From the Guidelines
I strongly advise against self-converting between stimulant medications, and instead, recommend consulting a qualified healthcare provider to determine the appropriate equivalent dose of Methylphenidate (Ritalin) for someone transitioning from 40mg of Amphetamine (Adderall) and 70mg of Lisdexamfetamine (Vyvanse).
Key Considerations
- Medication conversions between different stimulants must be individualized, taking into account a patient's specific medical history, body weight, metabolism, and response to medications 1.
- The provided study does not offer a direct conversion guide between these medications, highlighting the complexity of such conversions 1.
- Stimulants like methylphenidate/Ritalin, amphetamine/Adderall, and lisdexamfetamine/Vyvanse have distinct mechanisms, potencies, durations, and side effect profiles, making self-conversion risky 1.
Risks of Self-Conversion
- Inappropriate dosing could lead to serious side effects, such as cardiovascular issues, psychiatric problems, or other adverse reactions 1.
- Inadequate treatment may result from underdosing, potentially leading to a lack of symptom control and decreased quality of life.
Recommended Approach
- Schedule an appointment with your prescribing physician to safely determine the appropriate starting dose of Methylphenidate (Ritalin) based on your medical history and current medication regimen.
- Your healthcare provider may start with a lower dose and gradually increase it while monitoring for effectiveness and side effects 1.
Importance of Medical Supervision
- Never adjust stimulant medications without medical supervision to avoid potential complications and ensure the best possible outcome in terms of morbidity, mortality, and quality of life.
From the Research
Equivalent Dose of Methylphenidate
To determine the equivalent dose of Methylphenidate (Ritalin) for someone transitioning from 40mg of Amphetamine (Adderall) and 70mg of Lisdexamfetamine (Vyvanse), we need to consider the pharmacological properties of these medications.
- Methylphenidate and amphetamine salts are the stimulant drugs of choice for ADHD treatment, with Methylphenidate inhibiting the reuptake of dopamine and norepinephrine, similar to amphetamines 2.
- Lisdexamfetamine is a prodrug of dextroamphetamine, with low feasibility for abuse 2, 3.
- The efficacy and safety of medications for attention-deficit hyperactivity disorder (ADHD) have been compared in several studies, including a systematic review and network meta-analysis that estimated the comparative efficacy and tolerability of oral medications for ADHD in children, adolescents, and adults 4.
Dose Conversion
However, there is no direct evidence in the provided studies to support a specific dose conversion from Amphetamine (Adderall) and Lisdexamfetamine (Vyvanse) to Methylphenidate (Ritalin).
- A study on the transition from methylphenidate or amphetamine to atomoxetine in children and adolescents with ADHD found that patients were successfully switched from methylphenidate or amphetamine to atomoxetine treatment, with resulting improvement in ADHD symptom severity from baseline 5.
- Another study compared the efficacy and safety of mixed amphetamine salts extended release (Adderall XR) in the management of ADHD in adolescent patients, but did not provide information on dose conversion to Methylphenidate (Ritalin) 6.
Limitations
The provided studies do not offer a clear equivalent dose of Methylphenidate (Ritalin) for someone transitioning from 40mg of Amphetamine (Adderall) and 70mg of Lisdexamfetamine (Vyvanse).