Comparative Pharmacology
Head-to-head clinical analysis: DEXEDRINE SPANSULE versus METHAMPHETAMINE HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEXEDRINE SPANSULE versus METHAMPHETAMINE HYDROCHLORIDE.
DEXEDRINE SPANSULE vs METHAMPHETAMINE HYDROCHLORIDE
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.
Methamphetamine is a potent central nervous system stimulant that increases synaptic concentrations of dopamine, norepinephrine, and serotonin by reversing their transporters, inhibiting monoamine oxidase, and inhibiting vesicular monoamine transporter 2 (VMAT2).
5-60 mg orally once daily in the morning, using extended-release capsules.
Oral: 5-10 mg once or twice daily, titrated up to a maximum of 60 mg/day in divided doses. Typical initial dose for ADHD: 5 mg once or twice daily, increase by 5 mg weekly; for obesity: 5 mg before meals, up to 30 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.
Terminal elimination half-life: 10-12 hours. Clinical context: Longer half-life than amphetamine (6-8 h) due to higher lipophilicity and tissue binding. Variability (4–30 h) depends on urine pH, dose, and chronic use (tissue accumulation).
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).
Primarily renal excretion of unchanged drug (30-50%) and metabolites (p-hydroxymethamphetamine, amphetamine, p-hydroxyamphetamine). Up to 70% eliminated over 24 hours. Renal clearance depends on urinary pH; acidic urine (pH <5) increases elimination, alkaline urine reduces it. Biliary/fecal excretion is minimal (<5%).
Category C
Category D/X
CNS Stimulant
CNS Stimulant