Amphetamine and Related Drugs

Excretion of amfetamine is markedly dependent on urinary
pH, being greatly increased in acid urine. After large doses,
amfetamine may be detected in urine for several days. Under
uncontrolled urinary pH conditions, about 30% of the dose is
excreted unchanged in the urine in 24 h and a total of about
90% of the dose is excreted in 3 to 4 days. The amount
excreted unchanged in 24 h may increase to 74% of the dose in
acid urine and decrease to 1 to 4% in alkaline urine; under
alkaline conditions, hippuric acid and benzoic acid account for
about 50% of the urinary material. Under normal conditions 16
to 28% is excreted as hippuric acid, about 4% as
benzoylglucuronide, 2 to 4% as 4–hydroxyamfetamine, 4 hydroxyamfetamine, and
about 2% as norephedrine in 24 h; small amounts of
conjugated 4–hydroxynorephedrine 4 hydroxynorephedrine and phenylacetone are
also excreted. No elimination in the faeces has been detected.
4/27/2009 ٢٨