What is the maximum dose of orally disintegrating tablet (ODT) olanzapine for a 9‑year‑old child?

Maximum Olanzapine ODT Dose for a 9-Year-Old

For a 9-year-old child requiring acute behavioral management, olanzapine ODT can be dosed at 2.5 mg orally, with the option to repeat every 30–45 minutes up to a maximum of 30 mg daily, though pediatric experience is extremely limited and adverse effects are common at these doses. 1

Acute Agitation Dosing (Emergency/Inpatient Setting)

The American Academy of Pediatrics guideline for acute mental health emergencies in children provides the following framework for olanzapine use: 1

• Initial dose: 2.5 mg PO/ODT for prepubertal children (ages 6–12 years) 1
• Repeat dosing: May repeat every 30–45 minutes as needed 1
• Maximum daily dose: 30 mg per day 1
• Onset: 20–30 minutes for oral formulations 1
• Peak effect: 45–60 minutes 1
• Duration: 6–8 hours 1

The ODT formulation disintegrates rapidly (mean 15.78 seconds to initial disintegration, 0.97 minutes to complete disintegration) and is well-tolerated in terms of acceptability. 2

Chronic/Maintenance Dosing (Outpatient Setting)

For ongoing treatment beyond acute management, limited pediatric data exists:

• Weight-based dosing: 0.12–0.29 mg/kg/day has been studied in children ages 6–11 years 3
• Absolute dose range: 2.5–10 mg/day in preadolescent children 3
• Mean dose studied: 7.5 mg/day (range 2.5–10 mg/day) 3

For a typical 9-year-old weighing approximately 30 kg, this translates to roughly 3.6–8.7 mg/day based on weight, though the absolute maximum studied was 10 mg/day in this age group. 3

Critical Safety Considerations

All five preadolescent children (ages 6–11) in one open-label trial discontinued olanzapine within 6 weeks due to adverse effects or lack of efficacy, highlighting significant tolerability concerns in this age group: 3

• Sedation occurred in 60% of children 3
• Weight gain up to 16 pounds occurred in 60% 3
• Akathisia occurred in 40% 3
• Psychotic symptoms did not respond in children with overt hallucinations 3

An 18-month-old who ingested 30–40 mg experienced significant respiratory distress and mental status changes, requiring close monitoring. 4 This underscores the need for careful dose titration and monitoring in younger patients.

Practical Dosing Algorithm

For a 9-year-old requiring olanzapine:

1. Start low: Begin with 2.5 mg ODT 1, 3
2. Titrate slowly: In acute settings, may repeat every 30–45 minutes up to 30 mg/day maximum 1
3. Monitor closely: Watch for sedation, weight gain, and extrapyramidal symptoms after each dose 3
4. Reassess frequently: If no improvement after appropriate dosing over one month in chronic use, discontinue 5 (extrapolated from methylphenidate monitoring principles)
5. Consider alternatives: Given poor tolerability in preadolescents, other agents (risperidone, haloperidol with diphenhydramine) may be preferable 1

Comparison to Adolescent Dosing

Pharmacokinetic data in adolescents (ages 10–18) suggests that 5–10 mg once daily with a target of 10 mg/day is appropriate for most adolescent patients, with clearance and half-life similar to nonsmoking adults. 6 However, a 9-year-old prepubertal child should be dosed at the lower end of the pediatric range (2.5–5 mg) rather than using adolescent dosing. 1, 3

The maximum safe dose for a 9-year-old in acute settings is 30 mg/day per American Academy of Pediatrics guidelines, but expect significant adverse effects and consider this an absolute ceiling rather than a target. 1