Peter,
Half-life time is only one component of the broad PK/PD picture. Also, half-life can be misleading if we do not know Cmax, Tmax and Cmin-effective, as well as CNS penetration and clearance from it.
Usually rate of clearance is not doses depended and is predictable, in relation to t1/2. Drug will have effect as long as blood conc. is higher than Cmin-efe., not what is t1/2. However, if we are talking about specific metabolite or excretion as clearance route, than time of drug effect may vary from person to person.
In recent chronic insomnia study NBIX INCREASED drug dose to improve *Sonata* performance in last period of the sleep. They show significant increase in TST and WASO reduction, without side effects. Modified release formulation is, this days, just technicality, not science.
Still, many questions need to be addressed before anyone can say that NBIX have break-true insomnia drug.
BTW, Sonata does not have any next day residual effect, none after 4 hr post dosing.
<<Consistent with the rapid clearance of zaleplon, impairment of psychomotor function was no longer present as early as 2 hours post dosing in one study, and in none of the studies after 3-4 hours.>>
Regards the SEPR, yes they have 2 years lead in regards the plan for NDA file. However, I am bit cautious about drug side effects at effective dose. Without details, I am neutral.
Miljenko |
