Xelstrym (dextroamphetamine) transdermal system is the first and only available amphetamine patch, FDA-approved in March 2022 for treatment of ADHD in ages 6+.
Visual mnemonic: “Zelda strums”
Mnemonic for amphetamine product: amp
Mnemonic for CYP2D6 substrate: beach ball
❖ Amphetamine stimulant
❖ DA > NE reuptake inhibitor
❖ DA > NE releaser
❖ DEA Schedule II
Available strengths:
4.5 mg / 9 hr
9 mg / 9 hr
13.5 mg / 9 hr
18 mg / 9 hr
The patch should be applied 2 hours before an effect is needed. It is worn for 9 hours on the hip, upper arm, chest, upper back, or flank.
Transdermal delivery allows the patient to determine duration of effect. The main disadvantage is the 2-hour delay in onset.
Adverse effects at the application site were about twice as likely than with placebo patch. Localized dermal complaints included irritation (94%), discomfort (69%), pain (13%), severe discomfort (10%), and pruritus (7%). Refer to pages 218–219 of Cafer's Psychopharmacology for general information about stimulants, with risks and warnings.
Dynamic interactions:
❖ CNS stimulant
❖ Hypertensive effects
❖ Lowers seizure threshold
❖ Serotonergic (mild)
Kinetic interactions:
❖ 2D6 substrate (minor)
❖ Reduced excretion in alkaline urine, e.g., caused by acetazolamide (Diamox) can potentially lead to amphetamine toxicity
Check out Cafer's Psychopharmacology: Visualize to Memorize 270 Medication Mascots for a visual mnemonic system for generic/trade name pairings, drug-drug interactions, and remembering which of the numerous available stimulant products are methylphenidates vs amphetamines.
Amphetamine product | Approx duration | Formulation | Notes |
Adderall (mixed amphetamine salts) | 5 hr | Capsule | 75% D- and 25% L- amphetamine isomers |
Adderall XR | 10 hr | Capsule (can sprinkle) | Half is immediate release |
Adzenys XR-ODT | 10 hr | Orally disintegrating tablet (ODT) | [add ZEN iss] |
Mydayis | 16 hr | Capsule (can sprinkle) | pH-dependent release |
Vyvanse (lisdexamfetamine) | 10-14 hr | Capsule (can dissolve contents) | Prodrug converted to 100% D-amphetamine in RBCs. OK that it's powder because effect is no faster if snorted. |
Dexedrine | 4 hr | Capsule (can sprinkle) | 100% D-amphetamine |
Evekeo (formerly Benzedrine) | 4 hr | Splittable tablet | 50% D- and 50% L- isomers |
Desoxyn (methamphetamine) | 4 hr | Splittable tablet | It’s legal methamphetamine, very rarely prescribed |
Dyanavel XR | 10 hr | Liquid | [dy ANN a vel] 3.2 to 1 D- to L-amphetamine ratio |
Xelstrym (transdermal) | 9 hr | Patch | Apply 2 hours prior to needed effect |