title: Effect of influenza immunization on CYP3A4 activity.
abstract: A number of clinical reports of drug interactions with influenza vaccine have been made. We hypothesized that CYP3A4 activity would decrease following influenza immunization. Fifteen healthy subjects had erythromycin breath tests (ERMBT) and influenza antibody titer hemagglutinin inhibition assay (HIA) before and after receiving influenza vaccine. The mean age of the subjects was 31.9 years (S.D. 10.2). The change in ERMBT following influenza immunization was not significant (mean -4%, S.D. 17%, P=0.25). Influenza immunization does not significantly change CYP3A4 activity. Changes in serum drug concentrations noted previously after influenza immunization are either due to very small changes in CYP3A4 activity or other pharmacokinetic interactions.
authors.affiliation: University of Wisconsin School of Pharmacy, 777 Highland Avenue, Madison, WI 53706, USA. mshayney@pharmacy.wisc.edu
authors.forename: M S
authors.initials: MS
authors.lastname: Hayney
authors.forename: R J
authors.initials: RJ
authors.lastname: Hammes
authors.forename: J P
authors.initials: JP
authors.lastname: Fine
authors.forename: J A
authors.initials: JA
authors.lastname: Bianco
mesh_terms: D000328:Adult; D001944:Breath Tests; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004917:Erythromycin / Q000008:administration & dosage / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D008099:Liver / Q000201:enzymology; D008297:Male; D006899:Mixed Function Oxygenases / Q000378:metabolism*
chemical_list: D007252:Influenza Vaccines; D004917:Erythromycin; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C104464:CYP3A protein, human; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human