Letter to the editor

Large-Scale Predictive Drug Safety: From Structural Alerts to Biological Mechanisms

The recent explosion of data linking drugs, proteins, and pathways with safety events has promoted the development of integrative systems approaches to large-scale predictive drug safety. The added value of such approaches is that, beyond the traditional identification of potentially labile chemical fragments for selected toxicity end points, they have the potential to provide mechanistic insights for a much larger and diverse set of safety events in a statistically sound nonsupervised manner, based on the similarity to drug classes, the interaction with secondary targets, and the interference with biological pathways. The combined identification of chemical and biological hazards enhances our ability to assess the safety risk of bioactive small molecules with higher confidence than that using structural alerts only. We are still a very long way from reliably predicting drug safety, but advances toward gaining a better understanding of the mechanisms leading to adverse outcomes represent a step forward in this direction.

Despite 2007 law requiring FDA hotline to be included in print drug ads, reporting of adverse events by consumers still low

In 2007 the federal government began requiring drug makers to include in their print direct-to-consumer advertisements information for consumers on how to contact the Food and Drug Administration directly, either by phone or through the agency's website, to report any adverse events that they experienced after taking a prescription drug. Adverse events can range from minor skin problems like itching to serious injuries or illness that result in hospitalization, permanent disability, or even death. Even so, current rates of adverse event reporting are low. We studied adverse event reports about 123 drugs that came from patients before and after the enactment of the print advertising requirement and estimated that requirement's impact with model simulations. We found that if monthly spending on print direct-to-consumer advertising increased from zero to $7.7 million per drug, the presence of the Food and Drug Administration contact information tripled the increase in patient-reported adverse events, compared to what would have happened in the absence of the law. However, the absolute monthly increase was fewer than 0.24 reports per drug, suggesting that the public health impact of the increase was small and that the adverse event reporting rate would still be low. The study results suggest that additional measures, such as more publicity about the Adverse Event Reporting System or more consumer education, should be considered to promote patient reporting of adverse events.

Analysis of behavior-related adverse experiences in clinical trials of montelukast

BACKGROUND

Frequencies of behavior-related adverse experiences (BRAEs) in controlled clinical studies of leukotriene modifier drugs have not been summarized.

OBJECTIVE

We sought to compare the frequency of BRAEs in patients receiving montelukast or placebo in a retrospective analysis of Merck clinical trial data.

METHODS

An adverse experience database was constructed to include all double-blind, placebo-controlled trials of montelukast meeting prespecified criteria. BRAEs (described using the Medical Dictionary for Regulatory Activities controlled vocabulary dictionary) were prespecified to include any term in the Psychiatric Disorders System Organ Class, selected terms related to general disorders, and terms related to akathisia. Frequencies of BRAEs (overall, leading to study discontinuation, and/or serious) were summarized. Analyses estimated the odds ratios (ORs) for montelukast versus placebo based on the frequency of patients with BRAEs in each study.

RESULTS

In total 35 adult and 11 pediatric placebo-controlled trials were included; 11,673 patients received montelukast, 8,827 received placebo, and 4,724 received active control. The frequency of patients with 1 or more BRAEs was 2.73% and 2.27% in the montelukast and placebo groups, respectively; the OR for montelukast versus placebo was 1.12 (95% CI, 0.93-1.36). The frequency of patients with a BRAE leading to study discontinuation was 0.07% and 0.11% in the montelukast and placebo groups, respectively (OR, 0.52; 95% CI, 0.17-1.51). The frequency of patients with a BRAE considered serious was 0.03% in both treatment groups.

CONCLUSION

Reports of BRAEs were infrequent in clinical trials of montelukast. Those leading to study discontinuation or considered serious were rare. Frequencies were similar regardless of treatment group.

Asthma drug use and the development of Churg-Strauss syndrome (CSS)

PURPOSE

Case reports suggest that leukotriene modifier use may be associated with the onset of Churg-Strauss syndrome (CSS). Using pooled data from two nested case-control studies, we examined the association between asthma drug use and the development of CSS.

METHODS

The study was performed in three US managed care organizations and a US national health plan with chart access and complete electronic pharmacy data, with a covered population of 13.9 million. There were 47 cases of possible or definite CSS and 4700 asthma drug user controls identified between January 1, 1995 and December 31, 2002. We examined exposure to asthma drugs in cases and controls, including leukotriene modifiers (6 cases and 202 controls), in the two to 6 months prior to the onset of adjudicated CSS.

RESULTS

While the crude association between use of leukotriene modifiers and CSS was strong (odds ratio (OR) 4.00, 95% confidence interval (CI): 1.49-10.60), in a multivariable analysis controlling for use of oral corticosteroids, inhaled corticosteroids, and number of categories of asthma drugs dispensed, there was no significant association (OR 1.32, 95% CI: 0.44-3.96). Use of inhaled and oral corticosteroids, evaluated as markers of asthma severity, were associated with CSS (OR 3.07, 95% CI: 1.34-7.03 and OR 5.36, 95% CI: 2.51-11.45, respectively).

CONCLUSIONS

No association was found between CSS and leukotriene modifiers after controlling for asthma drug use However, it is not possible to rule out modest associations with asthma treatments given CSS is so rare and so highly correlated with asthma severity, suggesting further investigation is warranted.