Fluoroquinolone antibiotics: tendon, nerve and mental health reactions

Fluoroquinolones work well against a range of bacteria, but a pattern of rare, serious and sometimes permanent harm led to restrictions in 2019. In August 2023 the MHRA reminded prescribers that, despite those measures, a new study showed no change in UK prescribing patterns and the agency was still receiving Yellow Card reports.

In January 2024 the MHRA went further. The licensed indications for all systemic fluoroquinolones were updated so they should only be used when other antibiotics commonly recommended for the infection are inappropriate. Examples given include resistance to other first-line antibiotics, medicines that cannot be used in that person, earlier side effects from other antibiotics that forced treatment to stop, or treatment failure. Prescribing for non-severe or self-limiting infections, or non-bacterial conditions such as chronic non-bacterial prostatitis, remains discouraged.

Tendon inflammation (tendinitis) and rupture are the best-known reactions. The Achilles tendon is the one most often discussed, but the MHRA says other tendons can be involved. The NHS page for ciprofloxacin describes muscle weakness and pain or swelling in joints or tendons that often begins in the ankle or calf, could also affect the shoulder, arms or legs, and can happen in the first 2 days or even several months after stopping. It adds that this is more common in children.

People over 60, people with kidney impairment and people who have had a solid-organ transplant are at higher risk of tendon injury, and the MHRA says doctors should take special care with them. Taking a corticosteroid at the same time can make tendon injury worse, so the combination should be avoided where possible.

• Pain or swelling near the heel, calf, shoulder or another tendon

• Muscle pain or weakness that is new since starting the antibiotic

• Joint pain or swelling in the shoulders, arms or legs

• Advice from the MHRA for patients: rest the painful area until you can see your doctor

Nerve effects include persistent pins and needles, tingling, tickling, numbness or burning, weakness in the arms or legs and difficulty walking. These can be signs of peripheral neuropathy, which in this setting may not settle quickly. Psychiatric and central nervous system effects listed by the MHRA include severe tiredness, depressed mood, anxiety, memory problems and severe sleep problems. The MHRA has separately reminded prescribers to remain alert to suicidal thoughts and behaviours with fluoroquinolones.

Sensory changes are also listed: altered vision, taste, smell or hearing. The NHS lists tinnitus, loss of taste and double vision among the symptoms of ciprofloxacin that need medical attention.

The MHRA recognises that people who have long-lasting or disabling effects can find their mental health affected, particularly when they feel clinicians do not acknowledge a link with the antibiotic. Being believed, and having the reaction written into the record, is part of the response.

Separate MHRA warnings describe a small increased risk of aortic aneurysm and dissection with systemic and inhaled fluoroquinolones, particularly in older patients, and a small risk of heart valve regurgitation. For people with conditions that predispose them, such as a family history of aneurysm disease or a previously diagnosed aortic aneurysm or dissection, the MHRA says fluoroquinolones should only be used after careful benefit-risk assessment and after considering other options.

Sudden severe chest, back or abdominal pain, or new breathlessness and palpitations, after taking one of these antibiotics needs urgent medical attention.

Stop taking the antibiotic and contact your doctor immediately if you have any of the signs listed above. Do not wait to finish the course, and do not return to the medicine without medical advice. The MHRA says there are no proven drug treatments for these long-lasting effects, so stopping early to avoid further exposure is the key step, and symptoms should be investigated properly.

If you need a similar antibiotic in future, tell the prescriber that you have had a reaction. The MHRA advice is that anyone who has had a serious reaction to a quinolone or fluoroquinolone should avoid them in the future.

Suspected reactions can be reported on the MHRA Yellow Card website or app by patients and carers as well as healthcare professionals. Ask for the reaction to be recorded by name in your GP and hospital notes. Because several antibiotics have brand names that do not reveal the class, the MHRA advises patients to check the details of all antibiotics they are given.