The researchers sorted FDA risk communications into four categories: warnings about serious adverse events, recommendations against use in specific patient populations, preventing harmful drug-drug interactions, and calls for increased laboratory or clinical monitoring.
The most effective notices were those warning the public about potential serious adverse events, but even these varied in their impact. For example, several studies found that patients shifted away from the diabetes drug rosiglitazone after an FDA alert noted an increased risk of cardiovascular events with this drug. This led to decreased use of rosiglitazone and increased use of other, less risky anti-diabetes drugs.
A similar 2010 FDA warning for asthma patients, however, had little effect. It stressed that one class of asthma medications known as long-acting beta agonists should not be used without an asthma controller medication, such as inhaled corticosteroids. Rates of controller medication use with long-acting beta agonists were low before the FDA warning and did not significantly increase after the advisory was issued.
Recommendations that specific groups of patients avoid certain medications sometimes decreased use, but also produced unintended consequences. The most notable was a series of advisories about the use of antidepressants among children and adolescents. The widely publicized alerts significantly decreased use of these medications by adults as well as children, and one study suggested an unexpected increase in suicides among children and adolescents due to increases in untreated depression.
FDA warnings about harmful drug-drug interactions had some impact, although reductions in co-prescribing that occurred often required repeated risk advisories and took months to years. For example, initial messages to reduce the use of cisapride with contraindicated products were first sent
|Contact: John Easton|
University of Chicago Medical Center