Pharmacological Differences and Clinical Implications of Vyvanse and Adderall

Mechanism and Pharmacology

Vyvanse is a prodrug that requires enzymatic conversion to active d-amphetamine in the blood, while Adderall contains immediate-release amphetamine that is active upon ingestion, according to the American Journal of Obstetrics and Gynecology 1, 2
Adderall contains a mixture of amphetamine salts (dextroamphetamine and levoamphetamine) that are pharmacologically active immediately, as noted by the American Journal of Obstetrics and Gynecology 1, 3

The American Academy of Pediatrics notes that lisdexamfetamine is more difficult to extract for misuse compared to immediate-release amphetamines 4
Adderall immediate-release formulations have higher diversion risk, particularly in adolescents, as reported by Pediatrics 5, 4
Vyvanse provides once-daily dosing with effects lasting up to 14 hours post-dose in adults, while Adderall XR also provides once-daily dosing but through different controlled-release bead technology, according to Pharmacology and Therapeutics 6, 2

The starting dose of Vyvanse is 20-30 mg once daily in the morning, with titration by 10 mg weekly, and a maximum dose of 70 mg daily, as recommended by the American Journal of Obstetrics and Gynecology 1, 3, 7
The starting dose of Adderall XR is 10 mg once daily in the morning, with titration by 5 mg weekly, and a maximum dose of 50 mg daily, according to the American Journal of Obstetrics and Gynecology 1, 3

Both medications produce similar adverse effects, including decreased appetite, sleep disturbances, increased blood pressure and heart rate, headaches, irritability, and stomach pain, as reported by Pharmacology and Therapeutics 6, 2
Both require monitoring of blood pressure, heart rate, weight, and height in children, as recommended by Pharmacology and Therapeutics and Praxis Medical Insights 2, 7

Both medications have similar safety profiles in pregnancy, with reassuring data regarding major congenital malformations, according to the American Journal of Obstetrics and Gynecology 1, 3
Both carry possible small increased risks for gastroschisis, preeclampsia, and preterm birth when used in the second half of pregnancy, as noted by the American Journal of Obstetrics and Gynecology 1, 3
Vyvanse is preferred when diversion risk is a concern because the prodrug formulation makes extraction more difficult and provides no advantage when crushed or snorted, as reported by Pediatrics 5, 4

The American Academy of Child and Adolescent Psychiatry notes that ADHD adolescents treated with stimulants show lower rates of substance use disorder than untreated ADHD adolescents 8
Parents and other family members may abuse the child's stimulant medications, and high school and college students have been reported to sell their stimulant medication or use it recreationally by crushing and snorting tablets 8
Longer-acting formulations like Adderall XR are less prone to abuse and diversion than immediate-release tablets and are more suitable for at-risk adolescents 8
The American Academy of Child and Adolescent Psychiatry recommends asking whether anyone in the household has a problem with substance abuse before prescribing, and evaluating for co-morbid psychiatric conditions that increase addiction risk 8
Prescribe extended-release formulations (Adderall XR) rather than immediate-release when diversion risk exists, and avoid sending stimulant medications to an adolescent's school to reduce diversion opportunity and peer ridicule 8
A history of stimulant abuse may not represent an absolute contraindication, but such patients require even more careful monitoring 9
The increased risk of drug abuse and cigarette smoking is associated with untreated childhood ADHD itself, not necessarily the treatment 8