Cold and flu tab formulation under the spotlight
A letter published in the New England Journal of Medicine from an Australasian pharmaceuticals company suggests that when combined with paracetamol the level of phenylephrine can effectively be twice the recommendation.
Three randomised, open-label, cross-studies in 30 healthy volunteers were undertaken as part of the development of a new fixed dose combination containing paracetamol, ibuprofen and phenylephrine.
Halving the amount of phenylephrine combined with paracetamol to 5mg total produced a plasma time-concentration similar to that of 10mg phenylephrine administered alone.
The letter stated that the substitution of phenylephrine for pseudoephedrine, because of its use in the illegal manufacture of methamphetamine, has been allowed without any additional safety or efficacy studies.
“Phenylephrine has been called ‘generally recognised as safe and effective’ at oral doses of 10mg on the assumption that the