ABSTRACT
Despite the rapid proliferation of novel anti-infective agents beginning in the
1960s and continuing through the 1980s, infectious diseases remain the third
leading cause of death in the United States and the second leading cause of death
worldwide (1). Community-acquired pneumonia alone affects approximately
4.5 million adults annually in the United States (2). Therefore, it is not surprising
that antimicrobial agents continue to be among the most commonly prescribed
drug classes. Fortunately, with the exception of life-threatening immediate
hypersensitivity reactions, the toxicity profile of most antimicrobial compounds
is relatively unremarkable. This may be attributed, at least in part, to the rela-
tively short courses (e.g., 2 weeks) of antibiotics given for most common infections. Indeed, with longer courses of antibiotics required for infrequently
encountered chronic infections or in critically ill patients, the risk of renal,
hepatic, hematologic, and other types of serious toxicity significantly increases.
Overall, the incidence of direct cardiovascular toxicity associated with anti-
microbial therapy is very low. While certain antimicrobial compounds may
possess direct cardiodepressant activity, generally this has only been demon-
strated when using supraphysiologic concentrations in vitro or in anesthetized
animals (3). Clinically, such cardiovascular toxicity associated with anti-
microbial administration would not be expected to manifest unless one or more
risk factors or conditions are present such as, but not limited to, diminished
cardiac reserve (e.g., congestive heart failure, circulatory shock), the presence of
cardiac arrhythmias, administration in an immunocompromised host, use of
general anesthesia, presence of sepsis or septic shock, drug overdose, pharma-
cokinetic drug interactions resulting in elevated plasma levels of the antibiotic,
and additive or synergistic pharmacodynamic effects when used in combination
with other drugs possessing inherent depressant activity on the heart or vascu-
lature (4-6). It is due to these many potential clinical factors that have not been
thoroughly studied in the context of cardiovascular drug toxicity that warrants
discussion of the mechanisms underlying the cardiotoxicity of antimicrobials.
