**REMS Drug**


Trade Name(s)

  • Zydelig

Ther. Class.

Pharm. Class.
kinase inhibitors


  • Treatment of relapsed chronic lymphocytic leukemia (CLL) (in combination with rituximab).
  • Treatment of relapsed follicular B-cell non-Hodgkin's lymphoma in patients who have failed ≥2 previous systemic therapies.
  • Treatment of relapsed small lymphocytic lymphoma (SLL) in patients who have failed ≥2 previous systemic therapies.


Acts as an inhibitor of phosphatidylinositol 3–kinase; induces apoptosis and inhibits cell proliferation in malignant B-cell and tumor cells, also inhibits come cell-signaling pathways, chemotaxis, adhesion and cell viability.

Therapeutic Effect(s):

Decreased progression of lymphoma.


Absorption: Well absorbed following oral administration.

Distribution: Unknown.

Metabolism and Excretion: Undergoes hepatic metabolism mostly by CYP3A and other systems. Metabolites are excreted in feces (78%) and urine (14%).

Half-life: 8.2 hr.

TIME/ACTION PROFILE (↑ in progression-free survival†)

PO2 mo6 mo10–12 mo
† Noted for CLL.


Contraindicated in:

  • History of serious allergic reactions including anaphylaxis or toxic epidermal necrolysis
  • Concurrent use of strong inducers or substrates of CYP3A;
  • Concurrent use of other hepatotoxic drugs
  • Concurrent use of drugs that cause diarrhea
  • OB:  May cause fetal harm
  • Lactation: Discontinue idelalisib or discontinue breastfeeding.

Use Cautiously in:

  • Renal impairment (CCr ≤15 mL/min)
  • Underlying hepatic impairment (monitor for toxicity; safety and effectiveness in patients with baseline ALT or AST values >2.5 x ULN or bilirubin >1.5 x ULN not established)
  • Strong inhibitors of CYP3A (monitor for idelalisib toxicity)
  • Geri:  May be more sensitive to drug effects;
  • Rep:  Women with childbearing potential;
  • Pedi:  Safety and effectiveness not established.

Adverse Reactions/Side Effects

CNS: fatigue, headache, insomnia, weakness

Resp: PNEUMONITIS, cough, dyspnea, nasal congestion

CV: peripheral edema

GI: COLITIS/DIARRHEA, HEPATOTOXICITY, INTESTINAL PERFORATION, abdominal pain, ↑ liver enzymes, nausea, vomiting, stomatitis


F and E: hyponatremia

Endo: hyperglycemia, hypoglycemia

Hemat: NEUTROPENIA, anemia, thrombocytopenia

Metabolic: hypertriglyceridemia

MS: arthralgia


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



  • Blood levels and effectiveness may be ↓ by concurrent  strong CYP3A inducers  including carbamazepine,,  phenytoin  or  rifampin  ; avoid concurrent use.
  • Concurrent use of  strong inhibitors of CPY3A  including  ketoconazole  may ↑ blood levels and risk of toxicity; careful monitoring recommended.
  • Blood levels of  substrates of CYP3A  including  midazolam may be ↑ by idelalisib; avoid concurrent use.


PO (Adults): 150 mg twice daily, continued until disease progresses or unavoidable toxicity occurs; dose modification/interruption required for neutropenia or thrombocytopenia.


Tablets: 100 mg, 150 mg


  • Monitor for diarrhea (stools increased by >6 more/day); may occur at any time. Responds poorly to antidiarrheal agents; may respond to corticosteroids.  If moderate diarrhea (increase of 4–6 stools/day over baseline) occurs,  maintain dose and monitor at least weekly until resolved.  If severe diarrhea (increase of ≥7 stools/day over baseline) or diarrhea requiring hospitalization occurs,  withhold dose and monitor at least weekly until resolved, then resume idelalisib at 100 mg twice daily.  If life-threatening diarrhea occurs,  discontinue idelalisib permanently.
  • Monitor for signs and symptoms of pneumonitis (cough, dyspnea, hypoxia, interstitial infiltrates, decline >5% in oxygen saturation). Discontinue therapy with any symptoms of pneumonitis and treat with corticosteroids.
  • Monitor for signs and symptoms of intestinal perforation (moderate to severe diarrhea, new or worsening abdominal pain, chills, fever, nausea, vomiting). Discontinue idelalisib permanently if intestinal perforation occurs.
  • Assess for signs and symptoms of infection (fever), including pneumonia, sepsis, febrile neutropenia. CMV or viremia,  Pneumocystis jiroveci (PJP) periodically during therapy. If symptoms of infection, CMV infection or viremia, or PJP occur, interrupt therapy until infection resolved. If therapy resumed, monitor for CMV reactivation (positive PCR or antigen test) at least monthly. If PJP infection confirmed, discontinue therapy permanently.
  • Assess for cutaneous reactions (exfoliative dermatitis, rash, erythema, macular or maculo-papular rash, pruritus). Discontinue idelalisib if skin reactions occur.
  • Monitor for signs and symptoms of anaphylaxis (dyspnea, wheezing, facial swelling). Discontinue idelalisib if symptoms occur.

Lab Test Considerations:

Monitor AST, ALT, and serum bilirubin every 2 wks for 3 mo, then every 4 wks for next 3 mo, then every 1–3 mo thereafter.  If AST/ALT >3–5 times upper limit of normal or bilirubin >1.5–3 times upper limit of normal,  maintain dose and monitor weekly until ≤ 1 times upper limit of normal.  If AST/ALT >5–20 times upper limit of normal or bilirubin >3–10 times upper limit of normal,  withhold dose. Monitor at least weekly until AST/ALT and/or bilirubin <1 times upper limit of normal, then resume dose at 100 mg twice daily.  If AST/ALT >20 times upper limit of normal and/or if bilirubin >10 times upper limit of normal,  discontinue idelalisib permanently. Usually occurs within first 12 wks of therapy and reversible with dose interruption.

  • Monitor CBC and platelet counts at least every 2 wks for first 3 mo.  If neutropenia occurs and ANC is 1.0–<1.5 Gi/L,  maintain idelalisib dose.  If ANC 0.5–1.0 Gi/L,  maintain dose and monitor ANC at least weekly.  If ANC <0.5 Gi/L, interrupt idelalisib; monitor ANC at least weekly until ANC ≥0.5 Gi/L, then may resume idelalisib at 100 mg twice daily.
  • If thrombocytopenia occurs and platelets 50 to <75 Gi/L, maintain idelalisib dose. If platelets 25 to <50 Gi/L, maintain dose and monitor platelet count at least weekly. If platelets <25 Gi/L, interrupt idelalisib; monitor platelet counts at least weekly until platelet count ≥25 Gi/L, then may resume idelalisib at 100 mg twice daily.
  • May cause ↓ hemoglobin.

Potential Diagnoses


  • Avoid concurrent use of medications causing hepatotoxicity or diarrhea.
  • PO Administer twice daily without regard to food. Swallow tablets whole; do not crush, break, or chew.

Patient/Family Teaching

  • Instruct patient to take idelalisib as directed. If a dose is missed by less than 6 hrs take as soon as remembered; if missed by more than 6 hrs wait and take next scheduled dose at usual time. Advise patient to read  Medication Guide  before starting therapy and with each Rx refill in case of changes.
  • Advise patient to notify health care professional immediately if diarrhea (bowel movements increase by six or more/day), severe abdominal pain, severe skin reactions (painful sores or ulcers on skin, lips, or mouth; severe rash with blisters or peeling skin), signs and symptoms of anaphylaxis, fever or signs of infection occur, or if signs and symptoms of liver toxicity (yellowing of skin or whites of eyes, dark or brown urine, bruising, abdominal pain in upper right side, bleeding), pneumonitis (cough, dyspnea), occur.
  • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications.
  • Rep:  Caution female patient of teratogenic effects of idelalisib. Advise patient to use effective contraception and avoid breastfeeding during and for at least 1 mo after last dose of idelalisib. Advise patient to notify health care professional promptly if pregnancy is suspected.

Evaluation/Desired Outcomes

Decreased progression of lymphoma.

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