Comparative Pharmacology
Head-to-head clinical analysis: ADDERALL XR 20 versus ADDERALL XR 30.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADDERALL XR 20 versus ADDERALL XR 30.
ADDERALL XR 20 vs ADDERALL XR 30
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 central nervous system (CNS) stimulant. It contains a mixture of amphetamine salts (dextroamphetamine and levoamphetamine). Amphetamines are non-catecholamine sympathomimetic amines that promote release of catecholamines (primarily dopamine and norepinephrine) from presynaptic nerve terminals and inhibit their reuptake, leading to increased synaptic concentrations. The exact mechanism of action in attention deficit hyperactivity disorder (ADHD) is not fully understood but is thought to involve activation of dopaminergic and noradrenergic pathways in the prefrontal cortex.
20 mg orally once daily in the morning.
20-60 mg orally once daily in the morning; start at 20 mg once daily, titrate by 10 mg weekly based on tolerability and response.
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.
The terminal elimination half-life is 10–13 hours for dextroamphetamine (the more active enantiomer) in adults; for the racemic mixture (dextroamphetamine/amphetamine), the half-life is shorter (6–8 hours) due to differential metabolism. Clinical context: Steady-state achieved within 2–3 days; once-daily dosing is sufficient.
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 including dehydroamphetamine and hydroxylated metabolites). Fecal: <4%. Biliary: minimal.
Category C
Category C
CNS Stimulant
CNS Stimulant