What are the cardiovascular effects of Quinolones (Fluoroquinolones)?

From the Guidelines

Quinolone antibiotics should be prescribed with caution due to their potential to cause cardiovascular side effects, particularly QT interval prolongation, which can lead to potentially fatal arrhythmias. The most concerning cardiovascular effect of quinolones is QT interval prolongation, which can lead to potentially fatal arrhythmias such as Torsades de Pointes 1. This risk is highest with moxifloxacin and patients with pre-existing QT prolongation, electrolyte abnormalities (especially hypokalemia or hypomagnesemia), bradycardia, or those taking other QT-prolonging medications are at increased risk.

Key Considerations

• Quinolones may also cause changes in blood pressure, with reports of both hypotension and hypertension, and rarely can trigger aortic dissection or aneurysm, particularly in elderly patients with risk factors 1.
• The mechanism behind these effects involves blockade of cardiac potassium channels, which affects cardiac repolarization.
• When prescribing quinolones, consider obtaining baseline ECGs in high-risk patients, avoid co-administration with other QT-prolonging drugs, maintain normal electrolyte levels, and choose quinolones with lower cardiovascular risk profiles when possible 1.

Patient Monitoring

• If a patient develops palpitations, syncope, or chest pain while on quinolone therapy, immediate medical evaluation is warranted as these could indicate serious cardiovascular adverse effects.
• Patients with a history of cardiovascular disease, particularly those with heart failure, should be closely monitored while on quinolone therapy, as they may be at increased risk of adverse cardiovascular effects 1.

Alternative Therapies

• In patients with certain cardiovascular conditions, such as congenital or documented acquired QT prolongation, clinically relevant bradycardia, or history of symptomatic arrhythmias, alternative antibiotics should be considered to minimize the risk of cardiovascular adverse effects 1.

From the FDA Drug Label

Some reactions have been accompanied by cardiovascular collapse, hypotension/shock, seizure, loss of consciousness, tingling, angioedema (including tongue, laryngeal, throat, or facial edema/swelling), airway obstruction (including bronchospasm, shortness of breath, and acute respiratory distress), dyspnea, urticaria, itching, and other serious skin reactions Theophylline: SERIOUS AND FATAL REACTIONS HAVE BEEN REPORTED IN PATIENTS RECEIVING CONCURRENT ADMINISTRATION OF CIPROFLOXACIN AND THEOPHYLLINE. These reactions have included cardiac arrest, seizure, status epilepticus, and respiratory failure 5.9 Prolongation of the QT Interval Some fluoroquinolones, including levofloxacin, have been associated with prolongation of the QT interval on the electrocardiogram and infrequent cases of arrhythmia. Rare cases of torsade de pointes have been spontaneously reported during postmarketing surveillance in patients receiving fluoroquinolones, including levofloxacin

Cardiovascular Effects of Quinolones:

• Quinolones, including ciprofloxacin and levofloxacin, may cause cardiovascular collapse, hypotension/shock, and arrhythmia.
• Concurrent administration of quinolones with certain drugs, such as theophylline, may increase the risk of cardiac arrest and seizure.
• Quinolones, including levofloxacin, have been associated with prolongation of the QT interval and torsade de pointes.
• Patients with known prolongation of the QT interval, uncorrected hypokalemia, or those receiving Class IA or Class III antiarrhythmic agents should avoid quinolones.
• Elderly patients may be more susceptible to drug-associated effects on the QT interval 2, 3.

From the Research

Quinolones and Cardiovascular Effects

• Quinolones can cause QT interval prolongation, and should be avoided in patients with known prolongation of the QT interval, patients with uncorrected hypokalaemia or hypomagnesaemia, and patients receiving class IA or class III antiarrhythmic agents 4
• The use of quinolones in elderly patients requires special consideration due to age-related declines in renal function, which may affect the dosing of renally excreted quinolones 4
• There is no direct evidence in the provided studies that quinolones have a significant impact on cardiovascular effects, but studies suggest that quinolones can be used safely in adults with uncomplicated urinary tract infections, with no higher risk of adverse drug reactions compared to other antimicrobials 5

Safety Considerations

• Quinolones should be used with caution in patients with known or suspected CNS disorders that predispose to seizures, and elderly patients should be monitored carefully for CNS excitatory effects 4
• Tendinitis and tendon ruptures are recognized as quinolone-induced adverse effects, and chronic renal diseases, concomitant use of corticosteroids, and age >60 years are known risk factors for quinolone-induced tendopathies 4
• The incidence of adverse drug reactions in the quinolone group was significantly lower compared to the TMP/SMX and nitrofurantoin groups, including the most reported ADRs associated with the gastrointestinal tract 5

Antibiotic Treatment Duration

• Recent studies have demonstrated noninferiority of short-course therapy for a range of conditions, including community-acquired pneumonia, intraabdominal sepsis, gram-negative bacteraemia, and vertebral osteomyelitis 6
• The duration of antibiotic courses increased over the study period, but longer antibiotic courses were no more effective than shorter courses in reducing infection-related hospitalizations 7
• Stewardship programs should recommend shorter courses of antibiotics for acute infections, and further research is required for treating patients with a complex medical history 7

Considerations for Elderly Patients

• Special considerations are required for antibiotic prescription in elderly patients, including individualised dose selection, especially in patients with impaired renal and liver function 8
• Clinicians should be aware of the major drug-drug interactions commonly observed in the elderly, as well as potential side effects, and antibiotic therapy in the elderly requires a comprehensive approach 8