Comparative Pharmacology
Head-to-head clinical analysis: DEXEDRINE SPANSULE versus METHYLIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEXEDRINE SPANSULE versus METHYLIN.
DEXEDRINE SPANSULE vs METHYLIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Dextroamphetamine is a central nervous system (CNS) stimulant that increases synaptic concentrations of norepinephrine and dopamine by blocking their reuptake and promoting release from presynaptic terminals.
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.
5-60 mg orally once daily in the morning, using extended-release capsules.
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
Terminal elimination half-life is 6-8 hours in adults, 10-13 hours in children, and prolonged in alkaline urine (up to 16-20 hours) due to enhanced tubular reabsorption. In hepatic impairment, half-life may extend to 12-15 hours. Steady-state is reached within 2-3 days.
2-4 hours (short elimination half-life, requiring multiple daily dosing; immediate-release: 3-4 hours, extended-release: 3-6 hours)
Renal excretion of unchanged drug (approximately 30-40% unchanged) and hepatic metabolism to inactive metabolites (primarily hippuric acid, benzoic acid, and hydroxylated derivatives). About 90% of a dose is excreted in urine within 48 hours, with 10-15% as unchanged dextroamphetamine; minor biliary/fecal elimination (<5% total).
Renal: 90% (mainly as metabolites, 30-50% as unchanged drug); fecal: <1%
Category C
Category C
CNS Stimulant
CNS Stimulant