Tag: FDA

An ancient belief still common today claims that a cold can be “caught” by prolonged exposure to cold weather such as rain or winter conditions, which is where the disease got its name. Although common colds are seasonal, with more occurring during winter, experiments so far have failed to produce evidence that short-term exposure to cold weather or direct chilling increases susceptibility to infection, implying that the seasonal variation is instead due to a change in behaviors such as increased time spent indoors at close proximity to others. Nevertheless, some studies suggest that lower temperatures of the body of a person can make one more susceptible or prone to infection.

Many herbal and otherwise alternative remedies have been suggested to treat the common cold. However, none of these claims are supported by scientific evidence.

While a number of Chinese herbs and plants have been purported to ease cold symptoms, including ginger, garlic, hyssop, mullein, and others, scientific studies have either not been done or have been found inconclusive.

Echinacea…..
Echinacea flowerEchinacea, also known as coneflowers, is a plant commonly used in herbal preparations for the treatment of the common cold.

A review of sixteen trials of echinacea was done by the Cochrane Collaboration in 2006 and found mixed results. All three trials that looked at prevention were negative. Comparisons of echinacea as treatment found a significant effect in nine trials, a trend in one, and no difference in six trials. The authors state in their conclusion: “Echinacea preparations tested in clinical trials differ greatly. There is some evidence that preparations based on the aerial parts of Echinacea purpurea might be effective for the early treatment of colds in adults but results are not fully consistent. Beneficial effects of other Echinacea preparations, and for preventative purposes might exist but have not been shown in independently replicated, rigorous randomized trials.” A review in 2007 found an overall benefit from echinacea for the common cold.

Although there have been scientific studies evaluating echinacea, its effectiveness has not been convincingly demonstrated. For example, a peer-reviewed clinical study published in the New England Journal of Medicine concluded that “…extracts of E. angustifolia root, either alone or in combination, do not have clinically significant effects on rhinovirus infection or on the clinical illness that results from it.” Recent randomized, double-blind, placebo-controlled studies in adults have not shown a beneficial effect of echinacea on symptom severity or duration of the cold. A structured review of 9 placebo controlled studies suggested that the effectiveness of echinacea in the treatment of colds has not been established. Conversely, two recent meta-analyses of published medical articles concluded that there is some evidence that echinacea may reduce either the duration or severity of the common cold, but results are not fully consistent. However, there have been no large, randomized placebo-controlled clinical studies that definitively demonstrate either prophylaxis or therapeutic effects in adults.[9][10] A randomized, double-blind, placebo-controlled study in 407 children of ages ranging from 2 to 11 years showed that echinacea did not reduce the duration of the cold, nor reduce the severity of the symptoms. Most authoritative sources consider the effect of echinacea on the cold unsupported by evidence.

Vitamin C……Blackcurrants are a good source of vitamin C->
While vitamin C has not been shown to be beneficial in a normal population for the prevention or treatment of the common cold, it might be beneficial in people exposed to periods of severe physical exercise or cold environments.

A well-known supporter of the theory that Vitamin C megadosage prevented infection was physical chemist Linus Pauling, who wrote the bestseller Vitamin C and the Common Cold. A meta-analysis published in 2005 found that “the lack of effect of prophylactic vitamin C supplementation on the incidence of common cold in normal populations throws doubt on the utility of this wide practice”.

A follow-up meta-analysis supported these conclusions:

[Prophylactic use] of vitamin C has no effect on common cold incidence … [but] reduces the duration and severity of common cold symptoms slightly, although the magnitude of the effect was so small its clinical usefulness is doubtful. Therapeutic trials of high doses of vitamin C … starting after the onset of symptoms, showed no consistent effect on either duration or severity of symptoms. … More therapeutic trials are necessary to settle the question, especially in children who have not entered these trials.

Most of the studies showing little or no effect employ doses of ascorbate such as 100 mg to 500 mg per day, considered “small” by vitamin C advocates.[who?] Equally important, the plasma half life of high dose ascorbate above the baseline, controlled by renal resorption, is approximately 30 minutes, which implies that most high dose studies have been methodologically defective and would be expected to show a minimum benefit. Clinical studies of divided dose supplementation, predicted on pharmacological grounds to be effective, have only rarely been reported in the literature.

Zinc preparations…..
A 1999 Cochrane review found the evidence of benefit from zinc in the common cold is inconclusive. A 2003 review however concluded supported 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. Nasally applied zinc gels may lead to loss of smell. The FDA therefore discourages their use.

Zinc acetate and zinc gluconate have been tested as potential treatments for the common cold, in various dosage form including nasal sprays, nasal gels, and lozenges. Some studies have shown some effect of zinc preparations on the duration of the common cold, but conclusions are diverse. About half of studies demonstrate efficacy. Even studies that show clinical effect have not demonstrated the mechanism of action. The studies differ in the salt used, concentration of the salt, dosage form, and formulation, and some suffer from defects in design or methods. For example, there is evidence that the potential efficacy of zinc gluconate lozenges may be affected by other food acids (citric acid, ascorbic acid and glycine) present in the lozenge. Furthermore, interpretation of the results depends on whether concentration of total zinc or ionic zinc is considered.

A recent study showed that zinc acetate lozenges (13.3 mg zinc) shortened the duration and reduced the severity of common colds compared to placebo in a placebo-controlled, double blind clinical trial. Intracellular Adhesion Molecule-1 (ICAM-1) was inhibited by the ionic zinc present in the active lozenges, and the difference was statistically significant between the groups.

There are concerns regarding the safety of long-term use of cold preparations in an estimated 25 million persons who are haemochromatosis heterozygotes. Use of high doses of zinc for more than two weeks may cause copper depletion, which leads to anemia. Other adverse events of high doses of zinc include nausea, vomiting gastrointestinal discomfort, headache, drowsiness, unpleasant taste, taste distortion, abdominal cramping, and diarrhea. Some users of nasal spray applicators containing zinc have reported temporary or permanent loss of sense of smell.

Although widely available and advertised in the United States as dietary supplements or homeopathic treatments, the safety and efficacy of zinc preparations have not been evaluated or approved by the Food and Drug Administration. Authoritative sources consider the effect of zinc preparations on the cold unproven.

Steam inhalation…
Many people believe that steam inhalation reduces symptoms of the cold. However, one double-blind, placebo-controlled, randomized study found no effect of steam inhalation on cold symptoms. A scientific review of medical literature concluded that “there is insufficient evidence to support the use of steam inhalation as a treatment.” There have been reports of children being badly burned when using steam inhalation to alleviate cold symptoms leading to the recommendation to “…start discouraging patients from using this form of home remedy, as there appears to be no significant benefit from steam inhalation.”

Chicken soup…..
In the twelfth century, Moses Maimonides wrote, “Chicken soup…is recommended as an excellent food as well as medication.” Since then, there have been numerous reports in the United States that chicken soup alleviates the symptoms of the common cold. Even usually staid medical journals have published tongue-in-cheek humorous articles on the alleged medicinal properties of chicken soup.

PREVENTION  :
It might seem overwhelming to try to prevent colds, but you can do it. Children average three to eight colds per year.

Here are five proven ways to reduce exposure to germs:-

*Always wash your hands: Children and adults should wash hands at key moments — after nose-wiping, after diapering or toileting, before eating, and before preparing food.

*Disinfect: Clean commonly touched surfaces (sink handles, sleeping mats) with an EPA-approved disinfectant.

*Switch day care: Using a day care where there are six or fewer children dramatically reduces germ contact.

*Use instant hand sanitizers: A little dab will kill 99.99% of germs without any water or towels. The products use alcohol to destroy germs. They are an antiseptic, not an antibiotic, so resistance can’t develop.

*Use paper towels instead of shared cloth towels.

Here are six ways to support the immune system:-

*Avoid secondhand smoke: Keep as far away from secondhand smoke as possible It is responsible for many health problems, including millions of colds.

*Avoid unnecessary antibiotics: The more people use antibiotics, the more likely they are to get sick with longer, more stubborn infections caused by more resistant organisms in the future.

*Breastfeed: Breast milk is known to protect against respiratory tract infections, even years after breastfeeding is done. Kids who don’t breastfeed average five times more ear infections.

*Drink water: Your body needs fluids for the immune system to function properly.

*Eat yogurt: The beneficial bacteria in some active yogurt cultures help prevent colds.

*Get enough sleep: Late bedtimes and poor sleep leave people vulnerable.

Research
Biota Holdings are developing a drug, currently known as BTA798, which targets rhinovirus. The drug has recently completed Phase IIa clinical trials.

ViroPharma and Schering-Plough are developing an antiviral drug, pleconaril, that targets picornaviruses, the viruses that cause the majority of common colds. Pleconaril has been shown to be effective in an oral form. Schering-Plough is developing an intra-nasal formulation that may have fewer adverse effects.

Researchers from University of Maryland, College Park and University of Wisconsin–Madison have mapped the genome for all known virus strains that cause the common cold.

Common Cold Unit
In the United Kingdom, the Common Cold Unit was set up by the Medical Research Council in 1946. The unit worked with volunteers who were infected with various viruses. The rhinovirus was discovered there.  In the late 1950s, researchers were able to grow one of these cold viruses in a tissue culture, as it would not grow in fertilized chicken eggs, the method used for many other viruses. In the 1970s, the CCU demonstrated that treatment with interferon during the incubation phase of rhinovirus infection protects somewhat against the disease, but no practical treatment could be developed. The unit was closed in 1989, two years after it completed research of zinc gluconate lozenges in the prophylaxis and treatment of rhinovirus colds, the only successful treatment in the history of the unit.

Resources :
http://en.wikipedia.org/wiki/Alternative_treatments_used_for_the_common_cold#Zinc_preparations
http://www.nlm.nih.gov/medlineplus/ency/article/000678.htm
http://en.wikipedia.org/wiki/Common_cold

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