Version July 2025
Spinal muscular atrophy (SMA):
Neonates: Oral: 0.15 mg/kg/dose once daily.
Spinal muscular atrophy (SMA):
Infants <2 months: Oral: 0.15 mg/kg/dose once daily.
Infants ≥2 months and Children <2 years: Oral: 0.2 mg/kg/dose once daily.
Children ≥2 years and Adolescents:
<20 kg: Oral: 0.25 mg/kg/dose once daily.
≥20 kg: Oral: 5 mg once daily.
There are no dosage adjustments provided in the manufacturer's labeling; however, renal impairment is not expected to alter exposure to risdiplam.
Mild to moderate impairment: No dosage adjustment needed based on data in patients ≥20 kg.
Severe impairment: There are no dosage adjustments provided in the manufacturer's labeling (has not been studied).
(For additional information see "Risdiplam: Drug information")
Spinal muscular atrophy : Oral: 5 mg once daily.
Missed dose:
≤6 hours since usual administration: Administer as soon as possible and resume usual dosing schedule the next day.
>6 hours since usual administration: Skip missed dose and administer next dose at usual administration time the next day.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling; however, renal impairment is not expected to alter exposure to risdiplam.
Mild to moderate impairment (Child-Pugh class A or B): No dosage adjustment needed.
Severe impairment (Child-Pugh class C): There are no dosage adjustments provided in the manufacturer's labeling (has not been studied).
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
>10%:
Dermatologic: Skin rash (17%; including allergic dermatitis, erythema of skin, erythematous rash, folliculitis, maculopapular rash, papular rash)
Gastrointestinal: Constipation (infants: ≥10%), diarrhea (17%), vomiting (infants: ≥10%)
Respiratory: Pneumonia (infants: ≥10%), upper respiratory tract infection (infants: ≥10%; including nasopharyngitis, rhinitis)
Miscellaneous: Fever (22%; including hyperpyrexia)
1% to 10%:
Gastrointestinal: Aphthous stomatitis (≤7%), oral mucosa ulcer (≤7%)
Genitourinary: Urinary tract infection (5%)
Neuromuscular & skeletal: Arthralgia (5%)
There are no contraindications listed in the US manufacturer's labeling.
Canadian labeling: Hypersensitivity to risdiplam or any component of the formulation.
Dosage form specific issues:
• Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP 1997; CDC 1982); some data suggest that benzoate displaces bilirubin from protein binding sites (Ahlfors 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. See manufacturer's labeling.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Oral:
Evrysdi: 0.75 mg/mL (80 mL) [contains edetate (edta) disodium dihydrate, polyethylene glycol (macrogol), sodium benzoate; strawberry flavor]
Tablet, Oral:
Evrysdi: 5 mg
No
Solution (reconstituted) (Evrysdi Oral)
0.75 mg/mL (per mL): $201.92
Tablets (Evrysdi Oral)
5 mg (per each): $1,346.12
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Oral:
Evrysdi: 0.75 mg/mL (80 mL) [contains edetate (edta) disodium dihydrate, polyethylene glycol (macrogol), sodium benzoate]
Oral: Administer with or without food at approximately the same time each day. For infants, may administer before or after breastfeeding. If dose is not fully swallowed or vomiting occurs after administration, do not administer another dose; resume regular schedule the following day.
Oral solution: Prepare dose only using the provided reusable oral syringe; do not use household tablespoon or other measuring device. Do not mix with milk, formula, or food. Administer immediately after drawing up into oral syringe. Administer 15 mL of water after administration to ensure dose is completely swallowed. Discard dose if not administered within 5 minutes of preparation. Wash syringe after each use.
Administration via feeding tube:
Gastric (eg, NG, G-tube) tubes: Draw up dose using provided enteral dosing syringe and administer via feeding tube. Following administration, flush feeding tube with 10 to 20 mL purified water to ensure entire dose is delivered.
Tablet: Swallow whole; do not chew, cut, or crush tablets; take with water. Tablets may also be placed in a cup and dispersed in 5 mL room temperature non-chlorinated water (eg, filtered water); do not use any other liquid for dispersion. Swirl cup gently for up to 3 minutes until fully mixed; some particles will remain. Administer immediately. To ensure no particles are left and entire dose is administered, refill cup with ≥15 mL of room temperature non-chlorinated water (eg, filtered water), swirl and administer immediately. Protect prepared dispersion from sunlight. Discard if not administered within 10 minutes of preparation.
Administration via feeding tube: NOT Recommended: Enteral feeding tube administration utilizing risdiplam tablets is not recommended. Use risdiplam oral solution for feeding tube administration.
Missed dose:
If a dose is missed ≤6 hours from the usual time it is taken, take the dose as soon as possible.
If >6 hours have passed since the missed dose, do NOT take the missed dose; resume regular schedule the following day.
Oral: Administer with or without food at approximately the same time each day.
Solution: Do not mix with milk. Instruct patients to drink water after taking dose to ensure it has been completely swallowed. If patient is unable to swallow, dose may be administered through a nasogastric or gastrostomy tube. Flush tube with water following administration. Prepare dose using the reusable oral syringe provided. Administer immediately after drawing up into oral syringe. If dose is not administered within 5 minutes, discard from the oral syringe and prepare a new dose. If vomiting occurs following dose or dose is not fully swallowed, another dose should not be administered; next dose should be administered at next regularly scheduled time.
Tablet: Swallow whole; do not chew, cut, or crush. Tablet may be placed in a small cup and dispersed in 5 mL of room temperature nonchlorinated drinking water (eg, filtered water); do not use any other liquids. Swirl gently for up to 3 minutes until fully mixed; some particles may remain. Avoid exposing prepared dispersion to sunlight. Administer immediately; discard if not used within 10 minutes of preparation. Refill cup with at least 15 mL of nonchlorinated drinking water, swirl, and administer immediately to ensure all particles are administered. Do not administer dispersed tablet via nasogastric or gastrostomy tube. If vomiting occurs following dose or dose is not fully swallowed, another dose should not be administered; next dose should be administered at next regularly scheduled time.
Oral solution: Prior to reconstitution, store the dry powder at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C to 30°C (59°F to 86°F). Keep in the original carton. Store reconstituted solution refrigerated at 2°C to 8°C (36°F to 46°F) and use within 64 days. Reconstituted solution may be removed and placed back in the refrigerator if needed; do not exceed 40°C (104°F) or a combined total of 5 days out of the refrigerator. Keep the reconstituted oral solution in the original amber bottle to protect from light.
Tablet: Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C to 30°C (59°F to 86°F). Protect from moisture.
Treatment of spinal muscular atrophy (SMA) (FDA approved in all ages).
Substrate of BCRP;
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program
MATE1/2-K Substrates (Clinically Relevant with Inhibitors): Risdiplam may increase serum concentration of MATE1/2-K Substrates (Clinically Relevant with Inhibitors). Management: Avoid use of risdiplam with MATE substrates if possible. If the combination cannot be avoided, monitor closely for adverse effects. Consider a reduced dose of the MATE substrate according to that substrate's labeling if appropriate. Risk D: Consider Therapy Modification
Evaluate pregnancy status prior to use in patients who could become pregnant.
Patients who could become pregnant should use effective contraception during therapy and for at least 1 month after the last risdiplam dose.
Adverse effects to male reproductive function and fertility were observed in animal toxicology studies; males of reproductive potential may want to consider sperm preservation prior to risdiplam therapy.
Based on data from animal reproduction studies, in utero exposure to risdiplam may cause fetal harm.
Data collection to monitor pregnancy and infant outcomes following exposure to risdiplam is ongoing. Health care providers are encouraged to enroll patients exposed to risdiplam during pregnancy in the pregnancy registry (833-760-1098). Patients may also enroll themselves.
Pregnancy test (in patients who can become pregnant) prior to initiation.
Treats spinal muscular atrophy caused by mutations in chromosome 5q that lead to survival motor neuron (SMN) protein deficiency; exerts effect by increasing exon 7 inclusion in SMN2 messenger ribonucleic acid transcripts and production of full-length SMN protein.
Distribution: Vdss: 6.3 L/kg.
Protein binding: ~89%, primarily to albumin.
Metabolism: Primarily hepatic via flavin monooxygenase 1 and 3 (FMO1 and FMO3); also metabolized by CYP1A1, 2J2, 3A4, and 3A7; forms inactive metabolite M1.
Half-life elimination: ~50 hours.
Time to peak: 3 to 4 hours; delayed up to 1 hour in fed state compared to fasted state.
Excretion: Feces: ~53% (14% as unchanged drug); urine: 28% (8% as unchanged drug).
