“The obtained results showed that promazine , a phenothiazine neuroleptic with the simplest chemical structure, significantly inhibited 1-N- and 3-N-demethylation and 8-hydroxylation of caffeine via competitive or mixed mechanism (Ki = 21.8, 25.4 and 58.2 microM, respectively).”
“This indicates inhibition by promazine of CYP1A2 (inhibition of 3-N- and 1-N-demethylation), and possibly CYP3A2 (inhibition of 8-hydroxylation), but not of other CYP isoenzymes involved in 7-N-demethylation of caffeine (e.g. CYP2B2 and/or CYP2E1).”