View Full Version : Quercetin interaction with levofloxacin help!

09-20-2010, 04:55 PM
Hello, I am 22 days through a 28 day course of levofloxacin (500mg/day) to treat serratia marcescens prostatitis (I've been sick for 5 years). Unfortunately I have unwittingly been consuming a significant quatity of quercetin during this time. I have consumed the quercetin by boiling 500g of brocolli each day in 1 litre of water for 5 mins to extract the active ingredients (quercetin, myricetin, luteolin) and drinking half in the morning and half at night as a natural remedy for my prostate. I also ate about 30% of the brocolli. The "brocolli water" has helped with my symptoms and I was taking it for several weeks leading up to the antibiotics as well as for 3 weeks into the course. As it was "food" I didn't expect there the be any interaction with the drug until I read the wikipedia page on levofloxacin.
I read on wikipedia and other sites that quercetin inhibits the action of levofloxacin by stopping it from binding to the bacteria.

From wikipedia:
"Quercetin, a flavonol, a kind of flavonoid, may interact with fluoroquinolones, as quercetin competitively binds to bacterial DNA gyrase. Some foods contain high levels of quercetin; whether this inhibits or enhances the effect of fluoroquinolones is not entirely clear."

The quercetin content of brocolli is 30mg/kg plus upto 190 mg of other flavanoids. As I have consumed 500g each day I am worried that I have ruined my chances of the antibiotic curing my illness.

Please look at(there's a link on the levofloxacin page on wikipedia at the botttom [128]:

Hilliard JJ, Krause HM, Bernstein JI (1995). "A comparison of active site binding of 4-quinolones and novel flavone gyrase inhibitors to DNA gyrase". Adv Exp Med Biol. 390: 5969. .

I am not a pharmacologist so I would be very grateful if anyone on this forum could advise me as to the likely effect of consuming such a quantity of quercetin alongside the levofloxacin.

On a scale of 1 to 10 how much has this reduced the effect of the

Will the serratia marcescens become resistant to further treatment?

What should I do? Have another course of levofloxacin?, etc

Many thanks for your knowledge

09-21-2010, 02:33 PM
Valuemd does not give medical advice. If you are in serious help, please call 911 or see your primary care physician. Locking thread.

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