risdiplam

General

Pronunciation:
ris-diplam


Trade Name(s)

  • Evrysdi

Ther. Class.

none assigned

Pharm. Class.

survival of motor neuron 2 splicing modifiers

Indications

Spinal muscular atrophy.

Action

Acts as a survival of motor neuron 2 (SMN2) splicing modifier, which facilitates production of full-length SMN in patients with spinal muscular atrophy caused by genetic mutations leading to SMN protein deficiency.

Therapeutic Effect(s):

  • Improvement in ability to sit without support and improvement in survival without requiring permanent ventilation in infantile-onset spinal muscular atrophy.
  • Improved motor function in later-onset spinal muscular atrophy.

Pharmacokinetics

Absorption: Well absorbed following oral administration.

Distribution: Extensively distributed to extravascular tissues.

Metabolism and Excretion: Primarily metabolized by flavin monooxygenase 1 and 3 as well as the CYP1A1, CYP2J2, CYP3A4, and CYP3A7 isoenzymes. Primarily excreted in feces (53%; 14% as unchanged drug), with 28% excreted in urine (8% as unchanged drug).

Half-life: 50 hr.

TIME/ACTION PROFILE (plasma concentrations)

ROUTEONSETPEAKDURATION
POunknown1–4 hrunknown

Contraindication/Precautions

Contraindicated in:

  • None.

Use Cautiously in:

  • Severe hepatic impairment;
  • Rep:   Women of reproductive potential;
  • OB:  Safety not established in pregnancy;
  • Lactation:  Safety not established in breastfeeding.

Adverse Reactions/Side Effects

Derm: rash

EENT: nasopharyngitis, rhinitis, upper respiratory tract infection

GI: constipation, diarrhea, vomiting, mouth ulcers

GU: ↓ fertility (males), urinary tract infection

MS: arthralgia

Resp: pneumonia

Misc: fever

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

May ↑ levels and risk of toxicity of  metformin ; avoid concurrent use.

Route/Dosage

PO (Adults and Children ≥2 yr and ≥20 kg): 5 mg once daily.

PO (Adults and Children ≥2 yr and <20 kg): 0.25 mg/kg once daily.

PO (Children 2 mo–<2 yr): 0.2 mg/kg once daily.

PO (Children <2 mo): 0.15 mg/kg once daily.

Availability

Powder for oral solution (strawberry flavor): 0.75 mg/mL

Assessment

  • Assess symptoms of spinal muscular dystrophy (muscle weakness and decreased muscle tone, limited mobility, breathing problems, problems eating and swallowing, delayed gross motor skills, spontaneous tongue movements) before and periodically during therapy.

Implementation

  • PO Administer once daily after a meal at the same time each day. Use reusable oral syringe provided to ensure accurate dose. Must be administered within 5 min of drawing into syringe or must be discarded and redrawn. Solution is greenish yellow to yellow. For breastfeeding infants, administer after breastfeeding; do not mix with formula or milk. Instruct patient to drink water after taking to ensure completely swallowed. May be administered via nasogastric or gastrostomy tube; flush with water after administration. Prepared solution should be stored in a refrigerator for to 64 days.

Patient/Family Teaching

  • Instruct patient parent or caregiver in correct administration technique using syringe provided. Use syringe provided to draw up medication and administer within 5 min of drawing up. Administer missed doses as soon as possible if within 6 hr of missed dose; then resume dosing schedule next day. Otherwise, omit missed dose and resume regular scheduled next day. If dose is not fully swallowed or vomiting occurs after taking a dose, omit dose; do not administer to make up for lost dose. Advise patient to read  Patient Information  before starting therapy and with each Rx refill in case of changes.
  • Inform patient that risdiplam should come from the pharmacy as a liquid that can be given by mouth or through a feeding tube. The liquid solution is prepared by pharmacist. If the medicine in the bottle is a powder, do not use it. Contact your pharmacist for a replacement.
  • • Caution patient to avoid getting risdiplam on skin or in eyes. If risdiplam gets on skin, wash the area with soap and water. If risdiplam gets in eyes, rinse eyes with water.
  • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking any Rx, OTC, or herbal products.
  • Rep:   May cause fetal harm. Advise females or reproductive potential to use effective contraception during and for 1 month after last dose. Advise patient to notify health care professional immediately if pregnancy is planned or suspected or if breastfeeding. May impair male fertility; may consider sperm preservation prior to treatment. Encourage pregnant patients to enroll in pregnancy exposure registry that monitors outcomes of women exposed to risdiplam during pregnancy by contacting 1-833-760-1098 or visit https://www.evrysdipregnancyregistry.com.

Evaluation/Desired Outcomes

  • Improvement in ability to sit without support and improvement in survival without requiring permanent ventilation in infantile-onset spinal muscular atrophy.
  • Improved motor function in later-onset spinal muscular atrophy.