- Studies on the stereoselective metabolism of citalopram by human liver microsomes and cDNA-expressed cytochrome P450 enzymes
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The involvement of CYP enzymes in the metabolism of citalopram was studied, inclusive the conversion of demethylcitalopram to didemethylcitalopram and the formation of citalopram N-oxide, which both have not been considered previously. Using human mixed liver microsomes and cDNA-expressed CYP enzymes, we confirmed that CYP3A4, 2C19 and 2D6 are involved in the first demethylation step of citalopram, all favouring conversion of the biologically active S-enantiomer. Inhibitor studies indicated that at therapeutic citalopram concentrations CYP3A4 was responsible for 40-50% of demethylcitalopram formation, while the contribution of CYP2C19 increased and that of CYP2D6 tended to decrease with increasing drug concentration, CYP2D6 exclusively mediated the second demethylation step, and citalopram N-oxide was also exclusively formed by CYP2D6. None of the studied CYP enzymes mediated deamination to the propionic acid derivative.
- Olesen, Ole V.,Linnet, Kristian
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- PREPARATION OF ESCITALOPRAM
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Enantiomerically enriched citalopram is prepared by methylating enantiomerically enriched didesmethylcitalopram, obtained by directly resolving racemic didesmethylcitalopram using a chiral acid.
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(2008/06/13)
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- Treatment or prophylaxis of migraine or headache disorders using citalopram, escitalopram or citalopram metabolites
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Methods for prophylaxis of or treating or preventing migraine or migraine headaches, or other headache disorders include administering to a subject in need of treatment a therapeutically effective amount of citalopram, escitalopram, or a racemic or optically pure citalopram metabolite, or pharmaceutically acceptable salts, solvates, polymorphs, or hydrates thereof.
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Page/Page column 11
(2010/02/13)
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