The Food and Drug Administration received nearly 21,000 reports of serious drug reactions, including more than 4,800 deaths, said an analysis of federal data by the Institute for Safe Medication Practices, known as ISMP.
Two drugs accounted for a large share of the latest reports. One was heparin, the tainted blood thinner from China that caused an international safety scandal. The other was Chantix, a new kind of anti-smoking drug from Pfizer.
Chantix, which had the most reports of any medication, works directly in a smoker's brain to ease withdrawal symptoms. It also blocks the pleasurable effects of nicotine if the patient is tempted to light up again. Earlier this year, the FDA warned that Chantix may be linked to psychiatric problems, including suicidal behavior and vivid dreams. Pfizer said Wednesday it stands by Chantix, and that the volume of reports might be linked to publicity about the side effects.
"The FDA is aware of the increasing number of reports, and we take them seriously," said spokesman Christopher DiFrancesco. But officials are not sure whether reports are up because problems are getting worse, or simply due to greater awareness about drug safety issues.
The FDA defines serious drug reactions as ones that cause hospitalization, require medical intervention, or place a life in jeopardy. The agency's monitoring system relies on voluntary reports from doctors and is only believed to capture a fraction of overall problems.
The 20,745 cases reported from January through March was 38 percent higher than the average for the previous four calendar quarters, and the highest for any quarter, the report said.
The number of deaths, 4,824, was a nearly threefold increase from the last calendar quarter of 2007. The FDA said heparin was largely to blame.
Previous ISMP research has shown that reports of serious drug safety problems had increased markedly since the late 1990s.
The ISMP study found that heparin accounted for 779 reports of serious problems, including 102 deaths. The FDA, using data that covers a longer time period, has reported 238 deaths possibly linked to heparin.
Heparin "illustrates an example of a significant drug safety problem that was promptly and effectively resolved by the drug manufacturers and the FDA once the issue was detected and understood," the report said.
Not so with Chantix, it concluded.
The FDA should forcefully warn patients taking Chantix that they may have blackouts that could lead to accidents, the report said.
Current warnings say patients may be too impaired to drive or operate heavy machinery, but such language is standard for many medications. The government has banned the drug for pilots.
The report found 15 cases of Chantix patients who appeared to have been involved in traffic accidents, and 52 additional cases involving blackouts or loss of consciousness. The FDA said it taking a second look at the Chantix warnings.
The agency received 1,001 reports of serious injuries linked to Chantix, more than for the 10 best-selling brand name drugs combined.
Chantix "continued to provide a striking signal of safety issues that require investigation and action," the report said. The authors acknowledged Pfizer's concern that publicity may be driving up the number of reports, but concluded there's enough evidence to warrant stronger FDA action.
Pfizer said the total sum of its Chantix data, including results from clinical trials, show the drug's benefits clearly outweigh its risks.
"We stand by the efficacy and safety profile of Chantix," the company said in a statement. "There are few things that provide greater health benefits than quitting smoking. Pfizer is committed to reducing the prevalence of smoking globally. As part of that mission, we want to increase peoples' understanding of the dangers of smoking and the benefits of quitting."See the whole drug safety report by clicking here. <\a>