Comparative Pharmacology
Head-to-head clinical analysis: ADDERALL XR 20 versus METADATE CD.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADDERALL XR 20 versus METADATE CD.
ADDERALL XR 20 vs METADATE CD
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.
Methylphenidate is a central nervous system (CNS) stimulant. It blocks the reuptake of norepinephrine and dopamine into the presynaptic neuron, increasing their levels in the extraneuronal space. The precise mechanism for treating ADHD is not fully understood.
20 mg orally once daily in the morning.
20-60 mg orally once daily in the morning
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.
Terminal elimination half-life: 6.8 hours (range 4.5-10.3 hours) for methylphenidate; clinical context: supports twice-daily dosing regimen
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: 78-97% as metabolites (primarily ritalinic acid), unchanged drug <1%; fecal: <2%
Category C
Category C
CNS Stimulant
CNS Stimulant