• Long-term treatment of patients with Gaucher disease type 1 who have been tested to be extensive metabolizers (EMs), intermediate metabolizers (IMs), or poor metabolizers (PMs) of the CYP2D6 enzyme system.

Contraindicated in:

• CYP2D6 ultra-rapid metabolizers (may not achieve effective concentrations)
• Concurrent use of strong or moderate CYP2D6 inhibitors with a strong or moderate CYP3A inhibitor in patients who are CYP2D6 EMs or IMs (↑ risk of cardiac arrhythmias)
• History of cardiac disease, long QT syndrome, or concurrent use of Class Ia or Class III antiarrhythmics
• Concurrent ingestion of grapefruit/grapefruit juice
• Moderate or severe renal impairment
• Moderate or severe hepatic impairment in patients who are CYP2D6 EMs (↑ risk of cardiac arrhythmias)
• Mild hepatic impairment in patients who are CYP2D6 EMs and are taking a strong or moderate CYP2D6 inhibitor (↑ risk of cardiac arrhythmias)
• Hepatic impairment (any degree) in patients who are CYP2D6 IMs or PMs (↑ risk of cardiac arrhythmias)
• Use of strong CYP3A inhibitors in patients who are CYP2D6 IMs or PMs (↑ risk of cardiac arrhythmias)
• Lactation: Lactation.

Use Cautiously in:

• CYP2D6 indeterminate metabolizers (dose not known)
• OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk
• Pedi: Safety and effectiveness not established in children.

CV: ARRHYTHMIA, heart block, palpitations, QT interval prolongation.

Derm: rash.

EENT: oropharyngeal pain.

GI: diarrhea, flatulence, nausea, upper abdominal pain, constipation, gastroesophageal reflux.

MS: arthralgia, back pain, extremity pain.

Neuro: fatigue, headache, dizziness.

General

Drug-Drug:

• Class Ia antiarrhythmics (including procainamide and quinidine) or Class III antiarrhythmics (including amiodarone, dofetilide, dronedarone, and sotalol) ↑ risk of cardiac arrhythmias; concurrent use contraindicated.
• Strong CYP3A inducers, including carbamazepine, phenobarbital, phenytoin, and rifampin, may ↓ levels and effectiveness; concurrent use not recommended.
• May ↑ levels and risk of toxicity of P-glycoprotein substrates, including digoxin (↓ digoxin dose by 30% and monitor digoxin levels), colchicine, dabigatran, and phenytoin (monitor drug levels, consider dose ↓/titration).
• May ↑ levels and risk of toxicity of CYP2D6 substrates, including metoprolol, tricyclic antidepressants , and phenothiazines; monitor drug levels; consider dose ↓/titration.

Drug-Natural Products:

• St. John's wort may ↓ levels and effectiveness; concurrent use not recommended.

Drug-Food:

• Grapefruit/grapefruit juice↑ risk of cardiac arrhythmias; concurrent ingestion contraindicated.

For EMs

Drug-Drug:

• Concurrent use of strong or moderate CYP2D6 inhibitors and strong or moderate CYP3A inhibitors↑ risk of cardiac arrhythmias; concurrent use contraindicated.
• Concurrent use of strong CYP2D6 inhibitors, including paroxetine, ↑ risk of potentially serious cardiac events; once-daily dosing recommended.
• Concurrent use of moderate CYP2D6 inhibitors, including terbinafine, ↑ risk of potentially serious cardiac events; once-daily dose recommended.
• Concurrent use of strong CYP3A inhibitors, including ketoconazole, ↑ risk of potentially serious cardiac events; once-daily dose recommended.
• Concurrent use of moderate CYP3A inhibitors, including fluconazole, ↑ risk of potentially serious cardiac events; once-daily dose recommended.

For IMs

Drug-Drug:

• Concurrent use of strong or moderate CYP2D6 inhibitors and strong or moderate CYP3A inhibitors↑ risk of cardiac arrhythmias; concurrent use contraindicated.
• Concurrent use of strong CYP3A inhibitors, including ketoconazole, ↑ risk of cardiac arrhythmias; concurrent use contraindicated.
• Strong CYP2D6 inhibitors, including paroxetine, ↑ risk of potentially serious cardiac events; once-daily dose recommended.
• Moderate CYP2D6 inhibitors, including terbinafine, ↑ risk of potentially serious cardiac events; once-daily dose recommended.
• Moderate CYP3A inhibitors, including fluconazole, ↑ risk of potentially serious cardiac events; concurrent use not recommended.

For PMs

Drug-Drug:

• Strong CYP3A inhibitors, including ketoconazole, ↑ risk of cardiac arrhythmias; concurrent use contraindicated.
• Moderate CYP3A inhibitors, including fluconazole, ↑ risk of potentially serious cardiac events; concurrent use not recommended.
• Weak CYP3A inhibitors↑ risk of potentially serious cardiac events; concurrent use not recommended.

(Generic available)

• Capsules: 84 mg;

• PO (Adults): CYP2D6 EMs or IMs: 84 mg twice daily; CYP2D6 PMs: 84 mg once daily; CYP2D6 EMs or IMs taking strong or moderate CYP2D6 inhibitor or CYP2D6 EMs taking strong or moderate CYP3A inhibitor: 84 mg once daily.

Cerdelga

• Acts as a specific inhibitor of glucosylceramide synthase, thereby reducing the substrate that accumulates in Gaucher disease type 1.

• Improvement in symptoms of Gaucher disease (anemia, thrombocytopenia, bone disease, splenomegaly, and hepatomegaly).

Therapeutic Classification: n/a

Pharmacologic Classification: glucosylceramide synthase inhibitors

Absorption: EMs — 5% absorbed following oral administration (due to extensive first-pass metabolism).

Distribution: Distributes mainly into plasma.

Metabolism/Excretion: Extensively metabolized, primarily by the CYP2D6 isoenzyme, with some metabolism by the CYP3A4 isoenzyme; 41.8% excreted in urine and 51.4% in feces mostly as metabolites.

Half-life: EMs: 6.5 hr; PMs: 8.9 hr.

(plasma concentrations)

• Instruct patient to take eliglustat as directed. Omit missed doses and take next scheduled dose; do not double doses. Advise patient to read Medication Guide before starting therapy and with each Rx refill in case of changes.
• Advise patient to avoid grapefruit and grapefruit juice during therapy.
• Inform patient of the purpose of this medication and the importance of treatment at least every 4 wk. Eliglustat helps control the symptoms but does not cure Gaucher disease. Lifelong therapy may be required.
• Advise patient to notify health care professional if palpitations, fainting, or dizziness occur.
• Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications, especially St. John's wort.
• Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected and to avoid breastfeeding during therapy.
• Emphasize the importance of follow-up examinations and lab tests.

e-LIG-lu-stat