From the Guidelines
When switching from dextroamphetamine sulfate 20 mg to mixed amphetamine salts (amphetamine/dextroamphetamine), the equivalent dose would also be 20 mg. The dose remains the same because mixed amphetamine salts contain both dextroamphetamine and levoamphetamine components, with dextroamphetamine making up approximately 75% of the active ingredients. Since the therapeutic effects of these medications are primarily attributed to the dextroamphetamine component, a 1:1 conversion is typically appropriate, as suggested by the practice parameter for the use of stimulant medications in the treatment of children, adolescents, and adults 1. However, some patients may experience slight differences in effects or side effects due to the addition of levoamphetamine in the mixed formulation. It's advisable to monitor the patient after switching for any changes in therapeutic response or adverse effects, and to adjust the dose based on clinical response, as recommended in the practice parameter 1. The patient should take the medication as prescribed, typically once or twice daily depending on whether it's an immediate-release or extended-release formulation, and should be informed that while these medications are therapeutically equivalent, subtle differences in subjective effects might be noticed. Key considerations in managing the patient's treatment include:
- Using a consistent titration schedule, with dose increases in weekly increments of 5 to 10 mg per dose for MPH or 2.5 to 5 mg for DEX/AMP 1
- Deciding on a method of assessing drug response, including evaluation of target symptoms of ADHD and use of parent and teacher rating scales 1
- Managing treatment-related side effects, such as insomnia, anorexia, headaches, social withdrawal, tics, and weight loss, through systematic assessment and objective measures like weighing the patient at each visit 1
- Providing a schedule for initial titration and monitoring, with weekly contact by telephone during the titration phase, and regular follow-up appointments at least monthly during the maintenance phase 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Amphetamines should be administered at the lowest effective dosage and dosage should be individually adjusted. There is no direct information in the provided drug label to support a specific dose conversion from dextroamphetamine sulfate to amphetamine dextroamph. The FDA drug label does not answer the question.
From the Research
Dose Conversion from Dextroamphetamine Sulfate to Amphetamine Dextroamph
- The provided studies do not directly address the dose conversion from dextroamphetamine sulfate to amphetamine dextroamph 2, 3, 4, 5, 6.
- However, it is known that dextroamphetamine and amphetamine are both stimulants used to treat attention-deficit/hyperactivity disorder (ADHD), and their dosing may be related 5.
- A study on the clinical pharmacokinetics of amphetamines utilized in the treatment of ADHD discusses the various formulations of amphetamine, including immediate-release and modified-release formulations, but does not provide a direct conversion from dextroamphetamine sulfate to amphetamine dextroamph 5.
- Another study on the efficacy and safety of dextroamphetamine transdermal system for the treatment of ADHD in children and adolescents provides information on the dosing of dextroamphetamine, but not on the conversion to amphetamine dextroamph 3.
- Without direct evidence, it is not possible to provide a specific dose conversion from dextroamphetamine sulfate to amphetamine dextroamph 2, 3, 4, 5, 6.
Key Points to Consider
- Dextroamphetamine and amphetamine are both stimulants used to treat ADHD, but their dosing may be different 5.
- The clinical pharmacokinetics of amphetamines, including absorption, metabolism, and elimination, may affect the dosing of these medications 5.
- The efficacy and safety of dextroamphetamine and amphetamine formulations, including immediate-release and modified-release formulations, have been studied in various populations, including children and adolescents with ADHD 3, 5, 6.