While I am no big fan of the PPI meds long term,
they still should have limited use in medicine, IMO.
This indicates the PPI meds will in time
all receive the Prilosec to Nexium type
improvement.
1: World J Gastroenterol.
2008 Apr 28;14(16):2617-9.
Is the required therapeutic effect always
achieved by racemic switch of
proton-pump inhibitors?
Zhou Q, Yan XF, Pan WS, Zeng S.
Department of Clinical Pharmacy,
The 2nd Affiliated Hospital,
School of Medicine, Zhejiang University,
Zhejiang 310009, China.
zhouquan142602@[EMAIL PROTECTED]
of the drugs currently used in medical practice
are racemates. The enantiomers of a racemic drug
differ in pharmacodynamics and/or pharmacokinetics,
thus in some cases it is preferable to develop
pure enantiomers by racemic switch. In a recent
study by Pai et al, dexrabeprazole
[R(+)-rabeprazole] (10 mg) was found to be
more effective than rabeprazole (20 mg) in the
treatment of gastroesophageal reflux disease.
We read with great interest in this study and
discussed whether such racemic switch would be
applicable to other proton-pump inhibitors (PPIs).
A literature review indicates that stereoselective
pharmacokinetics, rather than stereoselective
pharmacological activity, is the main cause of
differences in clinical efficacy between pure
enantiomer and racemic PPI. Racemic switches of
PPI provide the therapeutic advantages such as
reducing metabolic load on the body, simplifying
pharmacokinetics, providing benefit to the
non-responders to standard dose of racemate,
more homogenous response to treatment and
better efficacy with equal safety.
Further studies in quantitative structure-activity
relation****ps (QSARs) are needed to address the
fact that the preferred enantiomer of PPI is not
always in the same absolute configuration,
i.e. S-form is for omeprazole, pantoprazole
and tenatoprazole whereas R-form is for
lansoprazole and rabeprazole.
PMID: 18442220
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