Marijuana (THC, cannabis)

General: Marijuana is a widely available, but generally illegal, psychoactive drug known to be used for its euphoric effects for more than 4000 years. Although prepared and administered in numerous possible ways, the most common is smoking of rolled cannabis leaves. It contains over 400 different compounds, including 61 known cannabinoids; however, >2000 compounds may be produced during the process of burning during smoking. The major active constituent is THC, a volatile, viscous oil.

Chemical stability: THC is stable in blood stored at <=5 C for 17 weeks, but may be undetectable by 23 weeks (at least by older methods). It is stable in tubes containing EDTA, heparin, sodium fluoride, and with no anticoagulant. It is less stable in urine, but with somewhat predictable degradation curves at room temperature; frozen, the decrease is less dramatic but more variable (less predictable).

Clinical: Effects have individual variation, but if classic are fairly distinctive, and include:

• Euphoria/relaxation
• Altered time perception
• Lack of concentration
• Impaired learning & memory
• Mood changes such as panic reactions
• Paranoia

• Tachycardia
• Conjunctival suffusion
• Dry mouth & throat
• Increased appetite
• Vasodilation
• Hypopnea