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Medical Disclaimer: This tool provides estimates based on FDA-approved labeling and clinical guidelines. It does not replace professional medical advice. Always consult a prescribing physician before starting or adjusting medication.

Condition FDA-indicated condition

Age Group Patient age bracket

Body Weight

Used for weight-based dose estimation

Formulation IR = 4–6 hr duration; XR = 10–12 hr duration

Current Dose (optional)

mg/day

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Dosing Intensity Clinical starting point aggressiveness

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About

Amphetamine mixed salts (Adderall) dosing errors carry risk of cardiovascular adverse events, growth suppression in pediatric patients, and subtherapeutic response. FDA-approved starting doses differ by age bracket and formulation. Pediatric patients aged 6 - 12 typically initiate at 5 mg IR once daily, while adults may start at 5 - 20 mg/day. Weight-based guidance suggests 0.1 - 0.5 mg/kg/day for initial dosing, not exceeding the FDA ceiling of 40 mg/day for pediatric patients or 60 mg/day for adults. This calculator generates a starting dose estimate, titration schedule, and IR-to-XR equivalence based on published pharmacokinetic parameters and AAP clinical practice guidelines.

This tool approximates dosing under standard conditions. It does not replace clinical judgment. Comorbidities (hepatic impairment, cardiac history, concurrent CYP2D6 inhibitors) alter metabolism and require physician adjustment. Narcolepsy dosing follows a separate protocol with higher ceilings for adults. All outputs assume normal renal and hepatic function.

Formulas

The weight-based initial dose estimate uses body mass scaled by a conservative coefficient within the FDA-approved range:

D_start = W × k

where D_start = initial daily dose in mg/day, W = patient body weight in kg, and k = weight-based coefficient, typically 0.1 - 0.5 mg/kg/day (conservative start uses 0.15). The result is clamped to the nearest available tablet strength and never exceeds the FDA ceiling D_max:

D_final = min(round_tablet(D_start), D_max)

Available IR tablet strengths: 5, 7.5, 10, 12.5, 15, 20, 30 mg. Available XR capsule strengths: 5, 10, 15, 20, 25, 30 mg.

IR-to-XR equivalence follows a 1:1 total daily dose conversion. A patient on 10 mg IR BID (20 mg/day total) converts to 20 mg XR QAM. The titration dose at week n:

D_n = min(D_start + n × ΔD, D_max)

where ΔD = titration increment per step (typically 5 mg IR or 10 mg XR), and n = week number (0, 1, 2, ...).

Reference Data

Population	Formulation	Starting Dose	Titration Step	Titration Interval	Typical Range	FDA Max
Children 3-5 y (ADHD)	IR	2.5 mg/day	2.5 mg/week	7 days	2.5 - 40 mg/day	40 mg/day
Children 6-12 y (ADHD)	IR	5 mg QD - BID	5 mg/week	7 days	5 - 30 mg/day	40 mg/day
Children 6-12 y (ADHD)	XR	5 - 10 mg QAM	5 - 10 mg/week	7 days	5 - 30 mg/day	30 mg/day
Adolescents 13-17 y (ADHD)	IR	5 mg QD - BID	5 mg/week	7 days	5 - 40 mg/day	40 mg/day
Adolescents 13-17 y (ADHD)	XR	10 mg QAM	10 mg/week	7 days	10 - 30 mg/day	30 mg/day
Adults (ADHD)	IR	5 mg BID	5 mg/week	7 days	5 - 40 mg/day	60 mg/day
Adults (ADHD)	XR	20 mg QAM	10 mg/week	7 days	10 - 60 mg/day	60 mg/day
Children 6-12 y (Narcolepsy)	IR	5 mg/day	5 mg/week	7 days	5 - 60 mg/day	60 mg/day
Adolescents 13+ y (Narcolepsy)	IR	10 mg/day	10 mg/week	7 days	5 - 60 mg/day	60 mg/day
Adults (Narcolepsy)	IR	10 mg/day	10 mg/week	7 days	5 - 60 mg/day	60 mg/day
IR = Immediate Release (duration ~4-6 h). XR = Extended Release (duration ~10-12 h). QD = once daily. BID = twice daily. QAM = every morning. Sources: FDA-approved labeling, AAP ADHD Guidelines 2019.

Frequently Asked Questions

Weight-based dosing uses a coefficient of 0.1 - 0.5 mg/kg/day. A 30 kg child at 0.15 mg/kg/day yields 4.5 mg/day, rounded to the nearest 5 mg tablet. Heavier patients may tolerate higher starting doses but must never exceed FDA maximums. Weight-based estimates serve as a clinical starting point; titration is always guided by symptom response and tolerability, not weight alone.

IR (Immediate Release) delivers the full dose rapidly, reaching peak plasma concentration (T_max) in approximately 3 hours with a duration of 4 - 6 hours. XR (Extended Release) uses a dual-bead mechanism: 50% releases immediately and 50% releases approximately 4 hours later, providing 10 - 12 hours of coverage. Total daily dose equivalence is 1:1. A patient taking 10 mg IR twice daily converts to 20 mg XR once daily.

Pediatric patients (age 6 - 17) have a lower FDA-approved ceiling of 30 - 40 mg/day (formulation-dependent) compared to the adult ceiling of 60 mg/day. This reflects differences in hepatic metabolism maturity, cardiovascular risk profile, and growth suppression concerns. Chronic amphetamine exposure in children requires periodic height and weight monitoring because stimulants can reduce growth velocity by 1 - 2 cm/year during the first 1 - 2 years of treatment.

Titration follows a weekly increment protocol. For IR formulations, increase by 5 mg/week. For XR, increase by 5 - 10 mg/week. Titration stops at the lowest effective dose that produces adequate symptom control with tolerable side effects, or upon reaching the FDA maximum. Common dose-limiting side effects include insomnia, appetite suppression, tachycardia (resting heart rate > 100 bpm), and blood pressure elevation (> 10 mmHg above baseline).

No. Adderall is metabolized via CYP2D6 and is pH-sensitive for urinary excretion. CYP2D6 inhibitors (fluoxetine, paroxetine, quinidine) increase amphetamine plasma levels and may require dose reduction. Urinary alkalinizers (sodium bicarbonate, acetazolamide) decrease renal clearance, effectively increasing drug exposure. Urinary acidifiers (ascorbic acid, ammonium chloride) accelerate excretion. Concurrent MAOIs are contraindicated. These pharmacokinetic interactions require physician-guided adjustment beyond the scope of weight-based estimation.

Yes. Narcolepsy typically requires higher doses. Adults with narcolepsy may start at 10 mg/day and titrate up to 60 mg/day in divided IR doses. Narcolepsy dosing is only FDA-approved for the IR formulation. XR is not FDA-indicated for narcolepsy. The first dose is given upon waking, with subsequent doses at 4 - 6 hour intervals. Narcolepsy patients aged 6 - 12 start at 5 mg/day with 5 mg weekly increments.