Comparative Pharmacology
Head-to-head clinical analysis: ADDERALL XR 15 versus BENZEDRINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADDERALL XR 15 versus BENZEDRINE.
ADDERALL XR 15 vs BENZEDRINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
ADDERALL XR contains a mixture of amphetamine salts, including dextroamphetamine and levoamphetamine. The mechanism of action involves increasing synaptic levels of dopamine and norepinephrine by inhibiting their reuptake and enhancing their release from presynaptic terminals, leading to CNS stimulation.
Benzedrine (racemic amphetamine) releases dopamine and norepinephrine from presynaptic neurons, blocks their reuptake, and inhibits monoamine oxidase, increasing synaptic monoamine levels.
Oral, 20-60 mg once daily in the morning; initial dose 20 mg once daily, titrated by 10-20 mg weekly based on tolerability and efficacy.
Oral: 5-10 mg once or twice daily, maximum 40 mg/day. Intramuscular: 5-10 mg every 30-60 minutes as needed, maximum 40 mg/day.
None Documented
None Documented
The terminal elimination half-life of amphetamine in adults is approximately 10-13 hours; in children, it is slightly shorter (6-8 hours). For the l-amphetamine isomer, the half-life is 9-11 hours. The extended-release formulation provides a prolonged duration of effect due to a biphasic release profile.
Terminal elimination half-life: 4-6 hours in adults (range 4-8 hours). Clinically, duration of action correlates with half-life, but tolerance may develop with repeated dosing.
Renal: approximately 90% of a dose is excreted in urine, with about 30% as unchanged amphetamine and the remainder as metabolites including deaminated and oxidized products; fecal excretion accounts for less than 10%.
Renal (30-40% unchanged, pH-dependent), with minor biliary/fecal elimination. At acidic urine pH, elimination half-life is shortened; at alkaline pH, reabsorption increases.
Category C
Category C
CNS Stimulant
CNS Stimulant