Efficacy and safety of single and multiple doses of pseudoephedrine in the treatment of nasal congestion associated with common cold.

BACKGROUND: Pseudoephedrine (60 mg) is widely used as an oral decongestant taken in tablet or syrup formulations every 4-6 hours for the treatment of nasal congestion associated with common cold and allergy. However, there are relatively few studies in the literature that have used objective measures of nasal airway resistance (NAR) to assess the efficacy of pseudoephedrine, and most studies use only a single dose of medication. The present study has the aims of studying the safety and efficacy of a new pseudoephedrine formulation after single and multiple doses in patients with URTI.

METHODS: The study was a double-blind, randomized, parallel-group, placebo-controlled trial conducted over three study days at a single center. Patients suffering from nasal congestion associated with common cold were recruited and total NAR was measured by the technique of posterior rhinomanometry. NAR and subjective scores of nasal congestion were measured at baseline and after dosing with study medication, every hour over a four-hour period on day 1 after a single dose, and on day 3 after multiple doses of medication. Subjective scores of congestion/stuffiness were also made as a summary score at the end of each day of treatment.

RESULTS: Two hundred and thirty-eight patients with nasal congestion associated with acute upper respiratory tract infection (URTI), mean age 20 years, were recruited to the study and received treatment. After a single dose on day 1 the pseudoephedrine group had a statistically significant lower area under the NAR curve than placebo (p = 0.006) for the primary efficacy variable area under the NAR curve from 0-3 hours (NAR AUC 0-3h), and similarly for the secondary efficacy variable NAR AUC 0-4h (p = 0.001). On day three after multiple doses, the pseudoephedrine group had a statistically significant lower NAR AUC 0-3h and AUC 0-4h than placebo (p < 0.001), On day 1, the pseudoephedrine group had significantly lower subjective scores for congestion than placebo visual analog scale (VAS) AUC 0-3h (p = 0.029) and similarly for VAS AUC 0-4h (p = 0.021). On day 3, the differences in subjective scores were not significantly different. The mean decrease from baseline of the summary score for congestion/stuffiness over the duration of the study was greater in the pseudoephedrine group compared to the placebo group (p = 0.016). On average, heart rate was between two and four beats per minute greater in the pseudoephedrine group compared to placebo. Five adverse events were reported in both treatment groups and these were deemed to be unrelated to treatment.

CONCLUSION: The results demonstrate that pseudoephedrine is a safe and effective treatment for nasal congestion associated with URTI. The results from the laboratory study on day 1 demonstrate by both objective and subjective measures of nasal congestion that a single dose of 60 mg pseudoephedrine is superior to placebo treatment. Support for the decongestant efficacy of multiple doses of pseudoephedrine is provided by objective measures on day 3 and subjective measures made over three days, but not by the VAS scores on day 3.