- Last edited on March 26, 2023
Vyvanse® (lisdexamfetamine)
Primer
Lisdexamfetamine (Trade name: Vyvanse®) is a stimulant medication in the amphetamine class primarily used in the treatment of attention-deficit/hyperactivity disorder (ADHD). Lisdexamfetamine is a substituted amphetamine and an inactive prodrug of dextroamphetamine.
Pharmacokinetics
- Lasts 13-14 hours
Pharmacodynamics
- The drug ingested is a pro-drug (inactive product) lisdexamfetamine dimesylate (i.e. - lysine is attached to lisdexamfetamine)
- Whereas other long-acting stimulants achieve extended duration of action through “engineering,” Vyvanse achieves this through chemical conversion (hydrolysis of the covalent bond between L-lysine and d-amphetamine)
- There is no abuse potential because of this mechanism, as first-pass metabolism is the rate-limiting step.
- Lisdexamfetamine dimesylate is is converted in the serum to L-lysine (a naturally occurring amino acid) and pharmacologically active d-amphetamine
Dosing
Comparison Table
There are many different formulations of amphetamines. These are all clinically the same basic ingredient —- there are just different delivery mechanisms of each.
Different Formulations of Amphetamine Psychostimulants
Tradename | Active ingredient | Immediate/Delayed (%) | Duration | Formulations | Starting Dose | Titration | Notes |
---|---|---|---|---|---|---|---|
Adderall XR | Amphetamine mixed salts | 50/50 | 12 hours | 5, 10, 15, 20, 25, 30 mg cap | 5-10 mg q AM (adults can start at 10 mg) | • ↑ 5-10 mg at weekly intervals • Maximum dose/day: Children = 30 mg • Adolescents & Adults = 20-30 mg | • Mimics BID amphetamine dosing (one part delayed release, one part immediate release) • It lasts longer (12 hours) than Biphentin, which mimics BID methylphenidate • Capsules may be opened up and the beads inside sprinkled on soft foods (e.g. - apple sauce, yogurt, ice cream) |
Vyvanse | Lisdexamfetamine | N/A | 12-14 hours | 10, 20, 30, 40, 50, 60, 70 mg cap | 20-30 mg q AM | • ↑ 10-20 mg by clinical discretion at weekly intervals • Maximum dose/day: All ages = 60 mg | • The drug ingested is lisdexamfetamine dimesylate a pro-drug • No abuse potential because of this mechanism • Low abuse potential • Capsules may be opened up and the powder inside mixed into water (taste is slightly sweet), orange juice, or yogurt |
Dexedrine | Dextro-amphetamine | 100/0 | 4 hours | 5 mg tab | 2.5-5 mg BID | • ↑ 5 mg at weekly intervals • Maximum dose/day: (q.d. or b.i.d.) • Children & Adolescents = 20-30 mg • Adults = 50 mg | - |
Dexedrine Spansule | Dextro-amphetamine | 50/50 | Purportedly lasts 10-12 hours, but more likely 6-8 hours | 10, 15 mg cap | 10mg q AM | • ↑ 5 mg at weekly intervals • Maximum dose/day: (q.d. or b.i.d.) • Children & Adolescents = 20-30 mg • Adults = 50 mg | • Essentially mimics BID dexedrine tabs • Capsule containing 2 kinds of beads (50% d-amphetamine, 50% polymer-coated d-amphetamine) • Capsules may be opened up and the beads inside sprinkled on soft foods |
Psychosis Risk
Dextroamphetamine
Indications
- Binge-Eating Disorder (moderate to severe)
- The dose range for BED is slightly higher than for ADHD
Pearls
- Capsules may be opened up and the powder inside (taste is slightly sweet) can be mixed into water, orange juice, or yogurt.