Popular Antibiotic Interacts with Thyroid Medication
The British Medical Journal has reported on a several cases of unexplained hypothyroidism in thyroid patients (on levothyroxine) who were taking the popular antibiotic ciprofloxacin. Ciprofloxacin is the generic name for the fluoroquinolone antibiotic sold under the brand names Cipro, Ciproxin and Ciprobay, Cirpoxine, and Ciflox. The drug is primarily used to treat urinary tract infections, pneumonia, and sexually transmitted diseases. Ciprofloxacin was also in the news during the anthrax scare, given its use in treatment for anthrax exposure.What the researchers found in these cases were evidence that oral ciprofloxacin interacts with levothyroxine (i.e., Synthroid, Levoxyl, Levothroid) if taken together. It's thought that the ciprofloxacin may somehow decrease the absorption of the levothyroxine.
In one case, a woman taking 125 mcg a day of levothyroxine took ciprofloxacin (750 mg twice a day) and her TSH level rose to 44 after four weeks. Even when her dosage was raised to 200 mcg a day, her TSH didn't respond. Only when the ciprofloxacin was stopped did the TSH return to normal. In another case, a woman who was stabilized on 150 mcg a day of levothyroxine saw her TSH go from 1.6 to 19 after 3 weeks of treatment with ciprofloxacin at 500 mg twice a day.
What Can You Do?
If you're a thyroid patient who is taking ciprofloxacin, what should you do?
The research suggested that thyroid tests were normalized if patients took the levothyroxine and ciprofloxacin at least six hours apart.
So, if you are on levothyroxine, it makes sense to allow at least six hours apart from taking your ciprofloxacin. And if you have to take the antibiotic for a lengthy period, you should discuss the potential impact on your thyroid with your doctor, and possibly request period thyroid testing to ensure that your thyroid treatment is not affected.
Note: Interestingly, there are also anecdotal reports -- including my own -- of bad reactions to other fluoroquinolone antibiotics. Read about my own experience getting what's known as "floxed," in When Drug Side Effects Get Out Of Hand: Side Effects of Quinolone Antibiotics Like Tequin (Gatifloxacin) Can Be Serious.
You may also want to read my discussion of the book Bitter Pills, along with my Q&A with the author Stephen Fried. The book details Fried's wife's debilitating reaction to quinolone antibiotics, and other drug dangers that are not made public.
Source: Cooper, John, "Ciprofloxacin interacts with thyroid replacement therapy," British Medical Journal, 2005;330:1002 (30 April), Online
Photos: istockphoto.com, Pricegrabber.com
Comments
I was taking generic Cipro and Levothyroxin and had BAD side effects, like severe migraines. One of them lasted 36 hrs. My head hurt extremely bad, I was dizzy and nauseaus. I had to stop taking the Cipro to get relief.
Friends, You won’t believe this, but the first time I was prescribed Cipro was for a thyroid infection! My endo diagnosed a thyroid infection and said that Cipro was the only thing to cure it! I think I better have a talk with him.
Also, our kids are frequently prescribed this for sinus problems, as young as 1 years old. Any news on the effect of this drug on children? Keep bringing these things to our attention, Mary!
Friends: I was prescribed Cipro for the first time to treat a thyroid infection! I better have a talk with my endo! He said it was THE drug to take!
Also, our kids are often prescribed this for sinus infections, as young as 1 years old! Anyone have any info on the safety of this family of drugs for children?
Thanks for alerting us to this Mary!
I recently had a complete thyroidectomy. I developed a bladder infection after the surgery and was put on cipro. Oddly enough, after 4 weeks and my synthroid being raised to 200 mcg, my thyroid levels instead of being in the “hypo” range – moved into the “hyper” range and was just flagged at .004! I wonder if the cipro had anything to do with that???
I developed vitiligo after taking Cipro.
I don’t know if anyone else has had this problem, but the first time I ever noticed a problem with my thyroid (swelling in the throat) was after taking Cipro. I was later diagnosed with hyperthyroidism (graves disease).
WOW- I read the article about the bad reaction to Tequin and I too had a reaction (i am on synthroid and cytomel). I have NEVER been allergic to anything in my life and was diagnosed Tequin for a sinus infection. I was so sick for 3 days with vomiting and diarrehea. I felt as if I had been food poisoned. I have taken Cipro and had no problems. How strange. I have never met anyone that has been put on Tequin and even some doctors had to look it up when I mention it. What else must we go thru?!?!?!
A pharmacist has warned me about the dangers of fluoroquinolone antibiotics. My person experience with three of them has been unpleasant.
Cipro caused me to have a tendon rupture and severe knee problems ever since. The dr told me I would be susceptible for up to a year to get tendon rupture again so not to do anything to strenuous. Those sorts of things the pharmacy will never tell you about.
The TSH effect isn’t the worst one. Flouroquinolones are GABA antagonsists. This means that they can cause seizures in people who have had even unnoticed GABA damage. Benzodiazepines are the usual cause of this GABA insufficiency.
However, anyone who has had a seizure of any magnitude may find that the flourquinolines will precipitate a seizure.
I know that doctors usually ignore this problem and can’t believe that the drug caused these problems when they do occur.
When you are asked if you have any drug allergies, this would be a good time to put into your record any contraindications for flouoquinolones.
Cipro should be avoided for people with type B blood.
EAT RIGHT FOR YOUR TYPE, By Dr. Peter J. D’Adamo, page 239.
I don’t understand why doctors today are so oblivious to these problems, I have Hashimoto’s desease and had a possible infection, I went to a urologist and he put me on Cipro (500mg) twice a day for ten days, and I told him in advance that I had a thyroid problem and was on Synthroid, and he still prescribed Cipro, I did not find out about the interaction or nasty things that this drug can do to you after taking it.It just shows how the big drug company’s manipulate todays medical practice.
Does this medication any collateral damage?
I have seen this drug in a car, my brother, aged 20 years, but he does not complain of any illness!
Itake 150 mcg of Thyroxine daily. I recently had a prolonged kidney infection, taking ciprofloxacin as the third antibiotic to try and cure it. It worked and afterwards (when being treated for stones!) I asked the GP about my thyroid levels and was poo pooed and told there was no connection. On being tested, after insisting, my thyroid levels were at rock bottom and I had to take extra doeses to get it back up again. So this research is worth pursuing.
QUESTION: DOES CIPRO AFFECT ABSORPTION OF ARMOUR TOO?
I WAS RECENTLY TREATED FOR PNEUMONIA WITH CIPRO AND 2 OTHER ANTIBIOTICS. AFTER THAT MY HEART RATE BECAME VERY IRREGULAR AND SOMETIMES WENT AS LOW AS 30 BEATS PER MINUTE. I STILL FEEL LIMP AND EVEN MORE DYSFUNCTIONAL THAN IS USUAL FOR ME,( MY USUAL IS PRETTY DYSFUNCTIONAL!) HAVE AN APPT WITH A CARDIOLOGIST NEXT WEEK,
I DON’T THINK MY PRIMARY DOC KNOWS ABOUT THE CIPRO/SYNTHROID INTERACTION. WE’LL SEE IF THE CARDIO GUY DOES.
WHAT ABOUT ARMOUR?