- PO (Adults and Children ≥6 yr and >70 kg): 40 mg/day initially; may ↑ every 3 days to a daily target dose of 80 mg/day given as a single dose in the morning or evenly divided doses in the morning and late afternoon/early evening; may further ↑ after 2–4 wk up to 100 mg/day. Concurrent use of CYP2D6 inhibitor (quinidine, fluoxetine, paroxetine): 40 mg/day initially; may ↑ if needed to 80 mg/day after 4 wk.
- PO (Children ≥6 yr and ≤70 kg): 0.5 mg/kg/day initially; may ↑ every 3 days to a daily target dose of 1.2 mg/kg, given as a single dose in the morning or evenly divided doses in the morning and late afternoon/early evening (not to exceed 1.4 mg/kg/day or 100 mg/day, whichever is less). Concurrent use of CYP2D6 inhibitor (quinidine, fluoxetine, paroxetine) or CYP2D6 poor metabolizer: 0.5 mg/kg/day initially; may ↑ if needed to 1.2 mg/kg/day after 4 wk.
Hepatic Impairment
- PO (Adults and Children ): Moderate hepatic impairment:↓ initial and target dose by 50%; Severe hepatic impairment:↓ initial and target dose to 25% of normal.
