Which of the following drugs of abuse is detectable in the urine for the longest amount of time?
Drug (screening)
Note that detection times vary considerably from person to person. That being said the following table serves as a rough guide. As a general rule most substances remain positive in the urine for 1-3 days with the exception of heavy users of cannabis who can remain positive for up to 14-28 days.
| Drug of abuse | Length of time detectable in urine |
|---|---|
| Cannabis (heavy use) | 14-28 days |
| Cannabis (single use) | 3 days |
| Phencyclidine | 8 days |
| Methadone | 3 days |
| Morphine | 3 days |
| Benzodiazepine | 3 days |
| Heroin | 3 days |
| Cocaine | 1-3 days |
| Amphetamine | 1-3 days |
| LSD | 1-3 days |
| Codeine | 2 days |
| Alcohol | 12 hours |
(Adapted from Synopsis of Psychiatry, Kaplan & Sadock's)
Standard drugs included in a urinalysis screen include:-
- Cannabis
- Amphetamine
- Cocaine
- Methadone
- Benzodiazepines
- Opiates
