The US Food and Drug Administration (FDA) has asked the makers of fluroquinolone antibiotics to place a boxed warning on the label information for doctors and patients to alert them that this class of drug can increase the risk of tendinitis and tendon rupture in some patients. The Agency has also asked them to develop a Medication Guide for patients.
The increased warning applies only to systemic use of fluoroquinolones, such as in pills, tablets, capsules and injections; it does not apply to topical ophthalmic or otic use, as in eye and ear drops.
These measures will strengthen the existing label warning, and are part of what the agency calls a Risk Evaluation and Mitigation Strategy (REMS) to ensure that the benefits of the drugs outweigh the risks.
The manufacturers have 30 days to comply with the request, or raise reasonable objections, such as changes in wording of the warning. If the FDA does not agree with the objections, it has the power to enforce the changes. The manufacturers are also required to assess the REMS, for instance by surveying patient and doctor awareness that the new warnings are being heeded.
Dr Edward Cox, director of the Office of Antimicrobial Products at the FDA’s Center for Drug Evaluation and Research (CDER), said in a statement released Tuesday that:
“Fluoroquinolones are effective in treating certain bacterial infections, but health care professionals and patients need to be aware of the increased risk associated with the use of these drugs of developing tendinitis and tendon rupture, particularly for certain patient populations.”
The risk of tendinitis and tendon rupture is even greater if the patient taking a fluoroquinolone antibiotic is over 60, or has had a kidney, heart and/or lung transplant, or taking steroids, said the CDER via an alert placed on its website on Monday.
Doctors should advise patients to stop taking the fluoroquinolone, avoid exercise and use of the affected area if they start experiencing any tendon pain, swelling or inflammation, and get in touch with their doctor straight away so they can change to another type of antibiotic, said the CDER alert.
The FDA has approved fluoroquinolones for use treating or preventing certain types of bacterial infections. Like other antibiotics, they are not for treating viral infections like colds and flu.
The agency said that doctors should only prescribe fluoroquinolone for infections that are “proven or strongly suspected to be caused by bacteria”.
A new analysis of the literature and adverse events reported since the drugs have been on the market confirmed that use of fluoroquinolones is associated with an increased risk of tendon rupture, said the FDA, and also shows that despit the current warnings to this effect, patients are still experiencing adverse events in large numbers. So the agency decided to increase the warning level to raise awareness of the risks.
Fluoroquinolone drugs currently approved by the FDA include (with the US brand name and FDA registered marketer in brackets):
- Ciprofloxacin (Cipro from Bayer, also available as generic ciprofloxacin)
- Ciprofloxacin extended release (Cipro XR from Bayer, and Proquin XR from Depomed)
- Gemifloxacin (Factive from Oscient)
- Levofloxacin (Levaquin from Ortho-McNeil)
- Moxifloxacin (Avelox from Bayer)
- Norfloxacin (Noroxin from Merck)
- Ofloxacin (Floxin from Ortho-McNeil and generic ofloxacin)
Other side effects that have been observed with fluoroquinolones include: convulsions, hallucinations, depression, abnormalities in heart rhythm, or severe diarrhea, and the FDA said doctors should assess the benefits against the risks for each patient whenever prescribing this class of antibiotics.
Source: FDA.
Written by: Catharine Paddock, PhD