Comparative Pharmacology
Head-to-head clinical analysis: CONCERTA versus METHAMPHETAMINE HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CONCERTA versus METHAMPHETAMINE HYDROCHLORIDE.
CONCERTA vs METHAMPHETAMINE HYDROCHLORIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Methylphenidate is a central nervous system (CNS) stimulant. It blocks the reuptake of norepinephrine and dopamine into presynaptic neurons, increasing their levels in the synaptic cleft. It also acts as a dopamine agonist by stimulating the release of dopamine from storage sites.
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).
18-72 mg orally once daily in the morning, starting at 18-36 mg/day and titrating in 18 mg increments weekly; maximum 72 mg/day.
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 of methylphenidate from CONCERTA is approximately 3.5 hours (range 2.5-5.5 hours) in adults; in children, mean half-life is 3-4 hours. The extended-release formulation provides a prolonged clinical effect due to the OROS delivery system, not prolonged half-life.
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).
Primarily renal (77%-87% as unchanged drug and metabolites); metabolic elimination accounts for 13%-23%, with minor biliary excretion (<2%).
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