Antibiotics and arrhythmias Antibiotics are a class of drugs used to inhibit the growth of bacteria or to kill them, and are widely used clinically to prevent and treat various infectious diseases. Studies have shown that antibiotics have some gastrointestinal reactions, liver and kidney damage and other side effects. Recent studies have found that some antibiotics have serious cardiac side effects, especially those that can lead to malignant arrhythmias – tip-twisting ventricular tachycardia (Tdp). The antibiotics that cause arrhythmias are classified as 1. macrolides: mainly including erythromycin, clarithromycin, azithromycin, etc. These drugs cause arrhythmias including sinus tachycardia, premature atrial beats, premature ventricular beats, atrioventricular block, tip-twisting ventricular tachycardia, QT interval prolongation, etc. 2.Cephalosporins: representative drugs cefradine, cefoperazone, etc. 3, quinolones: sparfloxacin, gatifloxacin, levofloxacin, ofloxacin, etc.. Mainly cause QT interval prolongation, atrioventricular block, premature ventricular beats and other arrhythmias. 4, antifungals: these drugs mainly show QT interval prolongation, tip-twisting ventricular tachycardia, ventricular tachycardia, etc., mainly concentrated in fluconazole, itraconazole and ketoconazole. 5.Anti-malarial drugs: pentazocine, quinine, chloroquine and other drugs can cause QT interval prolongation and tip-twisting ventricular tachycardia. Second, antibiotics induced arrhythmia risk factors 1, congenital factors: such as gender, age, congenital heart disease; a study showed that 66.7% of drug-induced arrhythmias were female. Age is also a risk factor, and age is often correlated with structural heart disease, drug interactions, and decreased drug clearance, so the incidence is significantly higher in older patients. 2. Acquired factors: antibiotics, psychotropic drugs, and amiodarone are the most commonly interacting drugs. Although the occurrence of tip-twisting ventricular tachycardia with amiodarone itself is extremely rare, it is commonly reported that antibiotics in combination with amiodarone predispose to tip-twisting ventricular tachycardia. These interactions can also enhance drug-ion channel binding through inhibition of drug metabolism, or through pharmacodynamic interactions, or both. III. Possible mechanisms of antibiotic-induced arrhythmias Almost all QT interval prolongation drugs act by blocking the rapidly activated delayed rectifierpotassiumcurrent (IKr), which prolongs the cardiac repolarization time course. It can be seen that IKr plays a crucial role in the repolarization of the cardiac action potential. Potassium channel blockade can lead to prolonged cardiomyocyte repolarization and action potential dispersion, thus inducing arrhythmias. The fluoroquinolones and macrolide antibiotics cause arrhythmias precisely by blocking this channel to make the action potential 3 phase prolonged, early repolarization after depolarization, repolarization diffusion, causing QT interval prolongation, which leads to tip-twisting ventricular tachycardia. Before using drugs that may cause arrhythmia, we should fully understand the characteristics of the action of various drugs, their hemodynamic effects and possible side effects; evaluate whether the patient has combined heart disease, cardiac function status, liver and kidney function status, age and gender; pay attention to the principle of individualized medication; correct risk factors that predispose to arrhythmia such as myocardial ischemia, hypotension, cardiac insufficiency, electrolytes, etc. as much as possible before using the drugs. The risk factors of arrhythmia such as myocardial ischemia, hypotension, cardiac insufficiency, electrolyte disorders (especially low potassium) and acidosis should be corrected as much as possible before using the drugs; the adverse effects between drugs should be noted when combining drugs. 2, once the occurrence of arrhythmia should immediately stop the application of the drug, give electrocardiographic monitoring, correct electrolyte disorders. For life-threatening arrhythmias, take measures to correct hemodynamic disturbances and maintain the stability of vital signs.