Chirality Status by Temporal Patterns
The drugs withdrawn were mostly launched between years of 1960-1980 (36.7%) for all chiral groups. Achiral drugs had the highest share in all time periods (48.3%-70.8%). Chiral mixtures were more commonly withdrawn from the market than pure enantiomers in all time periods, except those launched before the year 1920 (4.2% vs. 25.0) and after the year 2020 (5.6% vs. 33.3%), (Table 3).
Mean TtWs of achiral drugs, chiral mixtures and pure enantiomers were similar (25.9±29.1, 20.0±16.9, and 27.9±33.8 years respectively, p>0.05). The drugs withdrawn due to abuse had the highest mean TtW (35.1±28.1 years) and those leading to death had the lowest (11.4±9.6 years). Achiral drugs withdrawn due to dermatological ADRs had longer mean TtW (28.4±20.4 years) compared to that in chiral mixtures (9.3±10.9 years, p=0.01), (Table 4).