Risdiplam Tablets (Evrysdi) are an oral SMN2 splicing modifier indicated for the treatment of spinal muscular atrophy (SMA) in pediatric and adult patients. As a targeted therapeutic drug requiring long-term use, its clinical application must strictly comply with guidelines and be supported by systematic monitoring.
Precautions for Risdiplam Tablets (Evrysdi) Administration
1. Dosage and Administration
(1) Dosage Adjustment: Dosage is calculated precisely based on age and body weight:
< 2 months old: 0.15 mg/kg
2 months – 2 years old: 0.2 mg/kg
≥ 2 years old and body weight < 20 kg: 0.25 mg/kg
≥ 20 kg: Fixed dose of 5 mg per day
(2) Tablet Administration: Tablets must be swallowed whole or dispersed in 5 mL of non-chlorinated drinking water (e.g., filtered water). The dispersion must be consumed within 10 minutes. Administration via nasogastric tube or gastrostomy tube is prohibited.
(3) Missed Dose Handling: If a missed dose is noticed within 6 hours, take it immediately. If more than 6 hours have passed, skip the missed dose and take the next dose as scheduled the following day.
2. Medication for Special Populations
(1) Hepatic Impairment: No dosage adjustment is required for mild to moderate hepatic impairment; careful evaluation is necessary for patients with severe hepatic impairment.
(2) Pregnancy: Animal studies have demonstrated embryotoxicity. Women of reproductive age must use effective contraceptive measures during treatment and for 1 month after discontinuing the drug. Use during pregnancy is recommended to be avoided.
(3) Lactation: The drug may be excreted in breast milk. The necessity of treatment should be weighed to decide whether to suspend breastfeeding.
3. Drug Interactions
(1) MATE Transporter Substrates: Concomitant use with drugs excreted via MATE1/MATE2-K (e.g., metformin) should be avoided. If co-administration is necessary, monitor for toxicity and adjust dosages as needed.
(2) CYP3A Inhibitors/Inducers: Strong CYP3A modulators have minimal impact on the pharmacokinetics of risdiplam, but potential interference with other metabolic pathways should be cautiously monitored.
4. Common Adverse Reactions
(1) Infantile SMA: The most common adverse reactions are fever (22%), diarrhea (17%), and rash (17). Additionally, upper/lower respiratory tract infections, constipation, vomiting, and cough require attention.
(2) Late-Onset SMA: The incidence of fever, diarrhea, and rash is ≥ 10%. Oral ulcers, joint pain, and urinary tract infections should be vigilantly monitored.
Medication Monitoring for Risdiplam Tablets (Evrysdi)
1. Laboratory Monitoring
(1) Pre-Treatment Mandatory Tests: Complete blood count, coagulation function, baseline electrocardiogram (ECG), and thyroid function.
(2) Regular Follow-Up: Complete blood count once a month (continuing until 48 months after the last dose); annual skin examinations to screen for melanoma.
2. Key Patient Education Points
(1) Self-Monitoring: Recognize emergency symptoms such as persistent fever (> 48 hours), severe diarrhea, and progressive rash.
(2) Emergency Management: If the drug solution comes into contact with skin or eyes, rinse immediately with clean water. Do not take an additional dose after vomiting; take the regular dose as scheduled the next day.
(3) Storage Requirements: Once reconstituted, the oral solution should be refrigerated (2–8°C) and used within 64 days; tablets should be stored in a moisture-proof environment.
