Flurazepam is a "classical" benzodiazepine; some other classical benzodiazepines include diazepam , clonazepam , oxazepam , lorazepam , nitrazepam , bromazepam , and clorazepate .  Flurazepam generates an active metabolite with a very long elimination half-life .  Flurazepam could be therefore unsuitable as a sleeping medication for some individuals due to next-day sedation; however, this same effect may also provide next-day anxiety relief. Residual 'hangover' effects after nighttime administration of flurazepam, such as sleepiness, impaired psychomotor and cognitive functions, may persist into the next day, which may impair the ability of users to drive safely and increase risks of falls and hip fractures . 
In the mid 1980s, the neuroactive steroids 3α,5α-tetrahydroprogesterone or allopregnanolone (3α,5α-THP) and 3α,5α- tetrahydrodeoxycorticosterone (3α,5α-THDOC) were shown to modulate neuronal excitability via their interaction with GABA A receptors. The steroids 3α,5α-THP and 3α,5α-THDOC were able to enhance the GABA-elicited Cl − current.  In addition, these steroids might enhance the binding of muscimol and benzodiazepines to GABA A receptors.  Structure- activity studies (SAR) showed that the 3alpha-OH group is essential for the anesthetic actions of these steroids,  they also have an optimally-placed hydrogen bond accepting group on the β face of the steroid at the C-17 position. The four steroid rings form a rigid framework for positioning these hydrogen groups in three-dimensional space.  Analogues 5 and 6 (Figure 10) are weak modulators of GABA A receptor function because the flexible side chains in these analogues do not have the conformations required for high biological activity.