At a Glance
Oral amphetamine is FDA-approved to treat attention-deficit/hyperactivity disorder (ADHD) in children, adolescents, and adults, and narcolepsy in adults and some children, depending on the specific product’s labeling.
Generic/Biosimilar name: Amphetamine.
Active ingredient: Amphetamine.
Administration route: Oral.
Typical oral amphetamine dosing for ADHD starts low (e.g., 2.5–5 mg once or twice daily in children, 5–10 mg in adults) and is slowly increased based on response and tolerability up to a product-specific maximum daily dose.
How It Works
- Amphetamine increases the levels and activity of natural brain chemicals called dopamine and norepinephrine, especially in areas that control attention and impulse control.
- It does this mainly by helping release these chemicals from nerve endings and blocking their reuptake, so they stay longer in the spaces between nerve cells.
- The result is improved focus, alertness, and ability to control impulses in many people with ADHD or narcolepsy.
Treatment and Efficacy
Approved indications: Oral amphetamine products are approved primarily for the treatment of attention-deficit/hyperactivity disorder (ADHD) and for narcolepsy (depending on the specific formulation and age group).
Off-label uses: Clinicians may sometimes prescribe amphetamine off-label for conditions such as treatment-resistant depression, certain forms of severe fatigue, or obesity, but these uses are less common and supported by more limited or mixed evidence compared with its use in ADHD and narcolepsy.
Efficacy expectations: For ADHD, many patients notice improved attention, reduced hyperactivity, and better impulse control within hours of the first dose, with full benefit typically assessed over several days to weeks of dose adjustment; for narcolepsy, daytime wakefulness can improve on the first day, though dosing may need titration for best effect.
Comparison to similar drugs: Amphetamine is generally comparable in effectiveness to other stimulant medications (such as methylphenidate) for ADHD, with some individuals responding better to one class than the other; nonstimulant options often have a slower onset of action and, on average, slightly lower effect sizes, but may be preferred in people who cannot tolerate stimulants.
Dosage and Administration
Typical dosing: For ADHD, treatment usually starts with a low oral dose once or twice daily (for example, a small dose of an immediate-release or extended-release product in the morning) and is increased gradually based on benefit and side effects up to the maximum daily dose specified for the particular product and age group; for narcolepsy, total daily doses are often similar or somewhat higher, divided one to several times per day.
How to take: Take amphetamine exactly as prescribed at the same time each day; many formulations are taken in the morning, with or without food, to reduce insomnia, and late-day doses are usually avoided; extended-release capsules should generally be swallowed whole, although some allow the contents to be sprinkled on soft food according to product instructions.
Special instructions: Do not crush or chew extended-release forms unless the labeling specifically allows sprinkling; avoid taking more than prescribed or using the medication to stay awake for nonmedical reasons; periodic breaks or reevaluation may be recommended by the clinician to reassess the ongoing need for treatment.
Missed dose: If a dose is missed, take it when remembered unless it is late in the day and likely to interfere with sleep, in which case skip it and take the next dose at the regular time; do not double doses to make up for a missed one.
Overdose: Overdose can cause severe agitation, confusion, hallucinations, very fast heart rate, dangerously high blood pressure, chest pain, seizures, or loss of consciousness; in suspected overdose, seek emergency medical care or contact emergency services or a poison control center immediately.
Safety and Side Effects
Common side effects: Frequently reported effects include decreased appetite, weight loss, trouble sleeping, dry mouth, increased heart rate, mild rise in blood pressure, nervousness, and stomach upset; these often appear soon after starting or increasing the dose and may lessen over time or with dose adjustment.
Serious or rare adverse effects: Seek immediate medical attention for chest pain, fainting, shortness of breath, signs of stroke, sudden severe headache, hallucinations, extreme agitation, unexplained wounds on fingers or toes (possible circulation problems), or signs of allergic reaction such as swelling of the face, lips, or throat.
Warnings and precautions: Amphetamine can worsen existing heart disease or serious heart rhythm problems and is generally avoided in people with known structural heart abnormalities, uncontrolled hypertension, or serious arrhythmias; caution is required in people with a history of substance use disorder, bipolar disorder, psychosis, or severe anxiety.
Pregnancy and breastfeeding: Use during pregnancy or while breastfeeding is only considered when potential benefits clearly outweigh risks, and decisions are individualized; discuss family planning, pregnancy, and lactation with a clinician before starting or continuing therapy.
Age limits and organ disease: Certain formulations are approved down to early childhood, while others are for older children, adolescents, or adults only; dose adjustments or closer monitoring may be needed in significant kidney impairment, and use is typically cautious in severe liver disease.
Safety compared with other drugs: Like other stimulants, amphetamine carries risks of increased blood pressure and heart rate, reduced appetite and growth concerns in children, and potential for misuse or dependence; when appropriately prescribed and monitored, it is generally well tolerated and considered safe for long-term use in many patients.
Side effect reporting and safety updates: Patients and caregivers can report suspected side effects to their prescriber and to national medicine-safety programs (such as the FDA’s MedWatch program in the United States) and can check official regulatory agency websites for updated safety communications and labeling changes.
Interactions and Precautions
Drug and OTC interactions: Amphetamine must not be taken with monoamine oxidase inhibitors (MAOIs) or within a recommended washout period due to risk of dangerously high blood pressure and other reactions; other medications that raise blood pressure or heart rate, certain antidepressants, antipsychotics, and some acid-reducing drugs can interact and may require dose adjustments or careful monitoring.
Supplements, foods, and alcohol: Large amounts of vitamin C or acidic foods and juices may reduce amphetamine absorption, while alkalinizing agents (such as some antacids) can increase blood levels; alcohol can increase side effects like dizziness or heart rate changes and is generally best limited or avoided while on this medicine.
Diagnostic or imaging procedures: Amphetamine can affect heart rate and blood pressure readings and may influence certain lab tests, so patients should tell healthcare professionals, including dentists and imaging staff, that they are taking a stimulant.
Conditions requiring precautions: Use requires special caution or may be avoided in people with significant cardiovascular disease, moderate to severe hypertension, hyperthyroidism, glaucoma, history of drug misuse, severe anxiety or agitation, psychosis, or certain types of bipolar disorder.
Monitoring needs: Blood pressure, heart rate, weight, and height (in children) are typically checked regularly; some patients with cardiovascular risk factors may need an ECG or other heart evaluation before or during treatment, as advised by their clinician.
Common Questions and Answers
Q: How long does amphetamine take to start working for ADHD?
A: Immediate-release forms usually start working within 30–60 minutes and last several hours, while extended-release forms begin working the same day and can last most of the school or work day.
Q: Will amphetamine change my personality?
A: When properly dosed, amphetamine is intended to improve focus and self-control rather than change who you are, though some people may feel more quiet or less talkative and doses may need adjustment if they feel "flat" or unlike themselves.
Q: Is amphetamine addictive?
A: Amphetamine has a potential for abuse and dependence, which is why it is a controlled substance, but in people with ADHD who take it as prescribed and are monitored, the risk of developing addiction is much lower than with nonmedical or recreational use.
Q: Can children take amphetamine safely?
A: Many children safely use amphetamine for ADHD under medical supervision, with regular checks of growth, appetite, heart rate, and blood pressure, and dose adjustments to balance benefits and side effects.
Q: Do I need to avoid caffeine while taking amphetamine?
A: Moderate caffeine intake is often acceptable, but because both caffeine and amphetamine are stimulants, too much caffeine can increase jitteriness, insomnia, or heart rate, so it is wise to limit caffeine and discuss your typical intake with your clinician.
Better Treatment, Lower Cost – No Catch.
Find safer, more effective medications with fewer side effects – often for less money. It’s fast, free, and personalized. Learn More →
Disposal Guidance
Storage: Keep amphetamine in its original, tightly closed container at room temperature, away from moisture, heat, and direct light; do not store in the bathroom, and keep out of reach of children, teens, and pets because it is a controlled substance with abuse potential.
Security: Store in a locked cabinet or other secure place and do not share the medication with anyone.
Disposal: Use a pharmacy or community drug take-back program when possible; if none is available, follow local guidance, which may include mixing tablets or capsules (not extended-release beads) with undesirable material (like used coffee grounds) in a sealed container before placing in household trash, unless the product label or local regulations direct otherwise.