Comparative Pharmacology
Head-to-head clinical analysis: BENZEDRINE versus CONCERTA.
Head-to-head clinical analysis: BENZEDRINE versus CONCERTA.
BENZEDRINE vs CONCERTA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Benzedrine (racemic amphetamine) releases dopamine and norepinephrine from presynaptic neurons, blocks their reuptake, and inhibits monoamine oxidase, increasing synaptic monoamine levels.
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.
Oral: 5-10 mg once or twice daily, maximum 40 mg/day. Intramuscular: 5-10 mg every 30-60 minutes as needed, maximum 40 mg/day.
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.
None Documented
None Documented
Terminal elimination half-life: 4-6 hours in adults (range 4-8 hours). Clinically, duration of action correlates with half-life, but tolerance may develop with repeated dosing.
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.
Renal (30-40% unchanged, pH-dependent), with minor biliary/fecal elimination. At acidic urine pH, elimination half-life is shortened; at alkaline pH, reabsorption increases.
Primarily renal (77%-87% as unchanged drug and metabolites); metabolic elimination accounts for 13%-23%, with minor biliary excretion (<2%).
Category C
Category C
CNS Stimulant
CNS Stimulant