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Dextroamphetamine

Dextroamphetamine

Dexedrine ProCentra Zenzedi Dextrostat

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Updated: December 06, 2025

Overview

Dextroamphetamine is a central nervous system (CNS) stimulant primarily used to treat attention deficit hyperactivity disorder (ADHD) and narcolepsy. It belongs to the amphetamine class and works by increasing the levels of certain neurotransmitters in the brain, particularly dopamine and norepinephrine, which help improve focus, attention, and impulse control. As a Schedule II controlled substance, dextroamphetamine has a high potential for abuse and dependence. It is available in immediate-release and extended-release formulations, with careful dose titration required to balance therapeutic benefits and adverse effects. Clinical use requires monitoring for cardiovascular and psychiatric risks.

Drug Class

Central nervous system stimulant, Amphetamine, Sympathomimetic amine

Mechanism of Action

Dextroamphetamine exerts its effects by: • Increasing dopamine and norepinephrine release from presynaptic neurons • Inhibiting monoamine reuptake transporters (DAT, NET) • Blocking vesicular monoamine transporter 2 (VMAT2), increasing cytoplasmic neurotransmitter levels • Weakly inhibiting monoamine oxidase (MAO) These actions enhance neurotransmission in cortical and subcortical regions, improving attention and alertness.

Pharmacokinetics

Absorption: Well-absorbed orally (75-100% bioavailability), unaffected by food Distribution: Widely distributed, crosses blood-brain barrier, protein binding ~15-40% Metabolism: Hepatic via CYP2D6 to active metabolites (e.g., hydroxyamphetamine) Excretion: Primarily renal (30-40% unchanged), pH-dependent excretion (acidic urine increases elimination) Half-life: 10-12 hours (immediate-release), 11-15 hours (extended-release)

Pharmacodynamics

Effects on body systems: • CNS: Increased alertness, improved concentration, reduced fatigue • Cardiovascular: Increased heart rate, blood pressure • Metabolic: Appetite suppression, potential weight loss • Endocrine: Mild increases in cortisol and growth hormone

Indications

• Attention Deficit Hyperactivity Disorder (ADHD): Improves focus and reduces impulsivity/hyperactivity in children ≥3 years and adults • Narcolepsy: Promotes wakefulness in patients with excessive daytime sleepiness • Off-label: Treatment-resistant depression (adjunct), cognitive enhancement in traumatic brain injury

Contraindications

Absolute: • Concurrent MAOI use or within 14 days • Advanced arteriosclerosis • Symptomatic cardiovascular disease • Hyperthyroidism • Glaucoma Relative: • Moderate hypertension • Anxiety disorders • History of substance use disorder • Tourette's syndrome

Dosage & Administration

ADHD (children 3-5 years): Start 2.5 mg daily, increase by 2.5 mg weekly (max 40 mg/day) ADHD (≥6 years and adults): Start 5 mg 1-2x daily, increase by 5 mg weekly (max 40 mg/day) Narcolepsy: 5-60 mg/day in divided doses Extended-release formulations: Administer once daily in morning

Special Populations

Pediatric: Monitor growth parameters closely Geriatric: Use lower doses due to increased cardiovascular risk Renal impairment: Reduce dose in severe impairment (CrCl <30 mL/min) Hepatic impairment: Use with caution, consider dose reduction

Adverse Effects

Common (>10%): • Insomnia • Decreased appetite • Dry mouth • Headache • Weight loss Serious (<1%): • Cardiovascular events (MI, stroke) • Psychosis • Seizures • Peripheral vasculopathy • Serotonin syndrome

Drug Interactions

• MAOIs: Risk of hypertensive crisis • SSRIs/SNRIs: Increased serotonin effects • Alkalinizing agents (e.g., sodium bicarbonate): Increased amphetamine absorption • Acidifying agents (e.g., vitamin C): Decreased amphetamine efficacy • Antihypertensives: Reduced hypotensive effects

Warnings & Precautions

• High abuse potential (Schedule II controlled substance) • May exacerbate psychiatric disorders • Risk of sudden death in patients with structural cardiac abnormalities • Potential for growth suppression in children • Peripheral vasculopathy (Raynaud's phenomenon) • Serotonin syndrome risk when combined with serotonergic drugs

Pregnancy & Lactation

Pregnancy: FDA Category C - Risk cannot be ruled out. Use only if potential benefit justifies risk. Lactation: Contraindicated - Excreted in breast milk, may cause infant irritability and sleep disturbances.

Monitoring Parameters

• Blood pressure and heart rate at baseline and regularly • Height/weight in pediatric patients • Psychiatric symptoms • Signs of misuse/diversion • CBC, electrolytes in long-term use

Patient Counseling

• Take exactly as prescribed; do not crush/extend-release tablets • Avoid late afternoon/evening doses to prevent insomnia • Report chest pain, palpitations, or mood changes • Do not share medication • Store securely to prevent misuse • Gradual taper needed for discontinuation

Storage & Stability

Store at 20-25°C (68-77°F) in tight, light-resistant container. Protect from moisture. Dispense in original container with child-resistant closure.

Clinical Pearls

• Check cardiac history before prescribing • Consider drug holidays in pediatric patients to assess need • Use validated ADHD rating scales for monitoring • Extended-release formulations reduce abuse potential • Screen for family history of sudden cardiac death

References

• Goodman & Gilman's: The Pharmacological Basis of Therapeutics, 14th ed • Dexedrine Prescribing Information, FDA • Micromedex DrugDex Evaluation: Dextroamphetamine • NICE Guidelines: ADHD Diagnosis and Management