Cold medicines are a group of
medications taken individually or in
combination as a
treatment for the symptoms of the
common cold and similar conditions of the upper respiratory tract. The term encompasses a broad array of drugs, including
analgesics,
antihistamines and
decongestants, among many others. It also includes drugs which are marketed as cough suppressants or antitussives, but their effectiveness in reducing cough symptoms is unclear or minimal.[1][2][3]
While they have been used by 10% of American children in any given week, they are not recommended in Canada or the United States in children six years or younger because of lack of evidence showing effect and concerns of harm.[4][5]
Types
There are a number of different cough and cold medications, which may be used for various coughing symptoms. The commercially available products may include various combinations of any one or more of the following types of substances:[citation needed]
Mucokinetics, or mucolytics, are a class of drugs which aid in the clearance of mucus from the airways, lungs, bronchi, and trachea. Examples are
carbocisteine,
ambroxol, and
bromhexine.
Expectorants are substances claimed to make coughing easier while enhancing the production of mucus and phlegm. Two examples are
acetylcysteine and
guaifenesin.
The efficacy of cough medication is questionable, particularly in children.[6][3] A 2014
Cochrane review concluded that "There is no good evidence for or against the effectiveness of OTC medicines in acute cough".[1] Some cough medicines may be no more effective than
placebos for acute coughs in adults, including coughs related to upper respiratory tract infections.[7] The
American College of Chest Physicians emphasizes that cough medicines are not designed to treat
whooping cough, a cough that is caused by bacteria and can last for months.[8] No over-the-counter cough medicines have been found to be effective in cases of
pneumonia.[9] They are not recommended in those who have
COPD,
chronic bronchitis, or the
common cold.[10][2] There is not enough evidence to make recommendations for those who have a cough in
cancer.[11]
Medications
Dextromethorphan (DXM) may be modestly effective in decreasing cough in adults with viral upper respiratory infections. However, in children, it has not been found to be effective.[12]
Codeine was once viewed as the "gold standard" in cough suppressants, but this position is now questioned.[13] Some
placebo-controlled trials have found that it is ineffective against some forms of cough, including acute cough in children.[14][15] It is thus not recommended for children.[15][16] Additionally, there is no evidence that
hydrocodone is useful in children.[17] Similarly, a 2012 Dutch guideline does not recommend its use to treat acute cough.[18]
A number of other commercially available cough treatments have not been shown to be effective in viral upper respiratory infections. These include for adults:
antihistamines, antihistamine-decongestant combinations,
benzonatate, anti asthmatic-expectorant-mucolytic combinations, expectorant-bronchodilator combinations, leukotriene inhibitors,
ambroxol, and
guaifenesin, sometimes with analgesics, antipyretics, anti inflammatories, and anticholinergics; and for children: antihistamines,
decongestants for clearing the nose, or combinations of these and leukotriene inhibitors for allergy and asthma.[12][failed verification] However,
antihistamines cannot be used as an
empirical therapy in case of chronic, or non-specific cough, especially in very young children.[19] Long term diphenhydramine use is associated with negative outcomes in older people.[20]
Alternative medicine
A small study found
honey may be a minimally effective cough treatment due to "well-established antioxidant and antimicrobial effects" and a tendency to soothe irritated tissue.[21] A
Cochrane review found there was weak evidence to recommend for or against the use of honey in children as a cough remedy.[22] In light of these findings, the Cochrane study they found honey was better than no treatment, placebo, or diphenhydramine but not better than dextromethorphan for relieving cough symptoms.[22] Honey's use as a cough treatment has been linked on several occasions to infantile
botulism and accordingly should not be used in children less than one year old.[23]
Many
alternative treatments are used to treat the
common cold, though data on effectiveness is generally limited. A 2007 review states that, "alternative therapies (i.e.,
Echinacea,
vitamin C, and
zinc) are not recommended for treating common cold symptoms; however,...Vitamin C prophylaxis may modestly reduce the duration and severity of the common cold in the general population and may reduce the incidence of the illness in persons exposed to physical and environmental stresses."[24] A 2014 review also found insufficient evidence for Echinacea, where no clinical relevance was proven to provide benefit for treating the common cold, despite a weak benefit for positive trends.[25] Similarly, a 2014 systematic review showed that garlic may prevent occurrences of the common cold but there was insufficient evidence of garlic in treating the common cold and studies reported adverse effects of a rash and odour.[26] Therefore, more research needs to be done to prove that the benefits outweigh the harms.
A 2009 review found that the evidence supporting the effectiveness of zinc is mixed with respect to cough,[12] and a 2011 Cochrane review concluded that zinc "administered within 24 hours of onset of symptoms reduces the duration and severity of the common cold in healthy people".[27] A 2003 review concluded: "Clinical trial data support the value of zinc in reducing the duration and severity of symptoms of the common cold when administered within 24 hours of the onset of common cold symptoms."[28] Zinc gel in the nose may lead to long-term or permanent loss of smell. The FDA therefore discourages its use.[29]
Cough medicines, especially those containing dextromethorphan and
codeine, are often abused as
recreational drugs.[30][31] Abuse may result in hallucinations, loss of consciousness and death. Many cough syrups can contain acetaminophen which will cause liver damage in recreational users. [31]
Adverse effects
A number of accidental overdoses and well-documented adverse effects suggested caution in children.[23] The FDA in 2015 warned that the use of codeine-containing cough medication in children may cause breathing problems.[32] Cold syrup overdose has been linked to visual and auditory hallucinations as well as rapid involuntary jaw, tongue, and eye movements in children.[medical citation needed]
Decongestants are possibly harmful to people with high blood pressure or a heart disease because these substances can constrict the blood vessels.[33]
History
Heroin was originally marketed as a cough suppressant in 1898.[34] It was, at the time, believed to be a non-addictive alternative to other opiate-containing cough syrups. This was quickly realized not to be true as heroin readily breaks down into morphine in the body. Morphine was already known to be addictive.[citation needed]
Sudafed is a brand manufactured by
McNeil Laboratories.[citation needed] The original
formulation contains the active ingredient
pseudoephedrine, but formulations without pseudoephedrine are also being sold under the brand.[citation needed] In 2016, it was one of the biggest selling branded over-the-counter medications sold in Great Britain, with sales of £34.4 million.[37] The effectiveness of phenylephrine by mouth as a nasal decongestant is questionable.[38]
Gee's Linctus is a cough medicine which contains
opium tincture.[39] New Zealand in 2019 moved it to prescription only.[40]
Codral is a brand name manufactured by
Johnson & Johnson and sold primarily in Australia and New Zealand. Codral is the highest-selling cold and flu medication in Australia.[41]
Economics
In the United States, several billion dollars are spent on over-the-counter products per year.[42]
According to The New York Times, at least eight mass poisonings have occurred as a result of counterfeit cough syrup in which
medical-gradeglycerin has been replaced with
diethylene glycol, an inexpensive, yet toxic, glycerin substitute marketed for industrial use. In May 2007, 365 deaths were reported in
Panama, which were associated with cough syrup containing diethylene glycol.[43] In 2022, the deaths of 66 children in
The Gambia were linked to four pediatric cough syrup medications that contained
diethylene glycol and
ethylene glycol.[44][45]
In 2022, the US
Food and Drug Administration issued a warning against cooking foods in cough syrup after a video of someone preparing "NyQuil chicken", sometimes also called "sleepy chicken", became popular on social media. Cough syrup is designed to be stored at room temperature and its properties can change when it is heated, making it potentially deadly. Heated cough syrup can also vaporize, leading to inhalation hazards.[46][47][48] The warning received attention from many news outlets, but some criticized the FDA's handling of the issue for amplifying the attention the topic received online and questioned if making and eating NyQuil chicken actually existed as a widespread trend.[49][50][51]
^Reeves, Roy R.; Ladner, Mark E.; Perry, Candace L.; Burke, Randy S.; Laizer, Janet T. (March 2015). "Abuse of Medications That Theoretically Are Without Abuse Potential". Southern Medical Journal. 108 (3): 151–157.
doi:
10.14423/SMJ.0000000000000256.
ISSN1541-8243.
PMID25772048.
S2CID42989013.
^Burch, Druin (2009). Taking the Medicine: A Short History of Medicine's Beautiful Idea, and Our Difficulty Swallowing It. Random House. p. 118.
ISBN9781407021225.