Common cold and influenza symptom management: the use of pharmacokinetic considerations to predict the efficacy of a twice-daily treatment for colds and flu

SUMMARY

Objective: The objective of the two pharmacokinetic studies reported here was to compare the relative bioavailability of an ibuprofen/pseudoephedrine modified-release capsule with each of the active ingredients given alone as standard formulations.

Study design: Evaluation of two open, randomised, cross-over studies, one single dose and one multiple dose, in healthy male volunteers.

Methods: Healthy volunteers were randomised in a cross-over design to single or multiple doses of a combination of ibuprofen (600 mg) plus pseudoephedrine (90 mg) in a slow-release formulation and the individual active products alone as standard formulations; ibuprofen 400mg, pseudoephedrine 60 mg.

Results: The single-dose study demonstrated that the bioavailabilities of ibuprofen and pseudoephedrine achieved with the slow-release formulation were not significantly different from those with standard tablets of each ingredient alone. In addition, mean plasma levels of ibuprofen predictive of clinical efficacy were achieved within 0.5-1 h and lasted for 10-12 h thereafter. The time required to reach clinically effective blood levels of pseudoephedrine was longer, starting at approximately 2 h. However, the plasma levels predicted that the clinical effect would then last for at least a further 12 h. Trough levels from the multiple-dose study showed that clinically relevant analgesic and decongestant plasma levels were maintained for 24 h during twice-daily dosing. The slow-release formulation was well tolerated with only mild adverse events.

Conclusion: Blood levels would predict that the present slow-release fo rmulation of ibuprofen plus pseudoephedrine should offer reliable day and night control of cold and flu and sinus symptoms and be associated with a favourable safety profile.