Dextroamphetamine - Formulations - Lisdexamfetamine

Lisdexamfetamine

Dextroamphetamine is the active metabolite of the prodrug lisdexamfetamine (L-lysine-d-amphetamine), available by the trademark name Vyvanse. Lisdexamfetamine is metabolised in the gastrointestinal tract, while dextroamphetamine's metabolism is hepatic. Lisdexamfetamine is therefore an inactive compound until it is converted into an active compound by the digestive system. Although still rated as a Schedule II drug by the U.S. Drug Enforcement Administration, lisdexamfetamine has a slower onset and its route of administration is limited to being taken orally, unlike dextroamphetamine, Adderall, and methylphenidate, which can be insufflated to achieve a faster onset with a higher bioavailability. Vyvanse is marketed as once-a-day dosing as it provides a slow release of dextroamphetamine into the body. Vyvanse is available as capsules, and in six strengths; 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, and 70 mg. The conversion rate of lisdexamfetamine to dextroamphetamine base is 0.2948, thus a 30 mg-strength Vyvanse capsule is molecularly equivalent to 8.844 mg dextroamphetamine base.