Comparative Pharmacology
Head-to-head clinical analysis: BENZEDRINE versus JORNAY PM.
Head-to-head clinical analysis: BENZEDRINE versus JORNAY PM.
BENZEDRINE vs JORNAY PM
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. 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.
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.
Initial: 20 mg orally once daily at bedtime; increase by 20 mg weekly as needed; max 100 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.
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.
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.
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%.
Category C
Category C
CNS Stimulant
CNS Stimulant