ABSTRACT
I. Introduction 386
II. Etiology 386
III. Epidemiology 387
IV. Clinical Features 389
V. Complications 390
VI. Pathogenesis 390
VII. Medicines Used in the Treatment of Common Cold 392
A. Intranasal Decongestants 393
B. Combinations Containing Decongestant and Antihistamine
(Oral Decongestant) for Systemic Use 393
C. Topical Anticholinergic Agents 394
D. Expectorants and Mucolytic Agents 394
E. Antitussives 394
F. Nonsteroidal Anti-inflammatory Drugs 395
G. Antibiotics 395
H. Nontraditional Treatments 396
VIII. Common Cold Prevention 396
A. Vitamin C 396
B. Zinc Salt Lozenges and Intranasal Zinc 396
C. Interferons 397
D. New Antiviral Agents 397
References 398
I. Introduction
The common cold, also known as acute viral nasopharyngitis or acute viral
rhinosinusitis, is the most common illness in humans. Although it is a mild
respiratory infection, it is a major cause of morbidity and is responsible for
enormous economic losses due to lost productivity and expenditure on medicines
(1-9). It is estimated that in the USA, every year, about 25 million people visit
their family doctors with uncomplicated upper respiratory infections and the
common cold is responsible for 20 million days of absence from work and 22
million days of absence from school (6,8). Recently, a nationwide telephone
survey of US households (n ¼ 4051) revealed that 67% of adults and 87% of American children experienced at least one non-influenza-related viral respirat-
ory tract infection in the last year. The average adult experienced 2.2 episodes
per year, while children less than 18 years old experienced an average of 3.0
annually. The annual expenditure by Americans on over-the-counter (OTC)
drugs for treatment of coughs or common colds was substantial; 69% of those
survey respondents that had colds self-medicate with an OTC product, 8.2%
received prescriptions for antibiotics and 3% for symptomatic therapies. If
these data could be extrapolated to the US population, non-influenza-related
viral respiratory tract infections were responsible for 500 million episodes
annually, and the estimated total cost in the USA approaches $40 billion annually
(5). In Brazil, there are no precise statistics regarding the economic impact of
acute respiratory infections of viral etiology; however, the medications used
for common cold therapy are among the most frequently sold, with or without
medical prescription, and the abusive use of antibiotics is very common (1,2).
