Adderall XR: What to Expect, Week-by-Week First Month

Week 1: The First Capsule

Adderall XR is taken once daily on awakening, and the label says to avoid afternoon doses [1]. Each capsule contains two bead types, one immediate-release and one delayed-release, that prolong the release of the four amphetamine salts [1]. One 20 mg capsule produces a blood-level curve close to immediate-release Adderall 10 mg taken twice, four hours apart [1].

Blood levels peak about 7 hours after a dose, roughly 4 hours later than immediate-release Adderall tablets, which peak about 3 hours after a dose [3][1]. Food does not change how much is absorbed, but it delays the peak by about 2.5 hours: after a 30 mg dose the d-amphetamine peak moved from 5.2 to 7.7 hours [1].

The adult trial reported ADHD improvement in the first week [2]. The most frequent adverse reactions in the label's adult trial were dry mouth, reported by 35% of people on Adderall XR versus 5% on placebo, and loss of appetite, 33% versus 3% [1]. Insomnia was reported by 27% versus 13% in adults and by 17% versus 2% in children aged 6 to 12 in a three-week trial [1][4]. These are rates across each whole trial, so they do not show which week a reaction began.

Weeks 2 and 3: Dose Changes

The label lists a 20 mg daily dose for adults [1]. For children aged 6 to 12 it lists a start of 10 mg, or 5 mg if a lower start is judged appropriate, with increases of 5 or 10 mg at weekly intervals up to 30 mg a day; adolescents aged 13 to 17 start at 10 mg and may increase to 20 mg after a week [1].

Someone already taking divided immediate-release doses can switch to Adderall XR at the same total daily dose, taken once [1]. In severe renal impairment the starting dose is 15 mg for adults and 5 mg for children and adolescents, with a 20 mg maximum for ages 6 to 12, and Adderall XR is not recommended in end-stage renal disease [1].

The adult trial randomized 255 people to 20, 40 or 60 mg a day or placebo for four weeks. Every dose group improved significantly on the ADHD Rating Scale (mean endpoint scores 18.5, 18.4 and 18.5), the mean effect size was 0.8, and the trial reported a 12-hour duration of effect [2].

Adverse Reactions Reported During Treatment

In adults, headache was reported by 26% versus 13% on placebo, weight loss by 10% versus 0%, anxiety by 8% versus 5%, dizziness by 7% versus 0% and tachycardia by 6% versus 3% [1]. Children aged 6 to 12 reported abdominal pain at 14% versus 10% and emotional lability at 9% versus 2% [1]. Adolescents aged 13 to 17 reported loss of appetite at 36% versus 2% and weight loss at 9% versus 0% [1].

Growth is the pediatric-specific concern. The Adderall immediate-release label states that CNS stimulants have been associated with weight loss and slowed growth in children and that height and weight should be closely monitored [3], and a review of longitudinal studies found a modest reduction in expected height and weight that attenuated over time [5].

Children also clear amphetamine faster per kilogram than adults [1]. Mean d-amphetamine half-life is about 9 hours in children aged 6 to 12, 11 hours in adolescents and 10 hours in adults; for l-amphetamine it is about 11 hours in children and 13 hours in adults [1].

Week 4: What the Four-Week Adult Trial Showed

The adult trial ended at four weeks and found improved ADHD rating scores in each Adderall XR dose group [2]. That result is a group average at the end of the trial and does not set a deadline for judging an individual's dose.

For context on what a stimulant is expected to do over roughly 12 weeks, a network meta-analysis of 133 double-blind trials found amphetamines (a group that included lisdexamfetamine) reduced clinician-rated ADHD symptoms more than placebo, with a standardized mean difference of -1.02 in children and adolescents and -0.79 in adults, and more than methylphenidate in head-to-head comparisons; dropout because of side effects was higher than with placebo (odds ratio 2.30 in children and adolescents, 3.26 in adults) [6]. Data were insufficient for 26- and 52-week comparisons [6].

The Boxed Warning

Adderall XR carries a boxed warning for abuse, misuse and addiction [1]. The Adderall tablet label's boxed warning says the drug has a high potential for abuse and misuse, which can lead to a substance use disorder including addiction, and that misuse and abuse can lead to overdose or death, especially at higher doses or with unapproved methods of use such as snorting or injection [3]. It also directs prescribers to assess each person's risk before prescribing, to educate patients and families about proper storage and disposal, and to reassess risk and monitor throughout treatment [3].

New psychosis in young people is uncommon but measurable. In an observational insurance-claims study of patients aged 13 to 25 with ADHD, a new psychosis diagnosis with an antipsychotic prescription within 60 days occurred in 0.21% of 110,923 matched amphetamine users versus 0.10% of 110,923 methylphenidate users, a hazard ratio of 1.65 [7].

The Adderall tablet label says CNS stimulants as a class raise blood pressure by a mean of about 2 to 4 mm Hg and heart rate by about 3 to 6 bpm, with larger rises in some patients [3].

Products That Are Not Adderall XR

Adderall XR is approved for ADHD in adults and children aged 6 and older, not for narcolepsy, and it is not recommended under age 6, where plasma exposure is higher and adverse reactions such as weight loss are more common [1]. Immediate-release Adderall tablets are approved for ADHD, with dosing from age 3, and for narcolepsy [3]. Mydayis is a different triple-bead capsule for ages 13 and older whose effects may last up to 16 hours, and it is not substituted milligram for milligram for other amphetamine products [8].