Comparative Pharmacology
Head-to-head clinical analysis: ADDERALL XR 20 versus AMPHETAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADDERALL XR 20 versus AMPHETAMINE.
ADDERALL XR 20 vs AMPHETAMINE
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.
Amphetamine is a central nervous system stimulant that promotes release of monoamines (dopamine, norepinephrine, and serotonin) from presynaptic terminals and inhibits their reuptake, leading to increased synaptic concentrations. It also reversibly inhibits monoamine oxidase (MAO) and may directly stimulate postsynaptic receptors.
20 mg orally once daily in the morning.
5-60 mg/day orally, divided into 2-3 doses; immediate-release: initial 5 mg once or twice daily, increase by 5 mg increments weekly; extended-release: initial 20 mg once daily in the morning, increase by 10 mg weekly
None Documented
None Documented
Clinical Note
moderateAmphetamine + Torasemide
"Amphetamine may increase the hypotensive activities of Torasemide."
Clinical Note
moderateAmphetamine + Tranilast
"Amphetamine may decrease the sedative activities of Tranilast."
Clinical Note
moderateHydroxyamphetamine + Tranilast
"Hydroxyamphetamine may decrease the sedative activities of Tranilast."
Clinical Note
moderateDextroamphetamine + Tranilast
"Dextroamphetamine may decrease the sedative activities of Tranilast."
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: 10-13 hours (adults) for immediate-release formulations; prolonged to 12-14 hours in chronic use. Clinical context: Half-life correlates with duration of action; twice-daily dosing may be needed.
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%.
Primarily renal (70-80% as unchanged drug and metabolites); minor biliary/fecal (approximately 2-5%). Urinary pH-dependent: acidic pH enhances elimination, alkaline pH reduces it.
Category C
Category D/X
CNS Stimulant
CNS Stimulant