More veterinary drug alerts from FDA
By Christie Keith
July 9, 2008
In the last few days, the FDA has banned the use of a human drug in veterinary medicine (at least for food animals), and issued a black box warning — its highest level of alert — about a class of drugs that includes a human drug frequently prescribed in veterinary medicine, one of the most widely used and useful of all veterinary drugs, and a new, widely promoted, veterinary drug, as well.
FDA has ruled that a black box warning must be placed on human drugs in the fluoroquinolone family, which includes the human drug Cipro and the veterinary drugs Baytril (enrofloxacin) and Zeniquin (marbofloxacin), although it does not appear that this warning will be placed on either of those, which are exclusively veterinary drugs:
Fluoroquinolones are associated with an increased risk of tendinitis and tendon rupture. This risk is further increased in those over age 60, in kidney, heart, and lung transplant recipients, and with use of concomitant steroid therapy. Physicians should advise patients, at the first sign of tendon pain, swelling, or inflammation, to stop taking the fluoroquinolone, to avoid exercise and use of the affected area, and to promptly contact their doctor about changing to a non-fluoroquinolone antimicrobial drug.
I’m seeing what I can find out about this risk in animals taking Zeniquin and Baytril, which is sometimes given longterm to dogs and cats who have chronic urinary tract or skin infections. (Marbofloxacin is also given in a cream, combined with prednisone and clotrimazole for topical use; brand name is Aurizon.)
For the time being, I would definitely be very alert to lameness or limb pain in any animal taking Baytril, and contact your veterinarian with any concerns. Be aware that this warning is only one day old, and your pet’s veterinarian may not be aware of it, nor realize that it might apply to Baytril and/or Zeniquin.
FDA also issued a ruling that the cephalosporin class of drugs — which includes Keflex — can no longer be given to animals intended to be used as food (they can still be used on companion animals):
By law, FDA may issue a prohibition order if evidence shows that extralabel use of a drug in food-producing animals has caused, or is likely to cause, a public health risk. In this case, FDA has gathered evidence showing that the extralabel use of cephalosporins in food-producing animals is likely to contribute to the emergence of resistance and compromise human therapies. Given the importance of the cephalosporin class of drugs for treating disease in humans, FDA believes that preserving the effectiveness of such drugs is critical. Therefore, FDA believes it is necessary to take action to limit the extent to which extralabel use of cephalosporins in food-producing animals may be contributing to the emergence of resistant variants.
This ruling goes into effect on October 8, 2008.
UPDATE: I’m thinking that we should assume Baytril at least does have this effect on dogs:
The effects of enrofloxacin on canine tendon cells and chondrocytes proliferation in vitro.
Lim S, Hossain MA, Park J, Choi SH, Kim G.
Laboratory of Veterinary Surgery, College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, South Korea.Enrofloxacin, a fluoroquinolone antibiotic has been used widely in humans and domestic animals, including dogs, because of its broad-spectrum activity and relative safety. The side effects of fluoroquinolone, induced tendinopathy, tendonitis, spontaneous tendon rupture and cartilage damage, remain incompletely understood. In the present study, we investigated the in vitro effects of enrofloxacin on cell proliferation and induction of apoptosis in canine Achilles tendon cells and chondrocytes. Cell growth and proliferation after treating with enrofloxacin for 2-6 days was quantified by a colorimetric 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxyanilide inner salt (XTT) assay. The results showed that enrofloxacin could inhibit the proliferation of canine tendon cells and chondrocytes at increasing concentrations (10-200 microg/ml). The inhibition of proliferation of canine tendon cells and chondrocytes after exposure to enrofloxacin were associated with induction of apoptosis, as evidenced by the typical nuclear apoptotic condensed nuclei found using Hoechst 33258 staining. It was demonstrated that canine tendon cells and chondrocytes treated with 200 microg/ml enrofloxacin for 4 days exhibited apoptotic features and fragmentation of DNA. Enrofloxacin also increased the apoptosis of canine tendon cells and chondrocytes in a dose and time-dependent manner. The results indicate that enrofloxacin inhibits cell proliferation, induces apoptosis and DNA fragmentation, which might explain enrofloxacin-induced tendinopathy and cartilage damage.
Abstract here.
Baytril was banned by the FDA for the use in animals July 29, 2005 citing a hazard to human health. Just thought you should know this. You will find full documentation concerning the serious adverse reactions to this class on http://www.fqresearch.org including the details concerning the banning of Baytril three years ago.
Comment by david fuller — July 9, 2008 @ 5:01 pm
Baytril was banned in FOOD animals only. You are completely wrong about it being banned for veterinary use in dogs and cats.
Comment by Christie Keith — July 9, 2008 @ 6:05 pm
I have updated this post with info about Baytril and dogs.
Comment by Christie Keith — July 9, 2008 @ 6:45 pm
Baytril is one of the few bunny-safe antibiotics, since it has minimal impact on their gut flora (little hindgut fermenters that they are). It’s often prescribed for long-term use in nasty chronic problems like pasteurellosis and vestibular disease (head tilt). I wonder if rabbit vets have noted adverse musculoskeletal effects?
Comment by Megan — July 9, 2008 @ 8:09 pm
Antibiotic aka Anti-life. No life form can ingest an antibiotic without repercussions, just as the name suggests. There are always side effects, from vaginal infections, intestinal flare-ups to who knows what.
I hope what the FDA is trying to do, years too late and long after the barn door has swung closed, is limit what antibiotics can be given to the animals we eat. Humans, due to flagrant misapplication of antibiotics for things like the common cold which is a huge number of rhinoviruses and which antibiotics don’t effect, now have bacterial pathogens that are resistant to a large number of antibiotics in the current pharmacopia.
Compounding our over-usage of antibiotics on ourselves is that current beef cattle management relies on feed lots, where the animals are packed closely together, a prime breeding ground for disease. One of the ways to manage the overcrowding in feed lots is to freely dose the cattle with antibiotics, which then are stored in the tissues and pass up the food chain to us as well as our pets.
If you buy Certified Organic meats, they have not suppsoedly been treated with antibiotics. However, in the past few years, USDA has caved to political pressure, and lessened the requirements for what is now labeled C.O. Sigh.
Comment by Anne T. — July 9, 2008 @ 8:50 pm
I did not mean to imply that it was banned for the treatment of pets. I was simply letting you know that the FDA had taken action regarding the drug is all and thought you might of had an interest as you had made mention of cephalosporins. The FDA took the same actions for Baytril as you had commented on regarding the use of cephalosporins in food-producing animals, for the same reason, that being that it conntributed to the emergence of resistant variants. Bayer fought this ban tooth and nail but finally lost.
Sorry for any confusion and that I was not more percise regarding this.
Comment by david t fuller — July 9, 2008 @ 9:22 pm
You will also find a number of studies involving beagles puppies in which it was clearly demonstrated that the fluoroquinolone class has a profound negative effect on the cartilage of the young dog to be in abundance. It is for this reason that the pediatric use of the fluoroquinolones has been discouraged. You will find those studies as well on the research site.
There is also another study as well as a dear doctor letter issued by Bayer in which baytril was implicated in causing sudden and permanent blindness in cats.
Hope this helps in your research regarding these issues.
Comment by david t fuller — July 9, 2008 @ 9:29 pm
David, I know you have a site dedicated to getting out the word about problems with this class of drugs. I understand that gives you a certain focus.
But the fact that you can’t give Baytril to puppies is not news and it’s no secret. Every vet knows it, and most breeders and many pet owners. There are other drugs for which that is also true.
Nor is the fact that Baytril can cause sudden onset blindness in cats news, nor are there many vets who are unaware of it, at least in my experience. Baytril is not as widely used in felines as canines so perhaps it’s less known. Still — not news.
The black box warning IS news. It’s not just recent, but it did not include Baytril, and it seemed to me that pet owners needed to know that Baytril is in that class of drugs, so they could be aware of the risk, discuss it with their vets, and so that it could come out generally into discussion.
Baytril is a valuable drug in companion animal medicine. It’s not the right drug for every pet or every illness, and like all drugs, it has side effects, which is why we need to do a risk vs benefit analysis on all medications and therapies. My job is just to give people the information they need to make that analysis, not tell them how it will turn out.
I disagree that the analysis will always come down on the side of not giving the drug. Sometimes it is the best choice. But it’s always good to be informed and aware.
Comment by Christie Keith — July 10, 2008 @ 8:46 am
Christie,
I believe this might also include Zeniquin (marbofloxacin) which a number of Veterinary Dermatologists are using for skin infections. My vet perscribed it instead of Baytril because it was newer and more potent?
Katie
Comment by Katie — July 10, 2008 @ 11:00 am
That’s right, Katie, and thus it will also include Aurizon, which is marbofloxacin with pred and clotrimazole!
Great catch and I’m updating, thank you!
Comment by Christie Keith — July 10, 2008 @ 2:21 pm
Glad to see that we are on the same page here. Apparently veterinarians have a far greater understanding of these drugs than the physicians who prescribe them to humans do. You are to be applauded for this. And I state this with the utmost sincerity.
But in comparision to some of the examples you cited, the fact that you can’t give fluoroquinolones to the pediatric population is not news either and it’s no secret. But physicians do it all the time without a second thought. I know of hundreds of kids who have been crippled for life as a result. Kids that will never, ever, walk again. One child was given this for an infection of the fingernail and ruptured the cartilage in both knees. Another was given this for an earache and will now spend the rest of her life in a wheelchair. Her tendons are beyond surgical repair now. This list is endless. In every single case the drug was NOT prescribed for a life threatening illness either, but for a frivolous infection that just about any other antibiotic could have handled with ease.
Nor is the fact that the fluoroquinolones may cause sudden onset of blindness in human patients news either. But few if any treating physicians are aware of this complication. Irreversible peripheral neuropathy as well for that matter.
The black box warning IS news, I agree, but it is a ‘slap in face’ to those of us who have had their lives destroyed by this class. We have been fighting with the FDA for well over a decade now to get adequate warnings and this just plain doesn’t get it. It is nothing more than a ‘box’ around an inadequate warning that has been in existence since 1996, regarding a reaction that the FDA has been aware of since 1982. Few if any treating physicians are even aware that this may occur with the fluoroquinolones, twenty six years later, even though not one year has gone by since 1982 that this was not reported in the leading medical journals. In a survey I conduct on the research site out of thousands of patients who have responded just about EVERY ONE of them stated that one, the physician was unaware of the fact that the reactions they were experiencing were known, listed and published adverse reactions to the fluoroquinolone class, and second, their treating physician DENIED any such association was even possible.
Therefore I commend you and salute you regarding your opinions that “…pet owners needed to know that Baytril is in that class of drugs, so they could be aware of the risk, discuss it with their vets, and so that it could come out generally into discussion.” Any physician that we have raised such an issue with looked at us like we were insane. Perhaps I was being unjust, and perhaps even harsh, to think that a veterinarian would be as ignorant of these side effects as the medical community as whole is. I apologize for that error and if you had taken any offense.
It has been my experience that the overwhelming majority of the treating physician knows NOTHING about the potential side effects of the fluoroquinolone class and denies ANY association with they take place. And by extension this would also include vets, based upon the experiences of tens of thousands of victims, as well as my own.
I seriously think, and I am not being the least bit sarcastic when I state this in the least, that I would have received far better care and perhaps not now be blinded and crippled for life had I seen a vet rather than a physician. You folks seem to care a lot more about your patients than any physician I have seen or spoken to in the past eight years.
On a side note, to avoid any further misunderstandings, I do NOT advocate the total banning of this class. What I DO advocate is the absolute right of the patient to be FULLY informed of the risk that he or she is taking beforehand. This simply does not occur in regards to this class when it comes to treating the human population. There are indeed times when this is the only drug left in the little black bag and the patient is at risk of losing life or limb if it is not employed. I have no argument with that whatsoever. You use the drug. But somehow I do not see an earache or a fingernail infection falling into such a category. Nor do I believe that the 10% of the world’s population who have been prescribed this class had such a life threatening infection either.
Rational use together with a full and complete risk/benefit discussion I have absolutely no problem with. Frivolous use by a clueless physician, indeed I have a huge problem with, for which I make no apologies. I will now spend the rest of life suffering from such ignorance. It is indeed a comfort to know that my pets will not, due to your efforts. I thank you for this small courtesy.
Good luck to all and God bless you for caring enough to try to educate the pet owners. Job well done my friend and I wish you and yours the best. I will now leave you in peace for you have no need of any further input from me. You appear to have an excellent understanding of these issues and what now needs to be done.
Comment by david t fuller — July 10, 2008 @ 9:35 pm
David, I don’t know if you’ll come back, but if you do… I’m so sorry for what you suffered from taking these drugs.
I believe, without anything more than a hunch, that the reason veterinarians are somewhat more aware of the risks of Baytril than physicians are of similar human drugs is simply this: Baytril costs an absolute fortune compared to the drugs more commonly prescribed in veterinary medicine. Since pet health insurance is rarely a factor, and even when the owner has it, it generally doesn’t cover the cost of a drug like Baytril (if it covers drugs at all), vets use it very sparingly, and often don’t use it even when they probably should.
Baytril is also one of the few veterinary-only drugs, which further sets it apart in companion animal practice.
This is very, very different from human practice, where there are a number of available drugs in this class, and they’re no more expensive than many other drugs, and just as likely to be paid for by insurance or other programs.
I suspect the risk of blindness in cats is less known than the dangers to puppies, but in all the years I’ve been doing this, I have never known a vet who wasn’t aware that you can’t give Baytril to puppies. I’m sorry it’s not the case in human medicine.
Of course, it’s not the first time I’ve felt veterinary medicine has the advantage over human medicine!
Comment by Christie Keith — July 10, 2008 @ 11:46 pm
Wow. My dog was on Baytril for a long time with regard to his neck surgeries and infection. His rear leg was very disabled during this time. No one could explain it other than that it may have been wrongly manipulated during surgery when the vet carried him to x-ray while he was under. His leg recovered fully a while after he was off the drug. It took some time but he recovered. I never ever would have thought it was the Baytril. I did so much research on all the drugs he was taking and never found anything about that. I will bet he had tendinitis. I thought the leg hung wrong during surgery. Of course I don’t know what actually happened but this is interesting to say the least.
Comment by Nicole — July 11, 2008 @ 8:41 pm
The extent of my injuries from exposure to these drugs spans two and half decades. My first exposure back in the mid eighties resulted in a blown Achilles tendon and a heart attack. I was thirty years old. No clue that the drug was to blame.
Second exposure resulted in a blown knee and a frozen shoulder as well as a severe drug rash. Again no clue. This exposure also resulted in tremendous joint pain, peripheral nueropathy, and what they call fibromyalgia, as well as a laundry list of other problems. For more than two decades now I have endured chronic tendonitis (of unknown etiology of course).
Third exposure was combined with a medrol dose pack. Bye bye vision. Went from 20/20 to permanent diplopia (double vision) and glasses requiring trifocals as well as prisms. Diagnosis with permanent damage to both the optic nerves and the muscles that control the eyes by two of the leading eye clinics in the United States. Damage induced by the quinolones. I am on my last possible prisms and when these fail I will have to wear an eye patch to see, as well as the glasses. This will eventually lead to complete blindness. I am now legally blind with out these ‘binoculars’ I have to wear. Most times I use voice recognition software as I can barely see to type.
The fourth and last exposure put me in intensive care and damn near killed me. Seizures resulting from the combination of motrin and levaquin. Once again no one suspected the drugs. I have cystic formations on my liver and kidneys, an enlarged liver, pancreatitis attacks, chronic ringing in the ears, permanent double vision, severe rash on my chest, damage to my heart valves, (atrophy), chronic digestive problems, blown knees and ankles, severe tendonitis of the hands and fingers that make the making of a fist all but impossible, chronic and at times debilitating hip pain, all of the nerves in my teeth were destroyed requiring that all the teeth be root canalled, capped and crown, and these are just some of the things that readily come to mind. My brain is in a constant fog and I may have gotten the order of things out of whack here but this is basically my story.
The first script was for pneumonia, the second for a head cold, the third for a minor infection of the epididymitis, and the fourth and fatal one was for a kidney stone (induced by the previous exposure to cipro earlier that year). Other than the pneumonia, none of these infections were life threatening in the least. The fourth exposure was two months of fluoroquinolones beginning with floxin, then cipro and finally levaquin (at a 1000mg a day). The re-exposure to cipro resulted in yet another kidney stone, only this one was properly treated and I have not had one before or since other than these two. Examination of the two stones confirmed that they were predominantly cipro crystals.
I am now a medical mess to which the dozens of physicians who have kept me alive so far have stated that there is NOTHING that can be done to reverse this damage. Sad to say, but I think I would have been far better off, and my family as well, if they had indeed killed me back in 2000. I now have no life to speak of and I will spend the rest of my days in chronic pain to which no narcotic painkiller even puts a dent in. And my name is “Legions”.
I have exhausted my life savings on medical bills, even with insurance, (as well as a second mortgage I have no idea how I am ever going to pay) and will now have to work the rest of life just to survive. I will never be able to retire and everyday is an ungodly struggle just to get out of bed (takes an hour of tendon stretches to even manage that) and go to work. I come home both physically and mentally exhausted and in horrendous pain. Only to get up the next day and do it all over again. I have had to live like this since 1984.
If nothing else this experience has taught me to be tenacious and thankful for the little things in life like a very loving and supportive wife and family.
But I can no longer do things that others take for granted. I cannot walk my dogs, stroll around the mall, watch tv or listen to the radio, read the newspaper (without a magnifying glass)push my grand daughter on a swing, again this list is endless.
I am far too proud for charity for there are others in far worse shape than I who would need it more and I refuse to apply for disability. I have survived for more than forty years working for my food and rent and paying my own way in life and I will continue to do so until such time that it is physically impossible to get out of bed to continue. But I fear that that day is coming sooner than I would like.
I thank you for your concern, it is deeply appreciated, but if you do what you have stated you intend to do then that is more than enough for me. I cannot bear the thought that my senile beagle and long time companion may some day suffer as I do. Even that would be too much for a crotchy, opinionated, hard ass such as I to bear.
I can, and will continue to deal with this as best I can, as I have no choice, he I fear cannot. Too much of a wimp in his old age, but I love him just the same.
(I have raised beagles my whole life and this one, Mad Max, has always been my favorite) Even he has written to the FDA complaining about beagles being used to test these drugs, and I have a picture to prove it. He is sitting in my chair with his paws on the keyboard barking at the computer screen that was displaying the FDA website at the time. Told you he was getting senile in his old age, he thought he might make a difference. But they didn’t listen to him any more than they have ever listened to me. I must be getting senile as well as I still believe that I might just make a difference some day and prevent some other poor soul from suffering as I have. :)
Please don’t pity me, pity those who have no clue what is happening to them as a result of taking these drugs. They deserve your pity far more that I. At least I was able to discern what caused my problems. They don’t even have a clue. And that my friend is far sadder than ANYTHING I have endured the past couple of decades.
Comment by david fuller — July 11, 2008 @ 8:59 pm
Hi,
I was looking at both sides of this issue because several experts working with my dog have differing opinions about the risk/benefits of this drug.
My dog is about 3 1/2 months old right now and has been suffering with possibly life-threatening pneumonia caused by distemper. She’s being treated for that with something else and for the Pneumonia it was suggested that she get twice a day Baytril and PenecilinG injections. The dosage is smaller than most of these studies cite in young dogs and it’s to be given for 7 days. My vet saw some stuff about joint damage to growing dogs and decided to stop giving the Baytril after only one day. She is somewhat better with the pneumonia, but according to the experts we were consulting would have been free of the pneumonia had the combination shots been continued as scheduled. Now my vet wants to order Zithromax in place of Baytril. I wonder if this does more harm than good. Also, is there a better antibiotic for pneumonia than either of these and also without these risks, as I’ve heard that Zithromax has this risk too.
Comment by Pippit — July 29, 2008 @ 6:53 pm
Zithromax resulted in my wife suffering nerve damage as well as inducing fibromyalgia when she was treated with it for pneumonia years ago. So as you can see a bad outcome is possible with any drug strong enough to fight such a viscious infection. Left untreated pneumonia could prove to be fatal.
What drug to use depends upon the root cause of the pneumonia. Pneumonia is usually caused by bacteria, viruses, or fungi. So before you decide how to treat it you have to determine which of three it might be that is causing the problem to begin with.
Antibiotics often used in the treatment of of bacterial induced pneumonia include penicillin, amoxicillin and clavulanic acid (Augmentin, Augmentin XR), and macrolide antibiotics including erythromycin, azithromycin (Zithromax, Zmax), and clarithromycin (Biaxin).
Penicillin was formerly the antibiotic of choice in treating this infection. Penicillin may still be effective in treatment of pneumococcal pneumonia, but it should only be used after cultures of the bacteria confirm their sensitivity to this antibiotic.
Mycoplasma pneumoniae is a type of bacteria that often causes a slowly developing infection. Macrolides (erythromycin, clarithromycin, azithromycin, and fluoroquinolones) are antibiotics commonly prescribed to treat Mycoplasma pneumonia.
All of the drugs mentioned above have side effects. Some quite severe. Whether or not they are used in veterinary medicine I do not know. Perhaps our host here could answer that for us.
So it becomes choosing the lesser of all these evils at this point. Do the research and make an informed decision from there. As well as ask your vet to determine whether this is a viral, bacterial,or fungus induced infection. For that would determine what the proper drug class would be.
Comment by david fuller — July 30, 2008 @ 7:43 pm
I am happy I found this very informative thread in my search for long term adverse effects of Baytril in our bunny. It seems that the use of any drug can be a crapshoot in susceptible individuals. My daughter has used most of the above human antibiotics mentioned in this thread for URI during her 19 years of life, with no adverse effects. To think that those same drugs can be so devastating in other people is amazing to me. Any drug can also become a threat in people that did not have reactions to them initially if they are combined with other medications or if they are administered at a time when the body is not able to handle them, for whatever reason. My mother is now allergic to penicillin, when it never bothered her before. I do understand that if the data is out there of similar adverse effects occuring with the use of a drug, that it should be included in the warnings and patients thoroughly informed. But, how do we assess who will react severely to a drug? If thousands exhibit no problems and one person does, how do you know which one will you be?
I am still looking for the long term effects of Baytril in bunnies. Does anyone know if it can affect the kidneys? My bunny is drinking tons of water and urinating large volumes as well. Nothing shows in the bloodwork or x rays. The Baytril was Rx because of a weepy eye that improves considerably with the drug, but if loosing the kidneys is a consequence, we will take the weepy eye. Except that the eye discharge did show Bordetella, another subject with hardly any information in the internet,other than a description of what it is.
I guess there is no money or interest in researching bunnies for their own health issues, they are only researched for human benefit.
I already searched the HRS site, the best one so far, but with no answers. My vet certainly is at a complete loss also.
Thank you to all the well informed posting for those of us still learning.
Comment by Ivette — September 12, 2008 @ 3:37 am