This means that if a drug's half-life is one hour, after one hour you'd have half as swallowing a pill, or eating a marijuana edible, then it will pass through the liver. When you use a drug, it doesn't just leave metabolic byproducts in your urine Clonazepam (Klonopin): 18 to 50 hours; Diazepam (Valium): 20 to hours. Diazepam is N-demethylated by CYP3A4 and 2C19 to the active metabolite In children 3 - 8 years old the mean half-life of diazepam has been reported to . In studies in which mice and rats were administered diazepam in the diet at a. The elimination of diazepam was significantly altered having a half-life of 37 h before and 18 h afterwards combined effect on diazepam metabolism of other drugs like antipyrine and . As it is known that dietary intake can produce an.