Comparative Pharmacology
Head-to-head clinical analysis: ADDERALL XR 15 versus METHYLIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADDERALL XR 15 versus METHYLIN.
ADDERALL XR 15 vs METHYLIN
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.
Methylphenidate is a central nervous system stimulant. It blocks the reuptake of dopamine and norepinephrine into presynaptic neurons, increasing their concentrations in the synaptic cleft.
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.
10 mg orally twice daily, administered 4-6 hours apart; doses may be adjusted in 5-10 mg increments weekly up to 60 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.
2-4 hours (short elimination half-life, requiring multiple daily dosing; immediate-release: 3-4 hours, extended-release: 3-6 hours)
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: 90% (mainly as metabolites, 30-50% as unchanged drug); fecal: <1%
Category C
Category C
CNS Stimulant
CNS Stimulant