Chirality Status of Withdrawn Drug Groups
Of the 395 drugs withdrawn, 52.4% (n=207) were achiral, 27.6% (n=109)
were chiral mixtures, and 20.0% (n=79) were pure enantiomers. The mean
TtW of all those drugs evaluated for safety were 24.6±27.5 (0-226)
years, and the time after launch was 57.3±30.1 (8-267) years.
“N-nervous system drugs” had the highest share (26.3%) when
distributed at ATC-1 level. Five of 13 ATC-1 classes were predominantly
chiral. Furthermore, the chiral predominance in “C-cardiovascular
system drugs” were statistically significant when compared to other
classes (p=0.02), (Figure 1).
Chiral mixtures were significantly higher in number than achirals in
cardiovascular system drugs (17.5% vs. 7.7%, p=0.01). In
musculoskeletal system drugs, pure enantiomers were significantly less
withdrawn (2.5%) compared to achirals (12.6%) and chiral mixtures
(11.9%), (p=0.01 and p=0.03, respectively). On the contrary, pure
enantiomers were subject to withdrawal at a higher rate (8.9%) compared
to chiral mixtures (1.8%) in the genitourinary system drugs (p=0.04),
(Table 1).