The effects of traditional over-the-counter cold medicines in your body are focused on the alleviation of the cold symptoms, and not the treatment of the cold itself.
Common symptoms of the common cold are fever, sneezing, headache, nasal discharge, and nasal congestion. Over-the-counter medicines to address these cold symptoms are antihistamines, decongestants, cough suppressants and expectorants, as these are the symptoms of the common cold.
Antihistamines affect the body by drying out the mucus membrane. Thus, they are helpful in alleviating symptoms of rhinorrhea or runny nose, sneezing, and reducing the amount of nasal mucous. They are not however, beneficial in treating symptoms of nasal obstruction.
On the other hand, nasal decongestants were found to be helpful in relieving nasal obstruction.
Combination antihistamine and decongestant medicines were found to benefit both symptoms of rhinorrhea and nasal obstruction.
Despite the benefits of cold medicines on your body when taken upon the onset of a common cold virus on your body, the use of cold medicines to treat the common cold has been controversial in medical circles because of its alleged harmful side effects on the body.
According to a study conducted by Dr. Simasek and Dr. Blandino of the University of Pittsburgh Medical Center, antihistamines can affect your body by making you susceptible to arrhythmia, blurred vision, hallucinations, paradoxic excitability, sedation, and urinary retention. On the other hand, decongestants can cause agitation, anorexia, hypertension, seizures, nausea, and palpitations. Thus, the use of cold medicines must be in moderation, with their benefits weighed against their side effects.
It is because of these side effects that the taking of cold medications are advised against for young children, especially because they have not been shown to alleviate cold symptoms in children in the way that that they have helped treat cold symptoms in adults.
“Treatment of the Common Cold.” American Academy of Family Physicians. 15 Feb. 2007. Web. 03 Oct. 2010. http://www.aafp.org/afp/2007/0215/p515.html.
Smith, MBH, and W. Feldman. “Over-the-Counter Cold Medications: A Critical Review of Clinical Trials Between 1950 and 1991.”Clinical Pediatrics 34.11 (1995): 616-17. Print.
Carr, Brandon C. “Efficacy, Abuse, and Toxicity of Over-the-Counter Cough and Cold Medicines in Pediatric Population.” Current Opinion in Pediatrics 18.2 (2006): 184-88. Lippincott Williams & Wilkins. Web. 3 Oct. 2010. http://journals.lww.com/co-pediatrics/Abstract/2006/04000/Efficacy,_abuse,_and_toxicity_of_over_the_counter.18.aspx