A homeopathic cold remedy derived from zinc significantly reduces the severity and duration of common cold symptoms, even when treatment is started as late as the second day of illness, finds a new study.
The study on zincum gluconicum nasal gel was the first trial on its effects on the naturally acquired common cold when starting 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 of the 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."
Dr Mossad said his study, which appears in the January issue of QJM: An International Journal of Medicine, 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 (inflammation of the mucous membranes of the nose). However, he noted that his study is the first to include microbiological confirmation of rhinovirus infection with polymerase chain reaction -a highly sensitive test -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 per cent reduction in time to cold resolution when compared to the placebo group," said Dr 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, makers of Zicam cold remedy zinc nasal gel products, who funded the study.
The study involved 78 patients, between the ages of 18 and 55, who had cold symptoms, but were otherwise in good health. Forty patients received the zincum gluconicum nasal gel, and 38 patients took a placebo. Rhinitis was documented by physical exam. Eighteen of the 78 patients (23 per cent) -seven in the zincum gluconicum group and 11 in the placebo group - had rhinovirus infection.
Patients administered one dose of nasal gel per nostril, four times per day. Treatment ended either when symptoms finished or after 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 (eg 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).
"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 Dr Mossad. "Signs and symptoms that showed the most reduction were nasal drainage, nasal congestion, hoarseness, and sore throat."
He 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 Dr Mossad.