Comparative Pharmacology
Head-to-head clinical analysis: ADDERALL XR 20 versus ADDERALL XR 25.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADDERALL XR 20 versus ADDERALL XR 25.
ADDERALL XR 20 vs ADDERALL XR 25
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Adderall XR 20 is a combination of amphetamine enantiomers (dextroamphetamine and levoamphetamine). It increases synaptic levels of dopamine and norepinephrine by inhibiting their reuptake and promoting their release from presynaptic terminals.
Adderall XR is a combination of dextroamphetamine and amphetamine, which are non-catecholamine sympathomimetic amines that promote release of catecholamines (primarily dopamine and norepinephrine) from presynaptic nerve terminals and inhibit their reuptake, resulting in increased synaptic concentrations. This leads to CNS stimulation.
20 mg orally once daily in the morning.
20-60 mg orally once daily in the morning; starting dose 20 mg, titrate weekly by 10-20 mg based on response and tolerability.
None Documented
None Documented
Approximately 10-13 hours for d-amphetamine and 13-15 hours for l-amphetamine in adults; in children, 9-11 hours. The extended-release formulation provides a prolonged therapeutic effect masking shorter elimination.
Dextroamphetamine: 10-13 hours; levoamphetamine: 11-14 hours. Effective half-life supports once-daily dosing with extended duration.
Approximately 90% of an oral dose is excreted renally, with 30% as unchanged amphetamine and the remainder as metabolites (including hippuric acid, benzoic acid, and hydroxylated derivatives). Fecal/biliary excretion accounts for <10%.
Renal: approximately 90% (30-40% unchanged, remainder as metabolites); fecal: minimal (<2%) via biliary elimination.
Category C
Category C
CNS Stimulant
CNS Stimulant