Paclitaxel !

A taxane that freezes microtubules so cells cannot divide. Used in ovarian, breast and lung cancer; premedication is needed to prevent allergic reactions.

Updated 2026-11-01

Class: Microtubule inhibitors
Target: β-tubulin (taxane site, inside the microtubule)
ATC code: L01CD01
WHO Model List of Essential Medicines

β-tubulin (taxane site, inside the microtubule)Paclitaxel

The structure shows paclitaxel bound to bovine α/β-tubulin; the taxane pocket is on β-tubulin, facing the inside of the microtubule.

Target in 3D: β-tubulin (taxane site, inside the microtubule). PDB structure 1JFF (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

Paclitaxel binds β-tubulin inside assembled microtubules, promotes their assembly and prevents them from breaking down. The rigid, abnormal bundles cannot reorganise into a working spindle, so cells arrest in mitosis and die. The same loss of microtubule dynamics in long nerve axons produces sensory neuropathy.

Paclitaxel binds β-tubulin inside the microtubule
Microtubules are stabilised and cannot disassemble
No dynamic spindle: mitotic arrest and cell death

Pharmacokinetics

Absorption: Intravenous infusion only.
Distribution: Wide, with slow release back from tissues.
Metabolism: Liver, by CYP2C8 and CYP3A4.

Indications

Ovarian carcinoma: first line with cisplatin, and later lines. Ovarian cancer →
Breast cancer: adjuvant after doxorubicin-containing chemotherapy in node-positive disease, and metastatic disease. Breast cancer →
Non-small cell lung cancer, first line with cisplatin. Lung cancer →
AIDS-related Kaposi sarcoma, second line.

Adverse effects

Common

Hair loss in almost all patients
Neutropenia
Peripheral sensory neuropathy
Joint and muscle pain
Low heart rate or blood pressure during the infusion; injection-site reactions

Contraindications

Hypersensitivity to paclitaxel or to other drugs formulated in polyoxyl 35 castor oil
Low baseline neutrophil count

Key interactions

Cisplatin: Paclitaxel given after cisplatin is cleared more slowly and causes more myelosuppression; paclitaxel goes first.
Doxorubicin: Paclitaxel given first raises doxorubicin levels; doxorubicin goes first.
CYP2C8 or CYP3A4 inhibitors (e.g. gemfibrozil) and inducers (e.g. rifampicin): Can raise or lower paclitaxel exposure.

What is monitored

Neutrophil count before each cycle
Vital signs during the infusion, especially the first hour
Symptoms of neuropathy
ECG monitoring if conduction problems appear

Administration and safety

Premedication with a corticosteroid, an antihistamine (H1) and an H2 blocker before every dose.
Prepared in glass, polypropylene or polyolefin containers and given through non-PVC (polyethylene-lined) tubing, to avoid leaching of the plasticiser DEHP.
Given through an in-line microporous filter.
Hazardous drug: prepared and given following hazardous-drug handling procedures (impervious gloves, no skin contact) and disposed of as cytotoxic waste.

Nursing care

Independent double check of drug, patient, route and cycle before giving it (high-alert medicine).
Confirm the premedication was given; stay with the patient at the start of the infusion with emergency drugs ready.
Watch for flushing, breathlessness, chest tightness, rash or low blood pressure; stop the infusion if they appear.
Blood count before each cycle; fever with neutropenia is treated as an emergency.
Teaching: hair loss is expected; report numbness, tingling or burning in hands and feet.

Pregnancy and breastfeeding

Can cause fetal harm; pregnancy is avoided during treatment.

Test yourself

Think of the answer, then tap the question to see it.

How does paclitaxel's action on microtubules differ from that of vincristine?

Paclitaxel stabilises microtubules and stops their disassembly; vincristine prevents them from assembling.

Which three drug groups are given as premedication before paclitaxel?

A corticosteroid (e.g. dexamethasone), an H1 antihistamine (e.g. diphenhydramine) and an H2 blocker.

Why is paclitaxel given through non-PVC tubing?

Its solvent can leach the plasticiser DEHP from PVC bags and sets.

When paclitaxel and cisplatin are combined, which is given first, and why?

Paclitaxel first: given after cisplatin it is cleared more slowly and causes more myelosuppression.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: DailyMed - PACLITAXEL injection, solution (DailyMed (U.S. National Library of Medicine), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 70 (McGraw Hill, 2023); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025).

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Representative model, for educational purposes only.