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Phenylephrine–acetaminophen interaction: Clinically significant or not?


In healthy volunteers, administration of phenylephrine in combination with acetaminophen and ibuprofen, compared with phenylephrine alone, led to a 4-fold increase in the maximal plasma concentration of phenylephrine and a 2-fold increase in its area under the curve. Ibuprofen was subsequently found to be noncontributory to these effects. 


Atkinson HC et al. Increased phenylephrine plasma levels with administration of acetaminophen [letter]. N Engl J Med. 2014;370:1171–1172.

Hendeles L et al. Oral phenylephrine: an ineffective replacement for pseudoephedrine [letter]? J Allergy Clin Immunol. 2006;118:279–280.


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