Diazepam

The half-life of diazepam is 43±13 hours, but ranges from 40-100 hours if the contribution from active metabolites is included. Diazepam is metabolized to nordiazepam which is an active metabolite with a half-life of 40-99 hours.

Zolpidem

Zolpidem has a short elimination half-life (2.2 + 0.4 hours), which is reduced in children (~ 1.4 hours) and increased in the elderly (~ 2.8 hours) and patients with hepatic cirrhosis (~ 9.9 hours)

Diphenhydramine

The plasma half-life is 8.5±3.2 hours.

Gamma-hydroxybutyrate (GBH)

GHB is rapidly eliminated and has a half-life of 27 minutes (range 20-53 minutes).

Carisoprodol

The half-life of carisoprodol is approximately 100 minutes.

Cannabis

THC is highly lipid soluble, and plasma and urinary elimination half-lives are best estimated at 3-4 days, where the rate-limiting step is the slow redistribution to plasma of THC sequestered in the tissues.

Morphine

Morphine has a short half-life of 1.5 - 7 hours.

Close to 90% of a single morphine dose is eliminated in the 72 hours urine.

Heroin

Heroin has an extremely rapid half-life of 2-6 minutes.

Methadone

The half-life of (R,S)-methadone is 15-60 hours, and 10-40 hours for (R)-methadone.

Sumber: National Highway Traffic Safety Administration (www.nhtsa.gov)

Barbiturates

Amobarbital: half life is 15-40 hours (dose dependent). Butalbital: half life is 35-88 hours. Pentobarbital: half life is 35-88 hours Phenobarbital: half life of 2-6 days. Secobarbital: half life is 22-29 hours Thiopental: half life for this drug is 6-46 hours.