Amphetamine and Related Drugs

Disposition in the Body
Readily absorbed after oral administration. About
70% of a dose is excreted in the urine in 24 h. Under
normal conditions, up to 43% of a dose is excreted as
unchanged drug, up to 15% as 4– 4
hydroxymetamfetamine, and about 5% as
amfetamine, amfetamine,
the major active metabolite. A number
of other metabolites have been identified. Excretion
of unchanged drug is dependent on the urinary pH,
being increased in acidic urine and greatly reduced
(to about 2% of a dose) if the urine is alkaline
4/27/2009 ٤٧