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 Institute for Safe Medication Practices, based in Horsham, Pa.
The most dangerous drugs were the antismoking drug varenicline, which was 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, which made the data public after stripping it of information identifying victims. Because the reporting is voluntary, researchers have estimated previously that fewer than 10 percent of adverse events made it into the system.
The heparin cases were associated with contamination in drug lots imported from China. The FDA has reported 238 deaths linked to heparin since January, but the number dwindled once the problem was addressed.
Varenicline remains an ongoing problem, however, according to institute officials. Since the drug - sold in the United States under the brand name Chantix by Pfizer Inc. - was approved in 2006, it has been linked to 3,325 serious injuries and 112 deaths.
A Pfizer statement Wednesday speculated that the large number of reports might be linked to adverse publicity associated with the drug. It also noted that nicotine withdrawal can cause changes in behavior, such as irritability and depressed mood. "We stand by ... Chantix when used as directed," the statement said.