Section 16 · Monograph
Risdiplam
Reviewed Nov 2026FDA label
EvrysdiSMN2 splicing modifier
- Forms
- Powder for oral solution: 60mg (0.75mg/mL after constitution) | Tab: 5mg
- Dose
- Once daily: under 2 months 0.15mg/kg | 2 months to <2 years 0.2mg/kg | 2 years+ under 20kg 0.25mg/kg | 2 years+ 20kg or more 5mg
- MOA
- Small molecule that ↑functional SMN protein
Indications
- Treatment of spinal muscular atrophy (SMA) in pediatric and adult patientsFDA-labeled
Mechanism of Action
- Small-molecule SMN2 pre-mRNA splicing modifier that increases full-length SMN protein systemically (CNS and peripheral tissues)
Full Dosing
Adult / usual
- Once daily after a meal, by age and weight: under 2 months 0.15mg/kg; 2 months to under 2 years 0.2mg/kg; 2 years and older under 20kg 0.25mg/kg; 2 years and older 20kg or more 5mg
- Oral solution (60mg powder, 0.75mg/mL after constitution by a pharmacist) for all ages; 5mg tablet available for patients prescribed the 5mg dose
- Store oral solution refrigerated
Contraindications
- None listed in labeling
Drug Interactions
- MATE1/MATE2-K substrates (e.g., metformin): exposure may increase — monitor
- Weak CYP3A inhibition (e.g., midazolam exposure may rise modestly)
Adverse Effects
- Fever, diarrhea, rash
- Upper respiratory infection, vomiting
- Embryo-fetal toxicity and male fertility effects in animal studies
- Retinal toxicity seen in animals (not in humans to date)
Monitoring Parameters
- Motor function and milestones
- Pregnancy testing and contraception counseling before and during treatment
- Infection and skin/GI tolerability
Pregnancy & Lactation
- Embryo-fetal toxicity in animals; verify pregnancy status before starting and counsel on contraception per label
- Breastfeeding: weigh benefit and risk; consult current label