Therapeutic significance of the drug lag.

This study evaluates the therapeutic significance of those drugs commercially available in foreign countries but not in the United States at the end of 1976. Of 198 drugs reviewed, 14% offered a potential therapeutic advance while 75% appeared to offer little or no advance. Another 10.5% could not be properly evaluated. Division by therapeutic class showed some groups to be disproportionate to the overall percentages. The cardiovascular group had a higher-than-average ratio of drugs that offered major advances, 23%. On the other extreme was the CNS group, for which a review of 37 drugs showed no drugs to represent a major advance. It is concluded that few "breakthrough" drugs in general use in other countries are being kept out of the United States drug market.