Garlic, popularly thought to have antiviral properties, also does not appear to shorten the duration of a cold. It may prevent illness, however. A double-blind, randomized controlled trial of 146 patients who were assigned either daily garlic supplementation or a placebo found that participants who took a daily garlic supplement for 3 months had fewer colds.
A less well-known herbal supplement, Pelargonium sidoides (South African geranium), may be effective at alleviating symptoms of the common cold. A Cochrane review of eight randomized clinical trials concluded that there were modest treatment effects for bronchitis in children and adults and for sinusitis in adults. The liquid extract was more likely to be effective than the tablet form.3
Vitamins and minerals
High doses of vitamin C have not been shown to reduce the duration of illness due to upper respiratory infection (URI). A zinc supplement may be effective in reducing the duration of URI illness; however, zinc should not be administered in the nose and should not be used during pregnancy.
Patients may have to look no further than the pantry for an effective cough suppressant. A double-blind, randomized controlled trial involving 300 children aged 1 to 5 years with fewer than 7 days of URI symptoms showed that bedtime administration of 10 g of any of three different types of honey correlated with better subjective sleep scores and less coughing than placebo.4 A Cochrane review of three randomized controlled trials found honey to be better than no treatment or placebo for frequency of cough in children. Honey is not to be used in children younger than age 12 months due to the risk of infant botulism.
A promising new area of research is the role of probiotics in preventing and treating the common cold. A meta-analysis of 12 trials concluded that probiotics were better than placebo for reducing the duration of URIs among adults and the elderly. In other trials, subjects who took probiotics also contracted fewer URIs, used antibiotics less, and had fewer URI-related absences from school. Probiotics or prebiotics are now in the top three types of nonvitamin, nonmineral supplements used by US children.
The bottom line
Treatment of the common cold does not require a prescription pad. Instead, it takes time and patient education.
Kellen Lambeau, DNP, APRN, CNP, is a family nurse practitioner at the Mayo Clinic in Rochester, Minn.
- De Sutter AI, van Driel ML, Kumar AA, et al. Oral antihistamine-decongestant-analgesic combinations for the common cold. Cochrane Database Syst Rev. 2012;2:CD004976.
- Ludwig M, Enzenhofer E, Schneider S, et al. Efficacy of a carrageenan nasal spray in patients with common cold: a randomized controlled trial. Respir Res. 2013;14:124.
- Timmer A, Günther J, Motschall E, et al. Pelargonium sidoides extract for treating acute respiratory tract infections. Cochrane Database Syst Rev. 2013;10:CD006323.
- Cohen HA, Rozen J, Kristal H, et al. Effect of honey on nocturnal cough and sleep quality: a double-blind, randomized, placebo-controlled study. Pediatrics. 2012;130(3):465-471.