Drug Detection Periods

DRUG	CATEGORY	DETECTION PERIOD^*	PLASMA HALF LIFE
Amphetamines Amphetamine Methamphetamine	stimulant	2-4 days 2-4 days	7-34 hours 6-15 hours
Barbiturates Amobarbital Butalbital Pentobarbital Phenobarbital Secobarbital	sedative-hypnotic	2-4 days 2-4 days 2-4 days up to 30 days 2-4 days	15-40 hours 35 hours 20-30 hours 2-6 days 22-29 hours
Benzodiazepines Diazepam (Valium®) Chlordiazepoxide (Librium®)	sedative-hypnotic	up to 30 days up to 30 days	21-37 hours 6-27 hours
Cocaine Benzoylecgonine	stimulant	12-72 hours	.5-1.5 hours
Cannabinoids (THC/Marijuana) Casual use Chronic use	euphoriant	2-7 days up to 30 days	20-57 hours
Ethanol	sedative-hypnotic	very short^**	2-14 hours
Methadone	narcotic analgesic	2-4 days	15-55 hours
Methaqualone (Quaalude®)	sedative-hypnotic	2-4 days	20-60 hours
Opiates Codeine Hydrocodone Hydromorphone (Dilaudid®) Morphine Oxycodone (Oxycontin®)	narcotic analgesic	2-4 days 2-4 days 2-4 days 2-4 days 2-4 days	1.9-3.9 hours 4 hours 1.5-3.8 hours 1.3-6.7 hours 4-6 hours
Phencylidine (PCP) Casual use Chronic use	hallucinogen	2-7 days up to 30 days	7-46 hours
Propoxyphene (Darvon®) Casual use Chronic use	narcotic analgesic	2-7 days up to 30 days	8-24 hours

* Detection periods vary; rates of metabolism and excretion are different for each drug and user. Detection periods should be viewed as estimates. Cases can always be found to contradict these approximations.

** Detection period depends on amount consumed. Alcohol is excreted at the rate of approximately 1 ounce / hour.