From the Guidelines
When switching from Adderall XR 15mg to immediate release (IR) Adderall, the typical approach is to divide the extended-release dose into two daily doses of immediate release, which would be Adderall IR 7.5mg taken twice daily, with doses separated by 4-6 hours, as supported by the general principles of pharmacotherapy for ADHD 1. This conversion maintains the same total daily amphetamine exposure while changing the delivery method. The immediate release formulation will have a faster onset of action (typically 30-60 minutes) but shorter duration (4-6 hours per dose) compared to XR's 8-12 hour coverage. Some key considerations when making this switch include:
- Monitoring for changes in effectiveness, side effects, and timing of symptom control, as individual responses to the medication can vary 1.
- Being aware of the potential for increased risk of rebound effects with short-acting formulations, although this may be mitigated by the flexibility in dosing frequency and titration that IR formulations offer 1.
- Considering the potential impact on daily activities, such as avoiding sleep disruption by taking the second dose no later than mid-afternoon.
- Recognizing that both methylphenidate and amphetamine, the active ingredients in Adderall, are associated with a range of adverse effects, including decreased appetite, sleep disturbances, and increased blood pressure and pulse, which are generally mild and/or temporary but may be clinically relevant in some cases 1. It's crucial to make medication changes under medical supervision, as dosing may need adjustment based on specific needs and response, and to ensure that the switch is made safely and effectively, taking into account the individual's overall health and any potential interactions with other medications or conditions, as well as the potential risks associated with stimulant medication, such as increased heart rate and blood pressure, which may be clinically relevant for patients with preexisting cardiovascular diseases 1.
From the FDA Drug Label
CLINICAL PHARMACOLOGY ... Pharmacokinetics The pharmacokinetics of the tablet and sustained-release capsule were compared in 12 healthy subjects The extent of bioavailability of the sustained-release capsule was similar compared to the immediate-release tablet. Following administration of three 5 mg tablets, average maximal dextroamphetamine plasma concentrations (Cmax) of 36. 6 ng/mL were achieved at approximately 3 hours. Following administration of one 15 mg sustained-release capsule, maximal dextroamphetamine plasma concentrations were obtained approximately 8 hours after dosing.
The main considerations for switching from Adderall (amphetamine and dextroamphetamine) XR 15mg to immediate-release formulation are:
- Dosing schedule: The immediate-release formulation will require more frequent dosing compared to the sustained-release capsule.
- Peak plasma concentrations: The immediate-release formulation will result in higher peak plasma concentrations (Cmax) at an earlier time point (approximately 3 hours) compared to the sustained-release capsule (approximately 8 hours).
- Bioavailability: The extent of bioavailability of the sustained-release capsule is similar to the immediate-release tablet, so this is not a major consideration. 2
From the Research
Considerations for Switching from Adderall XR 15mg to Immediate-Release Formulation
- The decision to switch from Adderall XR 15mg to an immediate-release formulation should be based on individual patient needs and medical history, as stimulant medications can have varying effects on different people 3.
- When considering a switch, it is essential to evaluate the patient's response to the current medication, including any adverse events or lack of efficacy, and to assess the potential benefits and risks of the new formulation 4.
- A study comparing the bioavailability of triple-bead mixed amphetamine salts with a dose-augmentation strategy of mixed amphetamine salts extended release plus mixed amphetamine salts immediate release found that the two formulations had equivalent exposure to d- and l-amphetamine 4.
- However, the study also noted that the triple-bead formulation provided a more consistent plasma concentration over time, which may be beneficial for some patients 4.
- Another study found that switching from an immediate-release to an extended-release formulation of methylphenidate improved adherence and effectiveness in adults with attention-deficit hyperactivity disorder (ADHD) 5.
- The study suggested that the extended-release formulation may be preferred by patients due to its once-daily dosing and reduced peak-to-trough fluctuations 5.
- A bioequivalence study comparing an amphetamine extended-release oral suspension with Adderall XR found that the two formulations were bioequivalent in healthy adult volunteers 6.
- The study demonstrated that the extended-release oral suspension had a similar pharmacokinetic profile to Adderall XR, with equivalent Cmax, AUC0-5, AUC5-last, and AUCinf values for d- and l-amphetamine 6.
- When switching from Adderall XR 15mg to an immediate-release formulation, the dosage and administration schedule may need to be adjusted to achieve optimal efficacy and minimize adverse events, as the immediate-release formulation may have a shorter duration of action and more pronounced peak-to-trough fluctuations 7.