Amphetamine

Amphetamines (Trade names: Adderall, Vyvanse, Dexedrine) are a class of medications that stimulate release of dopamine and, to a lesser extent, norepinephrine from presynaptic sites in neurons. It is used in the treatment of attention-deficit/hyperactivity disorder.

Amphetamines bind to monoamine (serotonin, dopamine, and norepinephrine) transporters (SERT, DAT, NET) and increase extracellular levels of monoamines including dopamine, noradrenaline (norepinephrine) and serotonin. Amphetamines also provoke the release of norepinephrine and dopamine through the inhibition of vesicular monoamine transporter 2 (VMAT2) from presynaptic neurons.[1] The increase in dopamine are thought to improve attention and reduce distractibility in ADHD. Amphetamine also inhibits the metabolism of monoamine neurotransmitters by inhibiting monoamine oxidase (MAO).

There are many different formulations of methylphenidate. These medications 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