Comparative Pharmacology
Head-to-head clinical analysis: DEXAMPEX versus METHAMPEX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEXAMPEX versus METHAMPEX.
DEXAMPEX vs METHAMPEX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Dextroamphetamine is a central nervous system stimulant that increases extracellular dopamine and norepinephrine levels by blocking their reuptake and promoting release from presynaptic terminals.
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.
5-10 mg orally once daily in the morning, maximum 20 mg/day.
150 mg orally twice daily for 12 weeks; alternative: 90 mg orally twice daily if tolerability issues.
None Documented
None Documented
Terminal elimination half-life 10–13 hours in adults (7–8 hours in children). Longer in alkaline urine (up to 20 hours) due to reduced renal tubular reabsorption.
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: ~90% as unchanged drug and metabolites (primarily deaminated metabolites); fecal/biliary <2%.
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