PHOENIX -- New research confirms the efficacy of zincum gluconicum nasal gel in reducing the severity and duration of common cold symptoms when treatment is started as late as the second day of illness. The study, which appears in the January issue of QJM: An International Journal of Medicine, was the first trial on the naturally acquired common cold to extend initiation of treatment beyond the first 24 hours of illness.
"All previous evaluations of zincum gluconicum nasal gel's effect on the naturally acquired common cold limited initiation of treatment to the first 24 hours of symptoms," explained Sherif B. Mossad, MD, FACP, FIDSA, Department of Infectious Diseases, Cleveland Clinic Foundation. "We now have findings to document a significant reduction in severity and duration of symptoms even when treatment is started as late as 48 hours after onset of illness."
Mossad said his study adds to a growing body of evidence supporting the effectiveness of zincum gluconicum nasal gel in reducing nasal drainage, nasal congestion, sore throat, and other symptoms typical of virus-induced rhinitis. However, he noted that his study is the first to include microbiological confirmation of rhinovirus infection with polymerase chain reaction as well as information related to the specific time of perceived improvement of individual symptoms.
"Among the subset of patients with confirmed rhinovirus infection, the zinc nasal gel-treated patients experienced a 50 percent reduction in time to cold resolution when compared to the placebo group," said Mossad.
"This is great news for busy cold sufferers who cannot always treat their illness during that initial 24-hour period," said Carl J. Johnson, president and chief executive officer of Matrixx Initiatives, Inc., the makers of Zicam cold remedy zinc nasal gel products. "It's encouraging to see the building body of scientific evidence that supports the efficacy of using zinc nasal gel to combat the common cold."
The randomized, double-blind, placebo-controlled study was supported by an unrestricted grant from Matrixx Initiatives, Inc. The population included 78 patients, between the ages of 18 and 55, who had cold symptoms, but were otherwise in good health.
Patients were enrolled within 24 to 48 hours of onset of three or more of the following symptoms: nasal drainage, sore throat, nasal congestion, sneezing, scratchy throat, hoarseness, cough, headache, muscle aches, and fever (oral temperature greater than 98.6 degrees F).
Forty patients were randomized to treatment with zincum gluconicum nasal gel, and 38 patients were randomized to the placebo group. Rhinitis was documented by physical exam. Eighteen of the 78 patients (23 percent) -- seven in the zincum gluconicum group and 11 in the placebo group -- had rhinovirus infection confirmed by microbiological testing of specimens obtained by nasal irrigation.
Patients administered one dose of nasal gel per nostril, four times per day. Treatment endpoints were either resolution of symptoms or completion of the maximum 10-day treatment period. Patients in the zincum gluconicum group used a total daily dose of about 2.1 mg of elemental zinc. Patients in the placebo group used a compound identical to the treatment formulation in all aspects except the active ingredient. Patients were not permitted to use other cold remedies during the study period, such as nonsteroidal anti-inflammatory drugs (e.g., aspirin and ibuprofen), decongestants, antihistamines, or other zinc products.
The median duration of cold symptoms was significantly shorter in the zincum gluconicum group (4.3 days) compared to the placebo group (6 days). Other research has documented a reduction in duration of symptoms as great as 75 percent when the treatment period was extended to as long as 14 days.*
"Patients randomized to the zincum gluconicum nasal gel group experienced a marked reduction in median time to cold resolution and duration of most individual symptoms compared with the placebo group," said Mossad. "Signs and symptoms that showed the most reduction were nasal drainage, nasal congestion, hoarseness, and sore throat."
Mossad noted that the overall incidence of adverse effects was low, with no statistically significant difference between the treated and placebo groups. Occasional nasal stinging or burning sensation was the most common adverse effect reported in both groups.
"We were particularly impressed by the absence of reported gastrointestinal symptoms, such as nausea, that have been described by people using oral formulations of zinc," said Mossad.
According to the National Institutes of Health, people suffer an estimated 1 billion colds in the United States each year. Adults average about two to four colds a year, although the range varies widely. More than 200 different viruses are known to cause the symptoms of the common cold. Cold viruses are typically transmitted by any or all of the following:
-- Touching infectious respiratory secretions on skin and on environmental
surfaces and then touching the eyes or nose.
-- Inhaling relatively large particles of respiratory secretions
transported briefly in the air.
-- Inhaling droplet nuclei: smaller infectious particles suspended in the
air for long periods of time.
The nose is the main portal of entry for cold viruses. The highest concentration of cold virus in nasal secretions occurs during the first three days of infection. This is when infected persons are most contagious.
*Hirt M, Nobel S, Ernesto B. Zinc nasal gel for the treatment of common cold symptoms: A double blind, placebo-controlled trial. ENT J 2000; 79:778-82
Source: Matrixx Initiatives, Inc.; The Cleveland Clinic Foundation