Comparative Pharmacology
Head-to-head clinical analysis: ADDERALL XR 30 versus METHYLIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADDERALL XR 30 versus METHYLIN.
ADDERALL XR 30 vs METHYLIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Adderall XR is a central nervous system (CNS) stimulant. It contains a mixture of amphetamine salts (dextroamphetamine and levoamphetamine). Amphetamines are non-catecholamine sympathomimetic amines that promote release of catecholamines (primarily dopamine and norepinephrine) from presynaptic nerve terminals and inhibit their reuptake, leading to increased synaptic concentrations. The exact mechanism of action in attention deficit hyperactivity disorder (ADHD) is not fully understood but is thought to involve activation of dopaminergic and noradrenergic pathways in the prefrontal cortex.
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.
20-60 mg orally once daily in the morning; start at 20 mg once daily, titrate by 10 mg weekly based on tolerability and response.
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 is 10–13 hours for dextroamphetamine (the more active enantiomer) in adults; for the racemic mixture (dextroamphetamine/amphetamine), the half-life is shorter (6–8 hours) due to differential metabolism. Clinical context: Steady-state achieved within 2–3 days; once-daily dosing is sufficient.
2-4 hours (short elimination half-life, requiring multiple daily dosing; immediate-release: 3-4 hours, extended-release: 3-6 hours)
Renal: approximately 90% (30–40% unchanged, remainder as metabolites including dehydroamphetamine and hydroxylated metabolites). Fecal: <4%. Biliary: minimal.
Renal: 90% (mainly as metabolites, 30-50% as unchanged drug); fecal: <1%
Category C
Category C
CNS Stimulant
CNS Stimulant