Long-term safety and effectiveness of pramipexole in tetrahydrobiopterin deficiency

High-dose pramipexole therapy in BH4 deficiency can be complicated, like in Parkinson disease, by psychiatric adverse effects. Low-dose pramipexole therapy (∼0.010 mg/kg/day) has been safe and clinically effective on long-term follow-up, representing a helpful therapeutic option in patients with BH4 deficiency.