"The new treatment is based on delivering a double blow to the cold illness," said principal investigator and the study's lead author Dr. Jack M. Gwaltney, Jr., chairman, Division of Epidemiology and Virology in the Department of Internal Medicine at U.Va. "One part of the treatment knocks out the virus which causes the infection, and the second part blocks the body's response to the infection, which is the cause of cold symptoms."
Research on what causes cold symptoms has been pioneered at U.Va. by Gwaltney, Dr. J. Owen Hendley and Dr. Birgit Winther, who are co-investigators of the new study. Their findings over the last two decades challenge the belief that cold symptoms are the result of the damage that a cold virus does to the lining of the nose. Instead, the U.Va. researchers found that virus damage to the nasal lining is minimal, and the symptoms of a cold are due to the body's inflammatory response to the infection. In recent years, they and other investigators have identified a number of inflammatory pathways associated with cold symptoms:
Stuffy nose results from dilation of blood vessels in certain tissues in the nose called turbinates. When the blood vessels dilate, turbinates swell and block air passages, making breathing through the nose difficult. Certain natural inflammatory substances in the body, such as histamine and kinin, are released during cold virus infection, causing nasal blood vessels to dilate.Runny nose results from two different inflammatory events, nasal mucus gland secretion and leakage of fluid from nasal blood vessels. Nasal mucus gland secretion is triggered by the nervous system's response to cold virus infection. Fluid leakage from nasal blood vessels results from the action of histamine and kinin.
Sneezing results from a reflex that originates in the nose, passes through the brain and activates the diaphragm and muscles in the chest. Antihistamine treatment blocks sneezing associated with colds, suggesting that histamine has a role in causing this symptom.
Sore throat occurs when pain nerves in the throat are stimulated. Kinin, a potent stimulator of pain nerves, is released during colds.
Cough results from another reflex that can be triggered by an inflammatory mediator produced in the body called prostaglandin.
General cold symptoms, such as headache and not feeling well, are associated with interleukin, another inflammatory mediator.
The U.Va. clinical study was based on this new understanding of what causes cold symptoms. One ingredient of the treatment was the antiviral drug interferon, which attacks the virus infection itself. Interferon is a natural protein of the body that makes cells resistant to cold virus infection for up to 24 hours. In the new treatment, three doses of interferon were given intranasally at 12-hour intervals.
The other two treatment ingredients treated the inflammatory pathways that cause cold symptoms. Chlorpheniramine is an antihistamine and anticholinergic, which blocks sneezing and runny nose. The other ingredient, ibuprofen, reduces sore throat, coughing and headache, because it -- like other non-steroidal anti-inflammatory drugs -- blocks the action of prostaglandin. Treatment with these drugs also reduces coughing.
In the U.Va. study, the chlorpheniramine and ibuprofen were given orally at 12-hour intervals for the duration of the illness. Treatment with all three ingredients started in the early stage of the cold.
The researchers tested the treatment in a double blind, placebo-controlled clinical trial in 150 young male and female adults. During the five days of the study, the daily average total symptoms score of volunteers receiving the actual drugs were reduced by 33 percent to 73 percent compared to those on non-active placebo treatment. Volunteers who received the actual drugs experienced reduced severity of sneezing, runny nose, nasal obstruction, sore throat, cough and headache. They also had less nasal mucus production, nasal tissue use and virus concentration in nasal secretions.
The study showed that adding interferon to the treatment made it more effective than chlorpheniramine and ibuprofen alone. The side effects associated with the treatment were drowsiness, which occurred in 9 percent of volunteers on chlorpheniramine, and none of those on placebo. Mild blood-tinged nasal mucus occurred in 19 percent of subjects on interferon and 10 percent of the subjects on placebo. No side effects led to discontinuation of treatment.
"The new method for treating colds is more effective than symptomatic cold treatments or antiviral treatment used alone," Gwaltney said.
The study was funded by U.Va. and the new treatment is licensed to Coldcure, Inc., in Richmond for development into commercial use.
Journal
The Journal of Infectious Diseases