Abstract

BACKGROUND AND OBJECTIVES:

Dextromethorphan is the most commonly used ingredient in U.S. over-the-counter (OTC) cough preparations. The present study examined dosing patterns and patients’ perception of effectiveness from an unbranded dextromethorphan product in the OTC setting.

METHODS:

The study used a prospective, open-label, single-arm design and was conducted at eleven geographically-dispersed U.S. consumer research centers. Of 431 adults screened, 421 completed the study (mean age 41, range 18–66 years old). All had cough due to a cold or influenza, which began ≤ 72 hours before a study visit where dextromethorphan syrup was dispensed. Data were gathered via telephone following a 3-day use period. Participants were asked to follow the dosing instructions of the product’s labeling and dosing information was collected to evaluate dose amount and frequency of daily intakes. Participants’ perceptions of effectiveness (defined as cough symptom relief) and overall satisfaction with the medicine were scored on a 5-point scale. Adverse events were collected to assess tolerability.

RESULTS:

Dextromethorphan syrup was used a median of twice daily for a median daily dose of 60 mg. Of 421 participants, 386 (92%) reported good to excellent cough symptom relief, and 381 (90%) were somewhat to extremely satisfied with the medication. No serious or severe adverse events were reported.

CONCLUSION:

While these results provide valuable consumer insights under ‘in home’ use conditions, they cannot be seen as evidence for dextromethorphan’s clinical efficacy since the study had neither a placebo nor a no-treatment arm.