Pregnancy
Severe
Textbook
Embryofetal toxicity.
Source: G&G 14e · p1398
Drug reference
Idelalisib
Tyrosine Kinase Inhibitor · Antineoplastic
Tyrosine Kinase InhibitorAntineoplastic
CDSCO approvedSchedule H
EXCRETION
—
not curated
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
Manufacturer advises avoid unless potential
FDA category + note
Top interactionssee all 12 →
- PregnancySevereTextbookG&G 14e · p1398
- AbemaciclibSevereDatabaseDDInter
- AcalabrutinibSevereDatabaseDDInter
- AdalimumabSevereDatabaseDDInter
Mechanism
Idelalisib is a selective oral inhibitor of phosphoinositide 3-kinase delta (PI3Kδ), the predominant PI3K isoform in B lymphocytes. By blocking PI3Kδ, it disrupts B-cell receptor signaling, chemokine-mediated homing, and microenvironmental survival signals in malignant B cells, inducing apoptosis and reducing lymph node infiltration. This targeted mechanism provides efficacy in CLL and follicular lymphoma while sparing PI3Kα-dependent insulin signaling and PI3Kβ-dependent platelet function.
Indications
Untreated chronic lymphocytic leukaemia (in combination with rituximab in adults)Chronic lymphocytic leukaemia that has been treated but relapsed within 24 months (in combination with rituximab in adults)relapsed or refractory B-cell malignancies (received at least two prior systemic therapies)CLL (in combination with rituximab)follicular B-cell non-Hodgkin lymphoma (FL)SLL
Dosing
- Adult
- rituximab by intravenous infusion. Rituximab, in combination with fludarabine and cyclophosphamide, is recommended as an option for the first-line treatment of chronic lymphocytic leukaemia. www.nice.org.uk/guidance/ta174 ▶ Idelalisib for treating chronic lymphocytic leukaemia (October 2015) NICE TA359 Rituximab, in combination with idelalisib, is recommended as an option for treatment in adults: .…
Pharmacokinetics
Half-life
8.2 h (elimination)
Bioavailability
food does not affect absorption
Metabolism
CYP3A4 system
Side effects
Common
feverchillscoughpneumoniafatiguenausearashhyperglycemiaelevated levels of triglycerides and liver enzymes
Serious
- liver toxicity (16%-18%, sometimes fatal)
- diarrhea or colitis (14%-20%, sometimes fatal)
- pneumonitis (4%)
- serious infections (21%-48%)
Pregnancy & lactation
Pregnancy
Manufacturer advises avoid unless potential
Lactation
Breastfeeding during therapy is contraindicated because of the potential for adverse reactions in nursing infants.
Drug interactions
Abemaciclib
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Acalabrutinib
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Adalimumab
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Alfentanil
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Alfuzosin
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Apalutamide
Severe
Database
Drug interaction classified as: metabolism, excretion
Source: DDInter
Artemether
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Avanafil
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Avapritinib
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Axitinib
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Baricitinib
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Related guidelines
Other Tyrosine Kinase Inhibitor drugs
Ask House about Idelalisib
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: Goodman & Gilman 14e, BNF·Verified: 2026-05-13 · House clinical team