My Healing CommunityIntegrative Oncology Field Guide

Oncology drugs where CYP3A4 and P‑gp are important pharmacokinetic (PK) considerations

Reference table for oncology drugs with clinically relevant CYP3A4 and P-glycoprotein pharmacokinetic considerations.

This sheet summarises oncology drugs where CYP3A4 and P‑gp are important pharmacokinetic considerations.

What's on the table:

Drug name
The generic name and, in brackets, a common brand name.

Class
The therapeutic class or mechanism category. Examples include CDK4/6 inhibitor, EGFR TKI, PARP inhibitor, VEGFR TKI, SERM, and aromatase inhibitor.

Key metabolic pathways
The main bio-transformation and clearance routes. These include dominant CYP isoenzymes, UGTs, non-CYP mechanisms, and renal or fecal elimination.
They highlight where CYP3A4/P-gp-active compounds may change exposure.

Tmax
Approximate time to maximum plasma concentration after an oral dose. For depot drugs, it is measured after injection. It indicates how quickly a drug peaks and when overlapping exposures may matter most.

Half-life
Approximate terminal elimination half-life. It indicates persistence and accumulation. Longer half-lives mean greater sensitivity to sustained CYP3A4 inhibition or induction.

Dose-limiting / key toxicity
The adverse effects that constrain dosing in practice. This is a clinical red-flag column.
PK-driven exposure changes can have tangible safety consequences.

How to use this sheet

Feel free to copy information above about your medicines into personal notes or a treatment journal.

If your drug is not listed, you might ask an AI assistant:

For [enter your drug name], can you tell me the:

  1. drug class;

  2. key metabolic pathways, especially CYP3A4 and transporters;

  3. typical Tmax; (initial supplement overlap period of concern)

  4. usual half-life; (broader preiod for supplement overlap concern)

  5. main dose-limiting or key toxicities?

Not every drug listed is a “pure” CYP3A4 substrate. Some have mixed or minimal CYP3A4 metabolism.

Evidence type for all drugs on this table is Clinical PK and drug label.

Drug name

Drug Class

Key metabolic pathways

Evidence type

Tmax

Half-life

Dose-limiting / key toxicity

Palbociclib (Ibrance)

CDK4/6 inhibitor

Mostly metabolized by CYP3A4, with additional metabolism via SULT2A1; minimal renal clearance.

Clinical PK and FDA label; in vitro metabolism characterization.

≈ 6 h (range ≈ 3–12 h; food-dependent)

≈ 29 h (mean ≈ 29 ± 5 h)

Neutropenia is the main dose-limiting toxicity; leukopenia, anemia, fatigue and GI effects also common.

Ribociclib (Kisqali)

CDK4/6 inhibitor

Hepatic metabolism predominantly via CYP3A4; limited renal clearance.

Clinical PK and label; in vitro CYP profiling.

≈ 1–5 h

≈ 32–36 h

Neutropenia and other hematologic toxicity; QTc prolongation and hepatotoxicity are major safety signals requiring ECG/LFT monitoring.

Abemaciclib (Verzenio)

CDK4/6 inhibitor

Metabolized via CYP3A4; more lipophilic with broader tissue distribution; minimal renal clearance.

Clinical PK and label; in vitro metabolism.

≈ 8 h

≈ 18–38 h (mean ≈ 18 h)

GI toxicity (diarrhea) and fatigue are dose-limiting; neutropenia occurs but is less frequent/severe than palbociclib/ribociclib.

Erlotinib (Tarceva)

EGFR TKI

Primarily metabolized by CYP3A4, with contributions from CYP1A2 and CYP2C8; biliary/fecal excretion.

Clinical PK and label; DDI/safety reviews.

≈ 4 h

> 36 h

Skin rash and diarrhea are characteristic and can be dose-limiting; hepatotoxicity relevant.

Gefitinib (Iressa)

EGFR TKI

Metabolized mainly by CYP3A4 and CYP2D6; fecal excretion.

Clinical PK and label.

≈ 3–7 h

≈ 41 h

Diarrhea and acneiform rash common; hepatotoxicity can be dose-limiting.

Osimertinib (Tagrisso)

EGFR TKI (3rd-gen)

Mostly metabolized by CYP3A4/5; active metabolites contribute; mainly fecal elimination.

Clinical PK and label; comparative EGFR-TKI analyses.

≈ 6 h

≈ 48–60 h

Diarrhea, rash, ILD/pneumonitis, QTc prolongation, cardiomyopathy.

Ibrutinib (Imbruvica)

BTK inhibitor (covalent)

Mostly metabolized by CYP3A4; metabolites excreted mainly in feces.

Clinical PK and label; BTK inhibitor reviews.

≈ 1–2 h

≈ 4–6 h

Bleeding, atrial fibrillation, hypertension, diarrhea.

Acalabrutinib (Calquence)

BTK inhibitor

Metabolized by CYP3A4; greater BTK selectivity.

Clinical PK and label; comparative BTK reviews.

≈ 0.5–2 h

≈ 1–2 h

Headache, diarrhea, infections, cytopenias; bleeding and CV AEs less frequent than with ibrutinib.

Zanubrutinib (Brukinsa)

BTK inhibitor

Metabolized by CYP3A4; optimized BTK selectivity.

Clinical PK and label.

≈ 2 h

≈ 2–4 h

Neutropenia, infections, hypertension; bleeding and cytopenias.

Imatinib (Gleevec)

BCR-ABL / KIT / PDGFR TKI

Metabolized mainly by CYP3A4; active metabolite contributes.

Clinical PK and label; targeted-therapy reviews.

≈ 2–4 h

≈ 18 h

Myelosuppression, edema, GI symptoms, hepatotoxicity.

Sunitinib (Sutent)

VEGFR/MET/PDGFR TKI

Metabolized primarily by CYP3A4 to active metabolite; fecal elimination.

Clinical PK and label; VEGF-pathway inhibitor reviews.

≈ 6–12 h

≈ 40–60 h

Hypertension, fatigue, hand-foot syndrome, hypothyroidism, hepatotoxicity, cardiac events.

Sorafenib (Nexavar)

RAF/VEGFR/PDGFR TKI

Metabolized mainly by CYP3A4 and UGT1A9; excreted in feces.

Clinical PK and label.

≈ 3 h

≈ 25–48 h

Hand-foot skin reaction, diarrhea, hypertension, fatigue, rash, hepatotoxicity, cardiac ischemia.

Dasatinib (Sprycel)

BCR-ABL / SRC TKI

Metabolized predominantly by CYP3A4.

Clinical PK and label.

≈ 0.5–3 h

≈ 3–5 h

Myelosuppression, pleural effusions, bleeding, QTc prolongation.

Tamoxifen (Nolvadex)

SERM

Metabolized by CYP3A4, CYP2D6 and others to active metabolites (endoxifen).

Clinical PK and label; in vitro CYP studies.

≈ 4–7 h

≈ 5–7 days (parent)

Endometrial cancer risk, venous thromboembolism, hot flushes.

Anastrozole (Arimidex)

Aromatase inhibitor

Metabolized via hepatic phase I/II pathways with minor CYP involvement.

Clinical PK and label.

≈ 2 h

≈ 40–50 h

Arthralgia, bone density loss/fracture risk, hot flushes.

Letrozole (Femara)

Aromatase inhibitor

Hepatic metabolism mainly via CYP3A4 and CYP2A6; excreted in urine and feces.

Clinical PK and label.

≈ 1–2 h

≈ 48 h

Arthralgia, bone loss, hypercholesterolemia, hot flushes.

Fulvestrant (Faslodex)

SERD (IM)

Extensive hepatic metabolism mainly via CYP3A4 to inactive metabolites.

Clinical PK and label.

Tmax ≈ 7 days (IM)

≈ 40–50 days

Injection-site reactions, hepatotoxicity, GI effects.

Exemestane (Aromasin)

Steroidal aromatase inhibitor

Metabolized by CYP3A4 and reduction; metabolites excreted via urine and feces.

Clinical PK and label.

≈ 1–2 h

≈ 24 h

Hot flushes, arthralgia, fatigue, bone loss.

Olaparib (Lynparza)

PARP inhibitor

Metabolized mostly via CYP3A4; eliminated via urine and feces.

Clinical PK and label; PARP-inhibitor reviews.

≈ 1.5–3 h

≈ 12–15 h

Anemia, neutropenia, thrombocytopenia, nausea, fatigue; rare MDS/AML.

Niraparib (Zejula)

PARP inhibitor

Metabolized via non-CYP pathways (e.g. carboxylesterases); minor CYP involvement; renal/fecal elimination.

Clinical PK and label; PARP-inhibitor reviews.

≈ 3–4 h

≈ 36–48 h

Thrombocytopenia, anemia, neutropenia, hypertension, fatigue.

Talazoparib (Talzenna)

PARP inhibitor

Limited metabolism; excreted primarily unchanged; minor CYP involvement.

Clinical PK and label; PARP-inhibitor reviews.

≈ 2 h

≈ 90 h

Anemia, other cytopenias, fatigue, nausea.

Rucaparib (Rubraca)

PARP inhibitor

Metabolized by CYP2D6 and CYP1A2 with contributions from CYP3A4; renal/fecal excretion.

Clinical PK and label; PARP-inhibitor reviews.

≈ 1.5–3 h

≈ 17–20 h

Nausea, fatigue, elevated liver enzymes, cytopenias.

Bevacizumab (Avastin)

Anti-VEGF mAb

Proteolytic catabolism; not CYP-metabolized; IV administration.

Clinical PK and label; VEGF-targeted therapy reviews.

Peak at end of infusion

≈ 20 days

Hypertension, proteinuria, bleeding, GI perforation, impaired wound healing, thromboembolism.

Axitinib (Inlyta)

VEGFR TKI

Metabolized primarily by CYP3A4/5, with contributions from CYP1A2, CYP2C19, UGT1A1.

Clinical PK and label; VEGF-inhibitor reviews.

≈ 2.5–4 h

≈ 2.5–6 h

Hypertension, diarrhea, fatigue, hand-foot syndrome; hypertensive crises/thromboembolism.

Pazopanib (Votrient)

VEGFR/PDGFR TKI

Metabolized mainly by CYP3A4 with minor CYP1A2/CYP2C8 involvement.

Clinical PK and label; VEGF-pathway reviews.

≈ 2–4 h

≈ 30 h

Hepatotoxicity, hypertension, diarrhea, hair color changes.

On this page