Some placebo-controlled trials have found that it is ineffective against some forms of cough, including acute cough in children. It is thus not recommended for children. Additionally, there is no evidence that hydrocodone is useful in children. Similarly, a 2012 Dutch guideline does not recommend its use to treat acute cough. 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. However, antihistamines cannot be used as an empirical therapy in case of chronic, or non-specific cough, especially in very young children. Long term diphenhydramine use is associated with negative outcomes in older people. 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. A Cochrane review found there was weak evidence to recommend for or against the use of honey in children as a cough remedy. 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.
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." Zinc gel in the nose may lead to long-term or permanent loss of smell. The FDA therefore discourages its use. Recreational usage
Cough medicines, especially those containing dextromethorphan and codeine, are often abused as recreational drugs. Abuse may result in hallucinations, loss of consciousness and death. Adverse effects
A number of accidental overdoses and well-documented adverse effects suggested caution in children. The FDA in 2015 warned that the use of codeine-containing cough medication in children may cause breathing problems. Cold syrup overdose has been linked to visual and auditory hallucinations as well as rapid involuntary jaw, tongue, and eye movements in children. History
Heroin was originally marketed as a cough suppressant in 1898. 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. Society and culture
Brands
Some brand names include: Benilyn, Sudafed, Robitussin and Vicks among others. Most contain a number of active ingredients.Sudafed is a brand manufactured by McNeil Laboratories. The original formulation contains the active ingredient pseudoephedrine, but formulations without pseudoephedrine are also being sold under the brand. In 2016, it was one of the biggest selling branded over-the-counter medications sold in Great Britain, with sales of £34.4 million.