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Although a large number of specific therapeutic agents are available for treatment of patients with cardiovascular disease, most of these
drugs have never been tested in clinical trials conducted in infants
and children with heart disease. Testing in the pediatric population
has been included only recently as a requirement for gaining Food
and Drug Administration approval for a new drug. Even so, most drugs
currently used to treat infants with cardiac conditions have not
undergone appropriate randomized prospective clinical trials in
this population.
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The number of drugs available to treat cardiovascular disorders is enormous. Rather than attempting to maintain extensive knowledge
about each specific drug, it is much more practical to understand
principles and mechanisms of action according to drug classification.
Practical differences among drugs within a given class are often
of minimal clinical significance. A useful approach is to understand
general mechanisms of action and to become familiar with one or
two specific agents within a given class. In this manner, a small “personal” formulary
can be developed which greatly simplifies the amount of information
necessary to provide appropriate therapy. It is important to stay
current, be alert to new drug developments, and be willing to modify
the approach to drug therapy as new information becomes available.
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As mentioned in the preceding discussion, relatively few drugs have been tested in neonates with heart disease. Thus, any drug
therapy in infants should be founded on sound principles of clinical pharmacology.
Ideally, drug administration is justified only if sufficient data
exist to indicate that the overall morbidity or mortality of the
disease is reduced by therapy and the beneficial effects outweigh
the adverse drug effects. However, information regarding basic and
clinical pharmacology of many drugs is simply not available in the
neonatal population. Drug therapy for infants with cardiovascular
disease is therefore usually extrapolated from studies performed
in adult patients or older children and is often guided by personal
experience, anecdotal reports, tradition, or uncritical acceptance
of drug advertising. Medications are often administered on the basis
of personal belief that a drug is effective, sometimes even in the
face of scientific evidence to the contrary.
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The general concept of rational drug therapy (Table 12-1) is to prescribe drugs in an attempt to maximize efficacy and to minimize adverse drug effects. This implies that therapy is tailored to the
needs of a particular patient and clinical situation. Nowhere is
this more important than in the newborn population. In many instances,
the adverse or toxic effects of a drug in neonates do not become
clear until the drug has been marketed for many years. Even though
a drug is commercially available and has been used in adults, it
may not be equally safe and effective in a newborn with heart disease.
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