PRACTICE RECOMMENDATIONS
> Evaluate liver function before initiating fluoroquinolone (FQ) therapy, and avoid prescribing these antibiotics for patients at increased risk for hepatotoxicity. (c)
> Avoid prescribing FQs for patients with a history of prolonged QT syndrome.
> Closely monitor older patients being treated with FQs, particularly if they have atherosclerosis or epilepsy.
Strength of recommendation (SOR)
(A) Good-quality patient-oriented evidence
(B) Inconsistent or limited-quality patient-oriented evidence
(C) Consensus, usual practice, opinion, disease-oriented evidence, case series
CASE > Sara Z, a 62-year-old patient with a history of chronic urinary tract infections, presents with a 3-day history of dysuria and urinary frequency. Her last 2 urine cultures found Escherichla coli resistant to trimethoprim-sulfamethoxazole, amoxicillin, and cephalosporins. So her family physician ordered a urine culture and prescribed a 7-day course of ciprofloxacin empirically. Five days later, Ms. Z returned, suffering from nonbloody diarrhea and bilateral Achilles tendon pain.
If you were treating Ms. Z, what would your next step be?
Widely used to treat urinary tract, skin, and pulmonary infections and to fight infections resistant to other antibiotics, fluoroquinolones (FQ) are generally regarded as safe in both inpatient and outpatient settings. Yet these broad-spectrum antibiotics are associated with both common and rare adverse effects, as well as a number of drug-drug interactions.
The Centers for Disease Control and Prevention estimates that adverse events from FQs leading to emergency department (ED) visits occur ata rate of 9.2 for every 10,000 prescriptions. That's higher than the ED rates for cephalosporins (6.1 per 10,000) and macrolides (5.1 per 10,000), but far lower than for penicillins (13 per 10,000), clindamycin (18.5 per 10,000), sulfonamides (18.9 per 10,000), and vancomycin (24.1 per 10,000). (1)
In fact, adverse events associated with FQs range from mild and self-limiting to rare and severe. 3bis review discusses both. Relatively common adverse effects and drug-drug interactions are discussed in the text, while the TABLE (2) includes a broader range of potential adverse effects. You'll also find a handout for patients taking FQs on page 195 that clearly describes signs and symptoms that need to be reported right away.
A black box warning of tendinopathies
FQs exhibit an affinity for connective tissue, with higher concentrations found in bone and cartilage than in serum. While FQs are therefore well suited for treating orthopedic-related infections, (3) they also increase the risk of tendinopathies.
In the last 2 decades, numerous case reports linking tendinitis and FQs have been published. (4-6) In 2008, the US Food and Drug Administration (FDA) issued a black box warning of tendinitis and tendon rupture. Patients on FQ therapy should be advised to stop taking the antibiotic at the first sign of pain, swelling, or inflammation in a tendon, the FDA advises. (7)
* How common is this adverse effect? A case-control study of 22,194 patients with a diagnosis of nontraumatic tendinopathy determined that FQ use resulted in a 1.3fold risk of tendon rupture and more than a 4-fold risk of rupture of the Achilles tendon. One Achilles tendon rupture would occur for...