Lisdexamfetamine (Vyvanse) is inactive until hydrolyzed to l-lysine, a naturally occurring essential amino acid, and dextroamphetamine, which is responsible for the drug’s activity.
96% is excreted in Urine (42% as amphetamine-related compounds (dextroamphetamine), 2% as (lisdexamfetamine), 25% hippuric acid; feces (minimal).
Vyvanse elimination half-life is < 1 hour. This basically means that in 1 hour you would have cleared half your dose. For example if you take a daily dose of 70 mg in 1 hour you would clear 35 mg of the drug, and in another hour 17.5 mg etc. The elimination half-life of dextroamphetamine is approximately 9.4-13 hours. Thus dextroamphetamine could take longer to be cleared. Amphetamines may elevate plasma corticosteroid levels and may interfere with urinary steroid determinations. Changes in urinary pH may alter excretion of amphetamines. Urinary acidifying agents increase urinary excretion and decrease serum concentrations and efficacy of amphetamines (cranberry juice, orange juice). Alkalinizing Agents decrease urinary excretion of amphetamines (carbonic anhydrase inhibitors, sodium bicarbonate, antacids such as Tums).
96% is excreted in Urine (42% as amphetamine-related compounds (dextroamphetamine), 2% as (lisdexamfetamine), 25% hippuric acid; feces (minimal).
Vyvanse elimination half-life is < 1 hour. This basically means that in 1 hour you would have cleared half your dose. For example if you take a daily dose of 70 mg in 1 hour you would clear 35 mg of the drug, and in another hour 17.5 mg etc. The elimination half-life of dextroamphetamine is approximately 9.4-13 hours. Thus dextroamphetamine could take longer to be cleared. Amphetamines may elevate plasma corticosteroid levels and may interfere with urinary steroid determinations. Changes in urinary pH may alter excretion of amphetamines. Urinary acidifying agents increase urinary excretion and decrease serum concentrations and efficacy of amphetamines (cranberry juice, orange juice). Alkalinizing Agents decrease urinary excretion of amphetamines (carbonic anhydrase inhibitors, sodium bicarbonate, antacids such as Tums).
