Comparative Pharmacology
Head-to-head clinical analysis: ADDERALL XR 5 versus METHAMPEX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADDERALL XR 5 versus METHAMPEX.
ADDERALL XR 5 vs METHAMPEX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Adderall XR 5 contains a combination of amphetamine and dextroamphetamine, which are central nervous system stimulants. They increase the levels of dopamine and norepinephrine in the synaptic cleft by inhibiting their reuptake and promoting their release from presynaptic neurons.
Methamphetamine is a sympathomimetic amine that increases synaptic concentrations of dopamine, norepinephrine, and serotonin by promoting their release from presynaptic terminals and inhibiting their reuptake. It also inhibits monoamine oxidase, reducing neurotransmitter catabolism.
20 mg orally once daily in the morning
150 mg orally twice daily for 12 weeks; alternative: 90 mg orally twice daily if tolerability issues.
None Documented
None Documented
d-Amphetamine: 10-13 hours (adults), 11-14 hours (children); l-Amphetamine: 13-15 hours (adults). The prolonged terminal half-life of the extended-release formulation supports once-daily dosing.
Terminal elimination half-life is approximately 9-14 hours in adults with normal renal function (mean ~12 hours). In children, half-life is shorter (~8-10 hours). Context: Steady-state is achieved within 2-3 days. Half-life may be prolonged in patients with renal impairment (up to 20-30 hours) or alkaline urine (up to 30 hours).
Renal (approximately 90% as unchanged drug and metabolites, with 30-40% as unchanged amphetamine), fecal (minimal, <5%)
Primarily renal excretion (≥90% as unchanged drug and metabolites); approximately 70-80% as unchanged amphetamine, 10-15% as deaminated metabolites (hippuric acid, benzoic acid). Biliary/fecal excretion is negligible (<5%). Renal clearance is pH-dependent; acidic urine increases elimination. In overdose or renal impairment, elimination half-life may prolong.
Category C
Category C
CNS Stimulant
CNS Stimulant