As you may have read, the U.S. Food and Drug Administration announced Thursday that it will require manufacturers of fluoroquinolone antibiotics — the group that includes ciprofloxacin and levofloxacin, among others — to add a black box warning on the product label cautioning doctors and patients about the risk of tendon rupture with these agents.
I first read this online earlier this week, in between patients when I was checking my e-mail. While I duly noted this warning, it concerned me because ciprofloxacin is such an effective drug in many patients with various infections.
It is especially effective in urinary tract infections, both because it treats most of the bacteria that cause these infections and — being excreted by the kidney — the drug concentrates in the urine to achieve high bacterial killing levels.
In short, it is a very good drug.
Now, don't get me wrong. Ciprofloxacin and other drugs in this class were never perfect, just like no drug is perfect. We already knew that it could (rarely) cause problems such as nervous system disturbances, rashes, liver irritations and the like.
But if you look at many drugs that we doctors routinely prescribe, you would often find such potential side effects listed.
Moreover, ciprofloxacin has been on the market — originally brand name, now also generic — for a good number of years.
Most of us, while aware of its potential downsides, still believed that the benefits of use outweighed the risks in the majority of cases.
One had to be a bit careful with this drug, like many drugs. For instance, this drug could not be used in children and adolescents because of tendon problems. Also, the drug had to be administered at a reduced dose among elderly patients and patients with kidney disease.
Immediately after reading this FDA warning, my next patient happened to be a 65-year-old woman with left-side pain.
This pain had been going on for a week and seemed to be getting worse. It was associated with nausea and vomiting, but she did not have bowel complaints, and told me she had not experienced fever, chills or sweats. Nor did she have pain on passing her urine, urine frequency, or noticeable blood in her urine. Her nausea and vomiting were much better today, and she was able to eat and drink normally — reassuring, because it meant that she would be able to keep oral medications down without vomiting them back up.
She had no history of trauma to her side that she could remember.
Many conditions can cause left-side pain, and in her, my initial thoughts were: muscular strain, colon problems, rib problems (for example, recurrence of breast cancer that spread to her ribs), problems with her spleen or a kidney infection.
Because of the severity and worsening nature of her pain — as well as her history of cancer — I obtained a battery of blood tests, a urine test, and I sent her for a CT scan of her chest and abdomen to get a better look at the area.
They were able to schedule the CT scan right away, so, after donating blood and urine to my lab, off she went to have her CT scan.
While she was gone, her labs came back and I was relieved to find that they were normal except for the presence of a urinary tract infection.
In about two hours, she came back to my office. I called the radiologist who was interpreting the CT scan: good news; nothing serious looking in that area.