Generic Name

Vyvanse

Mechanism

• Prodrug activation: Oral Vyvanse is hydrolyzed by red‑blood‑cell and plasma enzymes to release free dextro‑amphetamine.
• Neurotransmitter effects:
• Blocks presynaptic dopamine and norepinephrine transporters (DAT & NET), increasing synaptic concentrations.
• Enhances release of dopamine and norepinephrine via σ‑1 receptor interaction.
• Clinical outcome: Augmented dopaminergic and noradrenergic tone improves attention, executive function, and inhibitory control.

Pharmacokinetics

• Absorption: Rapid, with peak plasma levels at ~1‑1.5 h after dosage. Bioavailability of amphetamine ~20 % of the prodrug dose.
• Distribution: Extensive (∼75 % protein binding); crosses the blood‑brain barrier.
• Metabolism: Hydrolytic conversion to dextroamphetamine, primarily via plasma and erythrocyte enzymes; minimal hepatic CYP involvement.
• Elimination: Renal excretion of unchanged amphetamine and metabolites.
• Half‑life: ~12 h (consistent, dose‑linear).
• Drug interactions: Weak CYP1A2 inhibition (minimal). Strongly inhibit CYP1A2; caution with fluvoxamine, ciprofloxacin.

Indications

• ADHD in children (6 yrs+) and adults.
• Binge‑Eating Disorder (BED) in adults (≥18 yrs).

Contraindications

• Contraindications:
• Known cardiac disease (e.g., obstructive coronary artery disease, uncontrolled arrhythmia).
• Severe hypertension.
• Thyrotoxicosis, hyperthyroidism.
• Ingestion of acidic beverages <30 min post‑dose.
• Warnings:
• Cardiovascular: Tachycardia, hypertension, ischemia.
• Psychiatric: Suicidal ideation, psychosis, mania.
• Growth suppression: Monitor height/weight in pediatric patients.
• Abuse potential: Prodrug design reduces but does not eliminate risk; vigilance for diversion.

Dosing

• Method: Whole capsule taken orally once daily, preferably in the morning; avoid splitting capsules.
• Adjustments: Titrate based on therapeutic response and tolerability; consider weight‑based dosing in pediatrics.

Adverse Effects

Common (≥10 %)
• Dry mouth
• Insomnia / sleep disturbance
• Decreased appetite / weight loss
• Headache
• Irritability

Serious (≤1 %)
• Cardiovascular: hypertension, tachycardia, ischemic events.
• Psychiatric: mania, psychosis, suicidal ideation.
• Growth impairment in children (shorter stature).
• Severe allergic reactions (rare).

Monitoring

• Baseline & Follow‑up: Blood pressure, heart rate, weight/height (peds), growth.
• Cardiac monitoring: ECG if history of arrhythmia/structural heart disease.
• Laboratory: Routine labs are not mandatory, but metabolic panels if psychiatric comorbidity.
• Efficacy markers: ADHD rating scales; behavioral observations for BED.
• Safety: Screen for substance use; document dosing adherence; assess for suicidal thoughts.

Clinical Pearls

• Prodrug advantage: Hydrolysis in blood reduces peak plasma concentration spikes, lowering abuse potential and easing side‑effect management.
• Timing of ingestion: Take one hour before activities requiring alertness; avoid immediately after acidic drinks (e.g., orange juice) to prevent delayed release.
• Dose escalation: Increment only after at least 1‑2 weeks; rapid stepping can precipitate tachycardia.
• Pediatric growth: Track height/weight quarterly; consider temporary discontinuation if growth suppression persists.
• Interaction with cimetidine: Possible increase in amphetamine exposure; monitor blood pressure.
• Re‑induction after discontinuation: Start at 30 mg even if previously higher; taper cautiously to minimize rebound hyperactive symptoms.
• Compliance strategy: Use pill organizers; educate caregivers on dose timing relative to meals.

--
• *This drug card provides concise, evidence‐based information for medical students and healthcare professionals. For detailed prescribing information, consult the FDA label and local guidelines.*