From the FDA Drug Label
DOSAGE AND ADMINISTRATION Amphetamines should be administered at the lowest effective dosage and dosage should be individually adjusted. Narcolepsy: Usual dose is 5 mg to 60 mg per day in divided doses, depending on the individual patient response Attention Deficit Disorder with Hyperactivity: ... Only in rare cases will it be necessary to exceed a total of 40 mg per day
The maximum dosage for Adderall (amphetamine) and Dexedrine (dextroamphetamine) is not explicitly stated for adjunct use.
- The maximum dose for Narcolepsy is 60 mg per day.
- The maximum dose for Attention Deficit Disorder with Hyperactivity is 40 mg per day, but only in rare cases should it exceed this amount. There is no information provided about the maximum dosage when using these medications together as adjunct therapy 1 2.
From the Research
The maximum recommended daily dosage for Adderall (mixed amphetamine salts) is 40mg for adults with ADHD, while Dexedrine (dextroamphetamine) has a maximum recommended daily dose of 40mg, and when used as adjunctive therapy, the combined total amphetamine dose should generally not exceed 60mg daily, divided into multiple doses. This recommendation is based on the most recent and highest quality study available, which suggests that amphetamines can be effective in reducing the severity of ADHD symptoms, but also highlights the importance of careful dosing and monitoring due to potential adverse effects 3.
Key Considerations
- The evidence from studies suggests that amphetamines, including Adderall and Dexedrine, can be effective in managing ADHD symptoms in adults, but the quality of evidence is generally low to very low due to biases and limitations in the studies 3, 4.
- The pharmacokinetics of amphetamines, including their absorption, metabolism, and elimination, play a crucial role in determining their efficacy and safety, and different formulations may offer flexibility in dosing and drug onset and offset 5.
- The use of amphetamines, especially in combination, requires careful consideration of potential risks, including cardiovascular effects, insomnia, appetite suppression, and potential for dependence, emphasizing the need for regular monitoring of vital signs, weight, sleep patterns, and mental health status 6.
- The rationale for using both Adderall and Dexedrine in adjunctive therapy relates to their slightly different pharmacokinetic profiles, which may provide smoother coverage for some patients, although evidence supporting this combination is limited 3.
Recommendations for Clinical Practice
- Patients should start with the lowest effective dose of one medication before considering adjunctive therapy, with gradual titration based on clinical response and side effects.
- Close medical supervision is essential when combining stimulant therapies to monitor for adverse effects and adjust dosages as necessary.
- Regular reassessment of the combined stimulant therapy is crucial to ensure continued necessity and effectiveness, considering the potential for adverse effects and the importance of minimizing risks while maximizing benefits.