The duration of excretion of detectable amounts of drug in the urine following last intake is highly variable.
A general rule of thumb is five plasma half-lives. This is simply a rough estimate given the following variables: route of
administration, amount of drug taken, frequency of use, individual metabolism, urinary pH, and drug storage within body.
Amphetamines:
one day several
weeks
Barbiturates short acting (e.g. Seco): one day
long acting (e.g. Pheno):
2-3 weeks
Benzodiazapenes
3 days
4-6 weeks
Cocaine Metabolites
2-3 days
several days
Codeine/Morphine
2-4 days
several days
Methadone
2-3 days
1-2 weeks
PCP
up to 1 week 1-2 weeks
Propoxyphene
1-2 days several
days
Marijuana single smoke:
up to 4 days
moderate use:
up to 10 days
heavy use up
to 4-6 weeks
passive inhalation:
negative
Nicotine moderate use:
1-2 days
