Pharmacology of chlorphenamine and pseudoephedrine use in the common cold: a narrative review.

The common cold is the most frequent upper respiratory viral infection. Although benign, it represents a high socioeconomic burden. Many over-the-counter drugs are available to manage the symptoms of this condition, with antihistamines and vasoconstrictors being the most widely used. This review aimed to compare the potential mechanisms underlying the efficacy and safety of chlorphenamine and pseudoephedrine, the most commonly used agents in these two classes of drugs, and provide a useful perspective to impact appropriate decisions when considering these options for symptomatic common cold treatment. To conduct a comprehensive analysis, we systematically reviewed the use of pseudoephedrine and chlorphenamine using various databases, including MEDLINE, Google Scholar, Scopus, and Embase. We also perused the bibliographies of relevant articles and the EudraVigilance database. The findings suggest that pseudoephedrine may offer specific benefits in rapidly alleviating nasal congestion in the short term. Chlorphenamine appears to exhibit a higher degree of efficacy in alleviating rhinorrhea and other specific cold symptoms compared to pseudoephedrine. Pharmacovigilance data and case report reviews showed that pseudoephedrine may induce a higher incidence of less common but potentially life-threatening adverse effects compared to chlorphenamine. We concluded that antihistamine drugs exhibit a more favorable benefit/risk profile than vasoconstrictors for treating symptomatic common colds.