What are the recommended starting doses and titration schedules for immediate‑release Adderall (mixed amphetamine salts) and gabapentin in adults and children?

Starting Doses for Adderall IR and Gabapentin

Adderall IR (Mixed Amphetamine Salts Immediate-Release)

Start Adderall IR at 5 mg once or twice daily in adults, or 2.5 mg once or twice daily in children, with weekly dose increases of 5–10 mg until symptoms are controlled. 1

Adult Dosing Protocol

• Initial dose: 5 mg once daily in the early morning, or 5 mg twice daily (after breakfast and lunch) 1
• Titration schedule: Increase by 5–10 mg increments each week based on symptom response and tolerability 1
• Target dose range: Most adults respond to total daily doses of 20–60 mg divided into 2–3 doses 2, 3
• Maximum dose: Up to 60 mg/day in divided doses, though some patients may require up to 1.0 mg/kg/day (approximately 65 mg for a 65 kg adult) if lower doses fail to control symptoms 1
• Duration of effect: Each dose provides approximately 4–6 hours of symptom control, necessitating multiple daily doses 4

Pediatric Dosing Protocol (Children ≥6 years)

• Initial dose: 2.5 mg once or twice daily 1
• Titration schedule: Increase by 2.5–5 mg increments weekly based on parent and teacher rating scales 1
• Weight-based considerations: For children weighing <25 kg (55 lbs), maximum total daily dose during titration should not exceed 35 mg 1
• Dosing frequency: Typically administered after breakfast and lunch, with an optional third dose after school for homework and social activities 1

Forced Titration Alternative

• Week 1: 5 mg (adults) or 2.5 mg (children) 1
• Week 2: 10 mg (adults) or 5 mg (children) 1
• Week 3: 15 mg (adults) or 7.5 mg (children) 1
• Week 4: 20 mg (adults) or 10 mg (children) 1
• After completing all four dose levels (1 week each), select the dose that produced maximum benefit with minimal side effects 1

Expected Efficacy and Response

• Approximately 70% of patients respond to either dextroamphetamine or methylphenidate alone; nearly 90% respond if both stimulants are tried sequentially 1
• Symptom improvement typically occurs within the first week of treatment at an effective dose 3
• Mean effect size for mixed amphetamine salts is 0.8, indicating robust clinical benefit 3
• In controlled trials, 70% of adults achieved ≥30% reduction in ADHD Rating Scale scores versus 7% with placebo 5

Critical Monitoring Requirements

• Obtain ADHD rating scales from teachers and parents (children) or from patient and significant other (adults) before each dose increase 1
• Monitor blood pressure, pulse, height, and weight at baseline, during titration, and at follow-up visits 1
• Cardiovascular changes with mixed amphetamine salts are typically minimal and clinically insignificant at therapeutic doses 6

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Gabapentin

Start gabapentin at 100–300 mg at bedtime on day 1, increase to 300 mg three times daily by day 3, then titrate by 300 mg every 3–7 days to reach the minimum effective dose of 1800 mg/day (600 mg three times daily). 7, 8, 9

Standard Adult Titration Protocol

• Day 1: 100–300 mg at bedtime 7, 8
• Day 2: 100–300 mg twice daily 8
• Day 3: 300 mg three times daily (total 900 mg/day) 8, 9
• Week 2: Increase to 600 mg three times daily (total 1800 mg/day) 9
• Weeks 3–8: If pain control remains inadequate, continue increasing by 300 mg every 3–7 days up to maximum 3600 mg/day (1200 mg three times daily) 7, 9

Therapeutic Dose Range and Evidence

• Minimum effective dose: 1800 mg/day in three divided doses 7, 9
• Target therapeutic range: 1800–3600 mg/day in three divided doses 7, 8, 9
• Evidence quality: Moderate-quality evidence shows 32–38% of patients achieve ≥50% pain reduction at 1800–3600 mg/day versus 17–21% with placebo (Number Needed to Treat = 6–8) 7, 9

Mandatory Three-Times-Daily Dosing

• Gabapentin must be administered three times daily because of nonlinear, saturable absorption pharmacokinetics 7, 8, 9
• Doses should be spaced no more than 12 hours apart 7
• Once-daily or twice-daily dosing leads to sub-therapeutic plasma levels and treatment failure 9

Elderly Patient Modifications

• Initial dose: 100–200 mg once daily at bedtime 7, 8
• Titration: Increase by 100–200 mg every 3–7 days (or longer) to minimize adverse effects 7, 8
• Rationale: Elderly patients have higher rates of dizziness (19%), somnolence (14%), peripheral edema (7%), and gait disturbance (9%), which increase fall risk 7, 9
• The effective dose in older adults may be lower than standard adult ranges 8

Renal Impairment Dose Adjustments (Mandatory)

Creatinine Clearance	Total Daily Dose	Dosing Frequency
≥60 mL/min	900–3600 mg	Three times daily
30–59 mL/min	400–1400 mg	Twice daily
15–29 mL/min	200–700 mg	Once daily
<15 mL/min	100–300 mg	Once daily

• Calculate creatinine clearance using the Cockcroft-Gault equation before initiating therapy—this is non-negotiable, especially in elderly patients 7, 8
• Gabapentin is eliminated primarily by renal excretion; dose reduction is mandatory based on renal function 7, 8, 9

Duration of Adequate Trial

• Allow 3–8 weeks for titration plus an additional 2 weeks at maximum tolerated dose before declaring treatment failure 7, 8, 9
• An adequate therapeutic trial requires approximately 2 months because analgesic efficacy develops gradually over several weeks, not immediately 7, 9

Common Adverse Effects

• Dizziness (19%), somnolence (14%), peripheral edema (7%), and gait disturbance (9%) are the most common side effects 7, 9
• These effects are typically mild to moderate, dose-dependent, and often transient, usually subsiding within approximately 10 days 7
• Adverse-event withdrawals occur in 11% of patients versus 8.2% with placebo (Number Needed to Harm = 30) 7

Critical Pitfalls to Avoid

• Never start at high doses (such as 800 mg four times daily) without gradual titration—this dramatically increases the risk of intolerable adverse effects, particularly in elderly patients 7
• Do not fail to assess renal function before initiating therapy 7, 8
• Do not assume treatment failure without completing a full 2-month trial at therapeutic doses (1800–3600 mg/day) 7, 9
• Avoid abrupt discontinuation—taper gradually over at least 1 week if stopping therapy 8
• Do not use once-daily or twice-daily dosing for standard immediate-release gabapentin 8, 9