What is the proper usage and dosage of Dexamfetamine (Dextroamphetamine) for conditions like Attention Deficit Hyperactivity Disorder (ADHD) and narcolepsy?

From the Guidelines

Dexamfetamine (Dextroamphetamine) should be prescribed at different dosages depending on the condition being treated and the patient's age, with careful monitoring of side effects and regular assessment of treatment response, as recommended by the most recent and highest quality study 1.

Key Considerations for Dexamfetamine Prescription

• For ADHD in adults, treatment usually begins with 5mg once or twice daily, gradually increasing if needed to an effective dose, typically 20-40mg daily divided into multiple doses.
• For children with ADHD (6 years and older), starting doses are lower, usually 2.5-5mg daily, increasing gradually to 20-30mg daily divided into doses.
• For narcolepsy, adults typically start with 10mg daily, increasing by 10mg increments to an effective dose, usually 40-60mg daily divided into doses.

Important Administration Guidelines

• The medication should be taken in the morning and early afternoon to avoid sleep disturbances, with the last dose typically at least 6 hours before bedtime.
• Dexamfetamine works by increasing levels of dopamine and norepinephrine in the brain, improving attention, focus, and wakefulness.

Monitoring and Side Effects

• Regular monitoring by a healthcare provider is essential to assess effectiveness and manage potential side effects such as increased heart rate, blood pressure, decreased appetite, and insomnia.
• The medication should be taken exactly as prescribed, as it has potential for dependence and misuse, as noted in studies 1.

Decision-Making Factors

• The choice of medication and dosing regimen can affect medication adherence, with once-daily dosing generally preferred over twice-daily dosing 1.
• Factors such as attitudes of patients and parents toward pharmacological treatment, a trustful physician-patient relationship, family support, and knowledge about the disorder and the intended medication should be evaluated and improved if possible to increase medication adherence 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Amphetamines should be administered at the lowest effective dosage and dosage should be individually adjusted. Late evening doses should be avoided because of the resulting insomnia. Narcolepsy: Usual dose is 5 mg to 60 mg per day in divided doses, depending on the individual patient response Narcolepsy seldom occurs in pediatric patients under 12 years of age; however, when it does, dextroamphetamine sulfate tablets may be used. The suggested initial dose for patients aged 6 to 12 is 5 mg daily; daily dose may be raised in increments of 5 mg at weekly intervals until optimal response is obtained In patients 12 years of age and older, start with 10 mg daily; daily dosage may be raised in increments of 10 mg at weekly intervals until an optimal response is obtained. If bothersome adverse reactions appear (e.g., insomnia or anorexia), dosage should be reduced. Give first dose on awakening; additional doses (1 or 2) at intervals of 4 to 6 hours. Attention Deficit Disorder with Hyperactivity: Not recommended for pediatric patients under 3 years of age. In pediatric patients from 3 to 5 years of age, start with 2.5 mg daily, by tablet; daily dosage may be raised in increments of 2. 5 mg at weekly intervals until optimal response is obtained. In pediatric patients 6 years of age and older, start with 5 mg once or twice daily; daily dosage may be raised in increments of 5 mg at weekly intervals until optimal response is obtained. Only in rare cases will it he necessary to exceed a total of 40 mg per day Give first dose on awakening: additional doses (1 or 2) at intervals of 4 to 6 hours. Where possible, drug administration should be interrupted occasionally to determine if there is a recurrence of behavioral symptoms sufficient to require continued therapy.

The proper usage and dosage of Dexamfetamine (Dextroamphetamine) for conditions like Attention Deficit Hyperactivity Disorder (ADHD) and narcolepsy are as follows:

• For narcolepsy:
  • Patients aged 6 to 12: start with 5 mg daily, increase by 5 mg at weekly intervals
  • Patients 12 years of age and older: start with 10 mg daily, increase by 10 mg at weekly intervals
• For ADHD:
  • Pediatric patients from 3 to 5 years of age: start with 2.5 mg daily, increase by 2.5 mg at weekly intervals
  • Pediatric patients 6 years of age and older: start with 5 mg once or twice daily, increase by 5 mg at weekly intervals
  • Do not exceed 40 mg per day, except in rare cases The dosage should be administered at the lowest effective dosage and adjusted individually, with the first dose given on awakening and additional doses at intervals of 4 to 6 hours 2.

From the Research

Proper Usage and Dosage of Dexamfetamine

The proper usage and dosage of Dexamfetamine (Dextroamphetamine) for conditions like Attention Deficit Hyperactivity Disorder (ADHD) and narcolepsy can be understood through various studies.

• Dexamfetamine is used to treat adults with ADHD, but uncertainties about its efficacy and safety remain 3.
• The dosage of Dexamfetamine for ADHD can range from 10.2 mg/d to 21.8 mg/d, with studies showing that amphetamines can reduce the severity of ADHD symptoms as rated by clinicians and patients 3.
• However, the evidence for Dexamfetamine's efficacy in reducing ADHD symptoms is of low to very low quality, and it is associated with an increased proportion of patients who withdraw due to adverse events 3.

Comparison with Other Amphetamines

• Different amphetamine compositions, such as lisdexamfetamine and mixed amphetamine salts, have been shown to be efficacious in reducing ADHD symptoms, with varying pharmacological and pharmacokinetic profiles 4, 5.
• Lisdexamfetamine, a prodrug of Dexamfetamine, has been shown to have reduced abuse liability compared to short-acting amphetamine compositions 4, 5.
• The clinical pharmacokinetics of amphetamines, including Dexamfetamine, have been reviewed, highlighting the importance of understanding absorption, metabolism, and elimination in the treatment of ADHD 6.

Pharmacology and Mechanisms of Action

• Amphetamine and methylphenidate, both psychostimulants, have different pharmacological effects and mechanisms of action, which can impact their use in managing individuals with ADHD and comorbid psychiatric conditions 7.
• Amphetamine's actions include dopamine and norepinephrine transporter inhibition, vesicular monoamine transporter 2 (VMAT-2) inhibition, and monoamine oxidase activity inhibition, which can increase central dopamine and norepinephrine activity 7.
• Understanding the pharmacology and mechanisms of action of Dexamfetamine and other amphetamines can help physicians make informed decisions about their use in the treatment of ADHD and other conditions 7.