Market withdrawal of new molecular entities approved in the United States from 1980 to 2009.

Economic factors, market dynamics, and safety issues are largely responsible for decisions to withdraw pharmaceutical products from the market. In this study, new molecular entities (NMEs) approved by the Food and Drug Administration (FDA) were examined in the USA from 1980 to 2009. Data were obtained from the FDA, Micromedex, Medline, and Lexis-Nexis. Descriptive analyses were used to classify product discontinuations by therapeutic category, time frame for discontinuation, and reason for withdrawal. There were 740 NMEs approved by the FDA during the study period. As of 1 December 2010, the number of drugs discontinued was 118 (15.9%). Discontinuations were the highest for antiparasitic products, insecticides, and repellents (6, 33.3% of approvals), systemic hormonal preparations excluding sex hormones and insulins (5, 33.3%), musculo-skeletal system (11, 32.4%), diagnostic agents (16, 28.1%), and anti-infectives for systemic use (27, 25.2%). Safety was the primary reason for withdrawing 26 drugs (3.5% of approvals). Approximately one in seven approved NMEs were discontinued from the market in the period of 1980-2009. Less than one-quarter (22%) of the total withdrawals were attributed to safety reasons. An ongoing evaluation of new drugs throughout their product life cycle is important to determine their efficacy, safety, and value to society.

Qureshi ZP ，Seoane-Vazquez E ，Rodriguez-Monguio R ，Stevenson KB ，Szeinbach SL ... -  《-》

Patent life of antiretroviral drugs approved in the US from 1987 to 2007.

Rodriguez-Monguio R ，Seoane-Vazquez E 《-》

Drug-review deadlines and safety problems.

The Prescription Drug User Fee Act (PDUFA) imposes deadlines for the completion of drug reviews by the Food and Drug Administration (FDA). Critics have suggested that these deadlines may result in rushed approvals and the emergence of unanticipated safety problems once a product is in clinical use. We assessed the association between the PDUFA deadlines and the timing of FDA drug approval by constructing dynamic Cox proportional-hazards models of review times for all new molecular entities approved between 1950 and 2005. To determine whether the deadlines were associated with postmarketing safety problems, we focused on drugs submitted since January 1993, when the deadlines were first imposed. We used exact logistic regression to determine whether drugs approved immediately before the deadlines were associated with a higher rate of postmarketing safety problems (e.g., withdrawals and black-box warnings) than drugs approved at other times. Initiation of the PDUFA requirements concentrated the number of approval decisions made in the weeks immediately preceding the deadlines. As compared with drugs approved at other times, drugs approved in the 2 months before their PDUFA deadlines were more likely to be withdrawn for safety reasons (odds ratio, 5.5; 95% confidence interval [CI], 1.3 to 27.8), more likely to carry a subsequent black-box warning (odds ratio, 4.4; 95% CI, 1.2 to 20.5), and more likely to have one or more dosage forms voluntarily discontinued by the manufacturer (odds ratio, 3.3; 95% CI, 1.5 to 7.5). PDUFA deadlines have appreciably changed the approval decisions of the FDA. Once medications are in clinical use, the discovery of safety problems is more likely for drugs approved immediately before a deadline than for those approved at other times.

Carpenter D ，Zucker EJ ，Avorn J 《-》

Canadian and US drug approval times and safety considerations.

Rawson NS ，Kaitin KI 《ANNALS OF PHARMACOTHERAPY》

Postmarketing drug dosage changes of 499 FDA-approved new molecular entities, 1980-1999.

Cross J ，Lee H ，Westelinck A ，Nelson J ，Grudzinskas C ，Peck C ... -  《PHARMACOEPIDEMIOLOGY AND DRUG SAFETY》