I, for one, am personally disappointed that the FDA dismissed the citizen petition on mitochondrial toxicity. As far back as 1996 researched showed “the loss in mtDNA was associated with a delayed loss in mitochondrial function. Here, we report that the 4-quinolone drug ciprofloxacin is cytotoxic to a variety of cultured mammalian cell lines at concentrations that deplete cells of mtDNA.”(1)
It is my opinion that true source of chronic and delayed damage associated with the fluoroquinolones, lies in damage and dysfunction wrought about at a sub-cellular level, mainly the mitochondria. Denying this possibility when documented evidence and mountains of anecdotal evidence exists is disappointing.
For mitochondrial toxicity syndrome, Dr. Bennett believes, the risk could be mitigated with a simple genetic test. But, before this test can be developed, the risks must be acknowledged.
Right now the FDA is not acknowledging even the risk of mitochondrial toxicity.
This denial is occurring even when their own 2013 internal memo hinted at mitochondrial toxicity as the source of peripheral neuropathy.
I wholeheartedly agree with Dr. Bennett that, at the very least, the acknowledgement of mitochondrial toxicity must take place so that the mitochondrial avenue can be opened and explored. That is the avenue that could lead to testing and further research to help those already harmed by the fluoroquinolones.
I think it was no coincidence that the FDA denied the mitochondrial citizen petition during the same time frame that they approved label changes. However, before we claim a community victory on cautionary labeling, we must be sure that the FDA acts and acts appropriately on these labels changes.
When speaking to Christian Betancourt of The Duncan Banner FDA press officer Theresa Eisenman said there was no exact date for the new labels to be utilized or what would happen to drugs already in the market with the older labels.
Eisenman said “This is the beginning of the safety label change process and some of the exact language may change before the labels are finalized,” she said. “The Sponsors will have an opportunity to respond to the labeling changes notification and engage in discussions with the Agency. FDA intends to complete the safety labeling changes process as soon as possible.”(3)
Right now, we do not know what the final wording will look like on the fluoroquinolone labels after it has been reviewed by all sponsors and approved by the FDA. As a matter of fact, I do not know who exactly all the sponsors are, but I assume there will be input from multiple sources including pharmaceutical companies on the final label wording.
Call me pessimistic if you will, but given the FDA’s past track record, I will not happy with the fluoroquinolone label changes until I see what the final wording is and how it will be implemented.
Even then, it will be bittersweet, as I will not give up this fight until we acknowledge and understand the basic mechanisms that cause fluoroquinolone adverse events and there are treatments in place for those already suffering.