TAXOL

Clinical safety rating: caution

Comprehensive clinical and safety monograph for TAXOL (TAXOL).

How it works

Paclitaxel stabilizes microtubules by binding to the β-tubulin subunit, preventing depolymerization, thereby disrupting mitotic spindle formation, cell division, and intracellular transport.

What the body does with it

Metabolism	Primarily hepatic metabolism via CYP2C8 and CYP3A4; biliary and fecal excretion; less than 10% excreted renally as unchanged drug.
Excretion	Primarily hepatic metabolism via CYP2C8 and CYP3A4; biliary/fecal excretion accounts for ~70% of total clearance; renal excretion is minimal (<10% as unchanged drug).
Half-life	Terminal elimination half-life is approximately 5.3 to 16.3 hours (mean ~13 hours); exhibits triphasic elimination with a prolonged terminal phase due to extensive tissue binding.
Protein binding	89–98% bound to plasma proteins, primarily to albumin and alpha1-acid glycoprotein.
Volume of Distribution	Large volume of distribution, ranging from 227 to 688 L/m² (approx. 3–10 L/kg), indicating extensive tissue binding and distribution.
Bioavailability	Not available orally due to poor bioavailability (<5%); administered intravenously. Oral formulations under investigation show bioavailability <10%.
Onset of Action	For paclitaxel, onset of clinical effect (e.g., antimitotic activity) is within minutes to hours of intravenous administration; peak plasma concentrations achieved at end of infusion.
Duration of Action	Duration of action is prolonged, with myelosuppression (neutropenia) nadir at 7–14 days, recovery typically by 21 days; schedule-dependent effects require 3-week cycles.

Classification & Brands

Action Class	Antimicrotubule agents- Taxanes
Brand Substitutes	Oncotaxel 100mg Injection, Altaxel 100mg Injection, Cytax 100mg Injection, Mitotax 100mg Injection, Paclitec 100 Injection, Oncotaxel 30mg Injection, Paclistar 30mg Injection, Chemotax 30mg Injection, Paclicad 30mg Injection, Axitaxel 30 Injection

Dosing & administration

Intravenous infusion of 175 mg/m² over 3 hours every 3 weeks for ovarian carcinoma; 135 mg/m² over 24 hours every 3 weeks for breast carcinoma; 100 mg/m² over 3 hours every 2 weeks for NSCLC; 175 mg/m² over 3 hours every 2 weeks for AIDS-related Kaposi sarcoma.

Dosage form	INJECTABLE
Renal impairment	No dose adjustment required for mild to moderate renal impairment (CrCl >20 mL/min). For severe renal impairment (CrCl ≤20 mL/min), reduce dose by 25% and monitor closely.
Liver impairment	For Child-Pugh A (bilirubin ≤1.5× ULN and AST/ALT ≤10× ULN): no adjustment. For Child-Pugh B (bilirubin 1.5-3× ULN): reduce dose by 25-50%. For Child-Pugh C (bilirubin >3× ULN): avoid use or reduce dose by 75% with extreme caution.
Pediatric use	Not FDA-approved for pediatric use. In clinical studies, doses of 250-350 mg/m² as a 24-hour infusion every 3 weeks have been used, but safety and efficacy are not established.
Geriatric use	No specific dose adjustment based on age alone. Monitor for increased myelosuppression, neuropathy, and other toxicities. Elderly patients may require dose reduction based on tolerance.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for TAXOL (TAXOL).

Breastfeeding	Not recommended; paclitaxel likely excreted in breast milk (M/P ratio unknown). Potential for neonatal neutropenia, gastrointestinal toxicity, and developmental effects. Discontinue breastfeeding during therapy and for at least 2 weeks after last dose.
Teratogenic Risk	Paclitaxel is teratogenic in animals; human data limited. First trimester: potential for major malformations (e.g., neural tube defects, skeletal anomalies). Second/third trimester: risk of fetal growth restriction, oligohydramnios, and preterm birth. Avoid in pregnancy unless benefit > risk.

Warnings & precautions

■ FDA Black Box Warning

Anaphylaxis and severe hypersensitivity reactions (including fatal) have occurred. Patients must receive premedication with corticosteroids, diphenhydramine, and H2 antagonists.

Side Effect Profile

Serious Effects

Absolute Contraindications

["History of severe hypersensitivity reactions to paclitaxel or other drugs formulated in Cremophor EL (polyoxyethylated castor oil)","Baseline neutropenia (absolute neutrophil count <1,500 cells/mm³)","Severe hepatic impairment (total bilirubin >5 mg/dL or transaminases >10× ULN for some indications)"]

Clinical Precautions

Precautions

["Hypersensitivity reactions (premedicate as per boxed warning)","Myelosuppression (neutropenia is dose-limiting; monitor blood counts)","Cardiotoxicity (bradycardia, AV block, ventricular tachycardia; caution in patients with cardiac disease)","Peripheral neuropathy (cumulative, may require dose reduction)","Albumin-adjusted bilirubin monitoring for dose adjustments in hepatic impairment","Extravasation (may cause tissue necrosis; avoid extravasation)","Use with caution in patients with prior radiation therapy"]

Clinical Tips & Counseling

Drug interactions

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TAXOL

Clinical safety rating: caution

Comprehensive clinical and safety monograph for TAXOL (TAXOL).

How it works

Paclitaxel stabilizes microtubules by binding to the β-tubulin subunit, preventing depolymerization, thereby disrupting mitotic spindle formation, cell division, and intracellular transport.

What the body does with it

Metabolism	Primarily hepatic metabolism via CYP2C8 and CYP3A4; biliary and fecal excretion; less than 10% excreted renally as unchanged drug.
Excretion	Primarily hepatic metabolism via CYP2C8 and CYP3A4; biliary/fecal excretion accounts for ~70% of total clearance; renal excretion is minimal (<10% as unchanged drug).
Half-life	Terminal elimination half-life is approximately 5.3 to 16.3 hours (mean ~13 hours); exhibits triphasic elimination with a prolonged terminal phase due to extensive tissue binding.
Protein binding	89–98% bound to plasma proteins, primarily to albumin and alpha1-acid glycoprotein.
Volume of Distribution	Large volume of distribution, ranging from 227 to 688 L/m² (approx. 3–10 L/kg), indicating extensive tissue binding and distribution.
Bioavailability	Not available orally due to poor bioavailability (<5%); administered intravenously. Oral formulations under investigation show bioavailability <10%.
Onset of Action	For paclitaxel, onset of clinical effect (e.g., antimitotic activity) is within minutes to hours of intravenous administration; peak plasma concentrations achieved at end of infusion.
Duration of Action	Duration of action is prolonged, with myelosuppression (neutropenia) nadir at 7–14 days, recovery typically by 21 days; schedule-dependent effects require 3-week cycles.

Classification & Brands

Action Class	Antimicrotubule agents- Taxanes
Brand Substitutes	Oncotaxel 100mg Injection, Altaxel 100mg Injection, Cytax 100mg Injection, Mitotax 100mg Injection, Paclitec 100 Injection, Oncotaxel 30mg Injection, Paclistar 30mg Injection, Chemotax 30mg Injection, Paclicad 30mg Injection, Axitaxel 30 Injection

Dosing & administration

Dosage form	INJECTABLE
Renal impairment	No dose adjustment required for mild to moderate renal impairment (CrCl >20 mL/min). For severe renal impairment (CrCl ≤20 mL/min), reduce dose by 25% and monitor closely.
Liver impairment	For Child-Pugh A (bilirubin ≤1.5× ULN and AST/ALT ≤10× ULN): no adjustment. For Child-Pugh B (bilirubin 1.5-3× ULN): reduce dose by 25-50%. For Child-Pugh C (bilirubin >3× ULN): avoid use or reduce dose by 75% with extreme caution.
Pediatric use	Not FDA-approved for pediatric use. In clinical studies, doses of 250-350 mg/m² as a 24-hour infusion every 3 weeks have been used, but safety and efficacy are not established.
Geriatric use	No specific dose adjustment based on age alone. Monitor for increased myelosuppression, neuropathy, and other toxicities. Elderly patients may require dose reduction based on tolerance.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for TAXOL (TAXOL).

Breastfeeding	Not recommended; paclitaxel likely excreted in breast milk (M/P ratio unknown). Potential for neonatal neutropenia, gastrointestinal toxicity, and developmental effects. Discontinue breastfeeding during therapy and for at least 2 weeks after last dose.
Teratogenic Risk	Paclitaxel is teratogenic in animals; human data limited. First trimester: potential for major malformations (e.g., neural tube defects, skeletal anomalies). Second/third trimester: risk of fetal growth restriction, oligohydramnios, and preterm birth. Avoid in pregnancy unless benefit > risk.

Warnings & precautions

■ FDA Black Box Warning

Anaphylaxis and severe hypersensitivity reactions (including fatal) have occurred. Patients must receive premedication with corticosteroids, diphenhydramine, and H2 antagonists.