it is effective as a cough suppressant. Although it is commonly claimed that liquid cough medicines must coat the throat to be effective, there is no evidence that it is possible to control coughing by this means.

One might think it unwise to suppress the cough reflex (the mechanism for expelling mucus from the respiratory tract) but severe coughing may lead to lung irritation, causing a vicious cycle. The cough reflex is also very strong and cannot be completely suppressed. However, a dry cough (without mucus production) or a cough that is exhausting and prevents sleep could be treated with suppressants. A productive cough should not be suppressed.

Recent studies have found that side effects in the blind tests.[2]

Expectorants

An expectorant (from Latin ex- "out" + pectoris "of the chest") is a medicine or herb which increases the expulsion of tracheal or bronchial mucus through expectoration or coughing. Expectorants are used to decrease the viscosity of tenacious mucus, or to increase the secretion of mucus in dry irritant unproductive cough, thereby, lubricating the air passages and making coughing more productive.[3] over-the-counter preparations, and is commonly combined with other medications designed to relieve various cold-related symptoms (including cough suppressants, decongestants, antihistamines and pain relievers/fever reducers).

Cough drops

Main article: Throat lozenge

Cough drops or throat lozenges are tablets which people can suck to soothe the throat or to alleviate excessive coughing. They are usually small, sweetened (often with artificial sweeteners), and contain an oral anesthetic, such as Strepsils and Luden's.

Controversy

In 2002, researchers at the University of Bristol (Schroeder & Fahey) published a study in the British Medical Journal indicating that some cough medicines are no more effective than placebos for acute coughs in adults, including coughs related to upper respiratory tract infections.[4] In 2006, the American College of Chest Physicians published a guideline that had the dual message that many over-the-counter cough medicines are not effective and that those that are effective in treating the symptom do not treat the underlying cause; the underlying disorder emphasized by the guideline was pertussis (whooping cough) in the elderly.[5]

Many cough mixtures contain both an expectorant and a suppressant, even though an expectorant requires the action of a cough to expel mucus.

Mass poisonings due to diethylene glycol

According to the New York Times, at least eight mass poisonings have occurred as a result of counterfeit cough syrup, mostly if not totally produced in China, substituting inexpensive glycerin. Recently, 365 deaths were reported in Panama, which were associated with cough syrup laced with diethylene glycol. [6]

Colloquial usage

"Cough medicine", for example "Grandpa's old cough medicine", is also a commonly used euphemism for whiskey and other strong alcoholic beverages, or even actual cough medicine such as NyQuil which in some formulations has a high alcohol content. Rock candy dissolved in whiskey was once a common home-made cough medicine.

Botanical sources

See also

  • Purple drank

References

  1. ^ http://www.hersheys.com/nutrition/theobromine.asp
  2. ^ Vince, Gaia. "Persistent coughs melt away with chocolate", New Scientist, November 22 2004. 
  3. ^ Saponin Glycosides, by Georges-Louis Friedli, URL accessed Dec 2007.
  4. ^ Knut Schroeder and Tom Fahey (2002). "Systematic review of randomised controlled trials of over the counter cough medicines for acute cough in adults". British Medical Journal 324: 329–331. PMID 11834560.
  5. ^ American College of Chest Physicians (January 9 2006). "New Cough Guidelines Urge Adult Whooping Cough Vaccine; Many OTC Medications Not Recommended for Cough Treatment". Press release.
  6. ^ http://www.nytimes.com/2007/05/06/world/06poison.html
  7. ^ Hoffmann, David (March, 1988). The Complete Illustrated Holistic Herbal, Rev Ed, Element Books. ISBN 978-1852300241. 
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Cough_medicine". A list of authors is available in Wikipedia.