Re: The Fluoroquinolone Drugs are the most toxic and dangerous antibiotic in clinical practice todayIn addition to inducing MMP-3 and sometimes damaging tendons after long
use, this class also blocks carnitine transport. I suspect this makes
them a bad idea for autoimmune patients since you need carnitine to
absorb butyrate in the gut and butyrate to acetylate histones and induce
FOXP3 in regulatory T cells. I wouldn't be surprised if long-term use
of fluoroquinolones caused some epigenetic regulatory issues. If you're
concerned about this class of drug, you should keep an eye out in the
literature.
Int J Pharm. 2007 Sep 25; [Epub ahead of print] Related Articles, LinkOut
The inhibitory effects of fluoroquinolones on l-carnitine transport in
placental cell line BeWo.
Hirano T, Yasuda S, Osaka Y, Asari M, Kobayashi M, Itagaki S, Iseki K.
Department of Clinical Pharmaceutics & Therapeutics, Graduate School of
Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome,
Kita-ku, Sapporo 060-0812, Japan.
l-Carnitine plays an important role in lipid metabolism by facilitating
the transport of long-chain fatty acids across the mitochondrial inner
membrane followed by fatty acid beta-oxidation. It is known that members
of the OCTN family play an important role in l-carnitine transport in
the placenta. Investigation of drug-drug or drug-nutrient interaction in
the placenta is important for establishment of safety drug medication
during pregnancy. The aim of this study was to determine the effects of
fluoroquinolones, inhibitors of OCTN2, on l-carnitine transport in the
placenta which is known to have a high expression level of OCTN2. We
investigated the inhibitory effect of five fluoroquinolones,
ciprofloxacin (CPFX), gatifloxacin (GFLX), ofloxacin (OFLX),
levofloxacin (LVFX) and grepafloxacin (GPFX), on l-carnitine transport
mediated by OCTN2 in placental cell line BeWo cells. We found that all
of the fluoroquinolones inhibited l-carnitine transport, GPFX being the
strongest inhibitor. We also found that the inhibitory effects of LVFX
and GPFX depended on their existence ratio of zwitterionic forms as, we
reported previously. Furthermore, we elucidated the LVFX transport
mechanism in BeWo cells. LVFX was transported actively by transporters.
However, we found that LVFX transport was Na(+)-independent and
l-carnitine had no inhibitory effect on LVFX transport, suggesting that
LVFX acts as inhibitor of OCTN2, not as a substrate for OCTN2.
PMID: 17977676