Does Zinc Nasal Spray Trump
Zinc Lozenges for the Common Cold?

By Matt Brignall, ND

Healthnotes Newswire (November 9, 2000)?A nasal spray containing zinc reduces the duration of symptoms of the common cold, according to a study published in the Ear, Nose and Throat Journal.¹

The authors recruited 213 people who had cold symptoms for less than 24 hours. They were then randomized to receive treatment with either zinc nasal spray (Zicam^®) or placebo. The zinc or placebo sprays were given four times daily until symptoms subsided.

The average duration of symptoms after the beginning of treatment was 2.3 days in the people receiving zinc, compared with 9.0 days in those receiving placebo. A slight tingling or burning sensation upon treatment was reported by roughly 40% of the people in both the zinc and placebo groups. No other side effects were noted.

The 74% reduction in symptom duration seen in the zinc nasal spray group was much greater than the 42 to 53% reduction reported in trials using zinc gluconate or zinc acetate lozenges to treat people with the common cold.^{2 3 4} Zinc gluconate has not significantly reduced duration of cold symptoms in children in clinical trials, for reasons that are not clear. Forms of zinc other than gluconate or acetate have not been found to be effective for the treatment of the common cold.^{6 7}

The mechanism by which zinc speeds resolution of the common cold is not entirely clear. Zinc may block the ability of viruses to infect cells in the nose, or zinc may kill viruses on contact.^{8 9} Since the common cold is caused by viral infection of the nasal cavity, and since zinc?s beneficial effect appears to occur when zinc makes physical contact with the virus, it makes sense that a method of application that puts zinc directly in the nose would have a more powerful effect than would oral dosing. However, more studies confirming these results are needed before this nasal spray will replace oral zinc lozenges as the treatment of choice for the common cold.

References:

1. Hirt M, Nobel S, Barron E. Zinc nasal gel for the treatment of common cold symptoms: a double-blind, placebo-controlled trial. Ear Nose Throat J 2000;79:778?80.
2. Prasad AS, Fitzgerald JT, Bao B, et al. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trial. Ann Intern Med 2000;133:245?52.
3. Mossad SB, Macknin ML, Medendorp SV, Mason P. Zinc gluconate lozenges for treating the common cold. A randomized, double-blind, placebo-controlled study. Ann Intern Med 1996;125:81?8.
4. Godfrey JC, Conant Sloane B, Smith DS, et al. Zinc gluconate and the common cold: a controlled clinical study. J Int Med Res 1992;20:234?46.
5. Macknin ML, Piedmonte M, Calendine C, et al. Zinc gluconate lozenges for treating the common cold in children. A randomized controlled trial. JAMA 1998;279:1962?7.
6. Eby G. Where?s the bias? Ann Intern Med 1998;128:75 [letter].
7. Garland ML, Hagmeyer KO. The role of zinc lozenges in treatment of the common cold. Ann Pharmacother 1998;32:63?9 [review].
8. Korant BD, Kauer JC, Butterworth BE. Zinc ions inhibit replication of rhinoviruses. Nature 1974;248:588?90.
9. Novick SG, Godfrey JC, Godfrey NJ, Wilder HR. How does zinc modify the common cold? Clinical observations and implications regarding mechanisms of action. Med Hypotheses 1996;46:295?302.

Matt Brignall, ND, is a research associate at the Tahoma Clinic in Kent, Washington, and a contributor to the Healthnotes Review of Complementary and Integrative Medicine and Healthnotes Online.

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