Amphetamine-dextroamphetamine ER is the generic name for an extended-release stimulant medication used primarily to treat ADHD. You’ve likely seen this name on a prescription label or pharmacy bottle. The most recognized brand name is Adderall XR. The “ER” stands for extended-release, meaning the capsule is designed to work throughout the day with a single morning dose rather than requiring multiple pills.
What the Medication Contains
Each capsule contains a combination of four amphetamine salts in equal parts. The mix is specifically formulated so that the ratio of dextroamphetamine (the “dextro” or right-handed form) to levoamphetamine (the “levo” or left-handed form) is 3 to 1. These two forms of amphetamine affect the brain slightly differently. Dextroamphetamine has a stronger effect on focus and attention, while levoamphetamine contributes more to physical effects like alertness. The 3:1 blend is designed to provide a balance of both.
How the Extended-Release Capsule Works
Inside each capsule are two types of tiny beads. The first set dissolves right away, giving an initial dose shortly after you take it. The second set has a coating that delays its release by about four hours, creating a second pulse of medication later in the day. This double-pulsed delivery mimics the effect of taking two separate immediate-release tablets four hours apart, but in a single capsule. Most people experience coverage lasting roughly 10 to 12 hours.
At the brain level, the medication increases the activity of two chemical messengers: dopamine and norepinephrine. It does this partly by entering nerve cells and forcing dopamine out of its storage compartments, then making the recycling pumps on those cells work in reverse, pushing dopamine back out into the gap between neurons instead of pulling it in. The result is more dopamine and norepinephrine available in the parts of the brain responsible for attention, impulse control, and executive function.
What It’s Prescribed For
The FDA has approved amphetamine-dextroamphetamine ER for treating ADHD in adults and children 6 years and older. The immediate-release tablet version (Adderall) also carries an approval for narcolepsy, a condition involving sudden, uncontrollable episodes of sleep. The extended-release capsule, however, is indicated only for ADHD.
Typical Dosing
The medication is taken once daily in the morning. Starting doses and upper limits vary by age:
- Children 6 to 12: Usually start at 10 mg per day, with adjustments in 5 or 10 mg increments each week. The maximum recommended dose is 30 mg per day.
- Teens 13 to 17: Typically start at 10 mg per day, with an increase to 20 mg after one week if symptoms aren’t adequately controlled. Evidence hasn’t shown a clear benefit beyond 20 mg per day in this age group.
- Adults: The recommended dose is 20 mg per day. As with teens, higher doses haven’t demonstrated additional benefit in studies.
Common Side Effects
The most frequently reported side effects are decreased appetite, trouble sleeping, dry mouth, and increased heart rate. Some people also experience stomach discomfort, headaches, or feelings of nervousness and irritability. Weight loss is common, particularly in children, because the medication can significantly suppress appetite. Most of these effects are dose-dependent, meaning they tend to be more noticeable at higher doses and often improve as your body adjusts over the first few weeks.
Food and Drink Interactions
What you eat and drink around the time you take this medication can noticeably affect how well it works. A high-fat meal delays the time it takes for the drug to reach its peak level in your blood by about 2.5 hours. In one study, a heavy breakfast caused blood levels of Adderall XR to drop by 50% during the first six hours of the day. This doesn’t necessarily mean less medication gets absorbed overall, but it can shift the timing of when you feel it working.
Acidic foods and drinks present a separate concern, though this applies mainly to the immediate-release version. Fruit juice, coffee, carbonated beverages, energy drinks, sports drinks, and vitamin C supplements can reduce absorption of immediate-release amphetamine tablets. This effect is not thought to occur with the extended-release capsule formulation, but many prescribers still suggest avoiding highly acidic foods close to when you take any amphetamine product.
Safety Warnings and Legal Classification
Amphetamine-dextroamphetamine ER carries an FDA boxed warning, the most serious type of safety alert. The warning states that amphetamines have a high potential for abuse and that prolonged use may lead to dependence. It also notes that misuse can cause sudden death and serious cardiovascular events. This warning is one reason the medication is classified as a Schedule II controlled substance by the DEA, the same category as other potent stimulants.
Because of this classification, there are strict rules around how the medication is prescribed. You cannot get refills on a Schedule II prescription. Each fill requires a new prescription from your provider, and many states limit prescriptions to a 30-day supply. Your pharmacy cannot transfer the prescription to another pharmacy in most cases. These restrictions exist because Schedule II substances are considered to have a high potential for abuse that may lead to severe psychological or physical dependence.
Before starting this medication, your provider will typically ask about any history of heart problems, high blood pressure, or a family history of sudden cardiac death. Stimulants raise heart rate and blood pressure modestly in most people, which is manageable for the vast majority of patients but can pose risks for those with pre-existing cardiovascular conditions.