The number of deaths and serious injuries associated with prescription-drug use rose to record levels in the first quarter of 2008, with 4,825 deaths and nearly 21,000 injuries, a watchdog group said Wednesday.
Those numbers represent a nearly threefold increase in deaths from the previous quarter and a 38 percent increase in injuries from last year’s quarterly average, according to the Horsham, Pa.-based Institute for Safe Medication Practices.
The most dangerous drugs were the anti-smoking drug varenicline, linked to 1,001 injuries and 50 deaths in the quarter, and the blood thinner heparin, which was associated with 779 injuries and 102 deaths.
The data came from voluntary reports of adverse effects to the Food and Drug Administration. Because the reporting is voluntary, researchers have estimated previously that fewer than 10 percent of adverse events make it into the system.
The heparin cases were associated with contamination in lots of the drug imported from China. The FDA has reported 238 deaths linked to heparin since January, but the number dwindled once the problem was recognized and addressed.
Varenicline remains an ongoing problem, however, according to institute officials. Since the drug — sold in the U.S. under the brand name Chantix by Pfizer Inc. — was approved in 2006, it has been linked to 3,325 serious injuries and 112 deaths.
Some reports were linked to people attempting suicide or causing other injuries to themselves. Others were linked to blackouts or loss of consciousness, perhaps tied to sudden disturbances in heart rhythm.
One possible explanation for the link might have been the success of the drug and the large number of people using it, the report said.
But investigation showed that, during the quarter, varenicline accounted for more reports of serious injury than the 10 best-selling prescription drugs combined. The institute called for a stronger risk warning on the Chantix label.
Pfizer on Wednesday speculated that the large number of reports might be linked to adverse publicity associated with the drug. It noted also that nicotine withdrawal can cause changes in behavior, such as irritability and depressed mood.
Many of the reports were linked to powerful painkillers or narcotics. Acetaminophen and ibuprofen also appeared among the top 10 drugs causing injuries and deaths.
