Dexamfetamine
The dextrorotatory enantiomer of amphetamine, marketed as Dexedrine, used for ADHD and narcolepsy. It releases dopamine and noradrenaline and blocks their reuptake, giving potent stimulant effects. Well characterised over decades, with meaningful dependence, cardiovascular and appetite/sleep trade-offs.
01 Overview
Dexamfetamine (dextroamphetamine) is a long-established stimulant with robust evidence in ADHD and narcolepsy. It is more potent than methylphenidate on a per-milligram basis and is a component of mixed amphetamine salts (Adderall).
It is Schedule II in the US, reflecting recognised abuse liability. Therapeutic use is generally safe under supervision, but appetite suppression, insomnia, cardiovascular stimulation and psychological dependence are well documented, and high-dose or non-medical use raises the risk of psychosis and cardiovascular events.
02 Mechanism
Enters monoaminergic neurons via transporters and displaces dopamine and noradrenaline from vesicles into the synapse, while also inhibiting reuptake and MAO, sharply raising catecholamine levels.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Therapeutic (adult ADHD) | 5–40 mg/day | Oral | Titrated from 5-10 mg/day; often split into 2-3 doses or given as spansule. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Improved attention and reduced hyperactivityAmphetamines show the largest effect sizes among ADHD medications in adults. | Large effect size in ADHD | Clinical | |
| Increased wakefulnessReduces excessive daytime sleepiness in narcolepsy. | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Appetite suppressionMarked reduction in appetite, with weight loss and growth effects in children. | Moderate | Very common | Clinical | |
| Insomnia and cardiovascular stimulationDelayed sleep and raised heart rate/blood pressure. | Moderate | Common | Clinical | |
| Dependence and abusePsychological dependence and tolerance can develop, especially with escalating or non-prescribed use. | Severe | Common with misuse | Clinical |