Which medication is represented by amphetamine/dextroamphetamine 20 mg tablets?

Amphetamine/Dextroamphetamine 20 mg Tablets: Medication Identification

Amphetamine/dextroamphetamine 20 mg tablets are Adderall, a mixed amphetamine salts medication primarily prescribed for attention-deficit/hyperactivity disorder (ADHD) in both children and adults. 1, 2

Medication Composition and Formulation

• This medication contains a 3:1 ratio of dextroamphetamine to levoamphetamine salts, specifically including dextroamphetamine sulfate, dextro- and levoamphetamine sulfate, dextroamphetamine aspartate, levoamphetamine aspartate, and dextroamphetamine saccharate 2, 3

• The 20 mg dose represents a mid-range therapeutic dose, as the medication is typically titrated from 10 mg starting doses up to maximum doses of 40-50 mg daily in adults 1

Primary Clinical Indication

• Adderall is FDA-approved and most commonly prescribed for ADHD, where it reduces core symptoms of hyperactivity, impulsivity, and inattention 2, 3

• In controlled trials, this mixed amphetamine salts compound demonstrated a 42% decrease in ADHD Rating Scale scores compared to placebo, with 70% of adult patients showing clinically significant improvement (defined as >30% reduction in symptoms) versus only 7% with placebo 2

Mechanism of Action

• The medication works by enhancing dopamine and norepinephrine activity in the brain, functioning as a central nervous system stimulant 4

• Dextroamphetamine is the d-isomer of amphetamine and represents the more potent psychostimulant component of the formulation 5

Dosing Context for 20 mg Tablets

• The American College of Obstetricians and Gynecologists recommends starting adults at 10 mg once daily in the morning, with titration by 5 mg weekly increments 1

• A 20 mg dose typically represents either a single daily dose after initial titration or part of a twice-daily regimen (such as 20 mg in the morning and potentially an afternoon dose) 2

• In clinical trials, the average effective dose for adults was 54 mg daily administered in two divided doses, meaning 20 mg tablets could be used as part of this regimen 2

Duration of Action

• Standard immediate-release amphetamine/dextroamphetamine tablets (which 20 mg tablets typically are unless specified as extended-release) have a duration of action requiring twice-daily dosing to cover a full day 5, 3

• The medication has a rapid onset of action within 30 minutes for immediate-release formulations 5

Important Clinical Considerations

• The American Academy of Child and Adolescent Psychiatry emphasizes that amphetamine-based stimulants like Adderall should be avoided in patients with tic disorders or family history of tics, as amphetamines worsen tic severity more than methylphenidate alternatives 6

• Cardiovascular monitoring is essential, as daily amphetamine use increases systolic blood pressure by approximately 1.93 mmHg, diastolic blood pressure by 1.84 mmHg, and heart rate by 3.71 beats per minute 7

• Prolonged use carries cardiovascular risks including potential cardiomyopathy through mechanisms of increased oxidative stress, sympathetic overactivity, and direct myocardial toxicity 4

Common Side Effects

• The most frequently reported adverse effects include dry mouth (43% of patients), insomnia (32%), decreased appetite/anorexia (32%), headache (30%), and nervousness (26%) 8

• Withdrawal rates due to adverse effects are 2.69 times higher with amphetamines compared to placebo, with an absolute risk increase of 4.3% 7

Alternative Uses

• While ADHD is the primary indication, amphetamines including dextroamphetamine have been studied for cancer-related fatigue and HIV-related fatigue, though evidence for these uses is limited 5

• Historical uses included weight loss, though this is no longer a primary indication 7