Comparative Pharmacology
Head-to-head clinical analysis: JORNAY PM versus METHAMPEX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: JORNAY PM versus METHAMPEX.
JORNAY PM vs METHAMPEX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Methylphenidate is a central nervous system (CNS) stimulant. The mode of action in attention deficit hyperactivity disorder (ADHD) is not fully understood, but methylphenidate is thought to block the reuptake of norepinephrine and dopamine into the presynaptic neuron, increasing the levels of these neurotransmitters in the extraneuronal space.
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.
Initial: 20 mg orally once daily at bedtime; increase by 20 mg weekly as needed; max 100 mg/day.
150 mg orally twice daily for 12 weeks; alternative: 90 mg orally twice daily if tolerability issues.
None Documented
None Documented
The terminal elimination half-life of methylphenidate following JORNAY PM administration is approximately 4-5 hours. This relatively short half-life necessitates the delayed-release/extended-release formulation to provide a prolonged duration of effect.
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).
Methylphenidate and its metabolites are primarily excreted in urine (approximately 90%) as metabolites (mainly ritalinic acid) with about 2% unchanged parent drug. Fecal excretion accounts for <1%.
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