1. Clinical & Scientific Overview
Palbociclib (TIP-MED-000573, Reference Code [ONC-24]) is classified under
Oncology & Antineoplastic Medicines as a Targeted Therapy (CDK4/6 Cell-Cycle Inhibitor) • Reversible Selective Cyclin-Dependent Kinase 4 and 6 (CDK4/6) Inhibitor.
Within the Indian regulatory and compendial framework, it is governed under Schedule H (Prescription Only — Specialist Oncology Supervision).
Ibrance (Pfizer Ltd), Palbace (Pfizer India), Palbonix (Beacon / Special Access)
Capsule / Film-Coated Tablet: 75 mg, 100 mg, 125 mg
Oncology Specialisation & Cytotoxic Safety Protocol
Targeted Therapy (CDK4/6 Cell-Cycle Inhibitor)
Antineoplastic Targeted Agent
Standard Regimen & Cycle Context: 125 mg orally once daily on Days 1–21 followed by 7 days off-treatment (28-day cycle).
Signature Dose-Limiting Toxicities & Organ Monitoring: High incidence of Grade 3/4 Neutropenia (~65%), which occurs via reversible bone marrow cell-cycle cytostasis (unlike cytotoxic chemotherapy apoptosis, febrile neutropenia is uncommon <2% and resolves rapidly with a 7-day drug holiday and dose reduction to 100 mg or 75 mg without routine G-CSF); rare drug-induced ILD/pneumonitis.
Extravasation, Premedication & Safe Cytotoxic Handling: Check Complete Blood Count (CBC with ANC) on Day 1 and Day 15 of the first two cycles, and on Day 1 of subsequent cycles; hold dose if ANC <1,000/mm3.
3. Mechanism of Action & Pharmacodynamics
Inhibits CDK4 and CDK6 complexes with Cyclin D1, preventing phosphorylation of the Retinoblastoma (Rb) tumour suppressor protein and arresting hormone receptor-positive breast cancer cells at the G1-to-S phase cell-cycle restriction point.
4. Therapeutic Indications & Evidence-Supported Uses
- HR-positive, HER2-negative advanced or metastatic Breast Cancer in combination with an Aromatase Inhibitor (Letrozole) or Fulvestrant
🇮🇳 Jurisdiction & Indication Note: Indications and schedules reflect Indian compendial and regulatory records (CDSCO / Indian Pharmacopoeia & NFI / NLEM 2022). Where international reference labels (US FDA DailyMed / NCBI StatPearls) are cited for pharmacokinetic or mechanistic parameters, international approvals do not automatically imply CDSCO approval in India.
5. Educational Dosage Context, Formulations & Administration
Educational Dosing & Regimen Summary: Educational Oncology Regimen Context (Specialist Reference Only): 125 mg orally once daily on Days 1–21 followed by 7 days off-treatment (28-day cycle).
Administration & Meal Timing: 125 mg orally once daily on Days 1–21 followed by 7 days off-treatment (28-day cycle).
6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment
Specialist oncology pharmacokinetic profile; dosing depends on Body Surface Area (BSA in m2), Calvert GFR formula, or flat targeted dosing with strict organ-function adjustments.
Hepatic enzymatic activation/inactivation or proteolytic degradation (for monoclonal antibodies); see specific polymorphism and interaction notes.
Verify serum creatinine and eGFR before every cycle; see drug-specific renal dosing and uroprotection rules.
Check total bilirubin, AST, and ALT prior to each cycle; taxanes, anthracyclines, and TKIs require strict hepatic dose modification.
7. Contraindications, Precautions & High-Risk Warnings
- Severe hypersensitivity to Palbociclib or formulation vehicle
- Pregnancy and lactation (potent teratogen/embryotoxic class warning unless explicitly evaluated by oncology specialist)
- Severe unrecovered bone marrow aplasia or decompensated organ failure per protocol thresholds
Key Clinical Precautions: High incidence of Grade 3/4 Neutropenia (~65%), which occurs via reversible bone marrow cell-cycle cytostasis (unlike cytotoxic chemotherapy apoptosis, febrile neutropenia is uncommon <2% and resolves rapidly with a 7-day drug holiday and dose reduction to 100 mg or 75 mg without routine G-CSF); rare drug-induced ILD/pneumonitis.
8. Adverse Effects Profile
- High incidence of Grade 3/4 Neutropenia (~65%), which occurs via reversible bone marrow cell-cycle cytostasis (unlike cytotoxic chemotherapy apoptosis, febrile neutropenia is uncommon <2% and resolves rapidly with a 7-day drug holiday and dose reduction to 100 mg or 75 mg without routine G-CSF); rare drug-induced ILD/pneumonitis.
- High incidence of Grade 3/4 Neutropenia (~65%), which occurs via reversible bone marrow cell-cycle cytostasis (unlike cytotoxic chemotherapy apoptosis, febrile neutropenia is uncommon <2% and resolves rapidly with a 7-day drug holiday and dose reduction to 100 mg or 75 mg without routine G-CSF); rare drug-induced ILD/pneumonitis.
9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions
- High incidence of Grade 3/4 Neutropenia (~65%), which occurs via reversible bone marrow cell-cycle cytostasis (unlike cytotoxic chemotherapy apoptosis, febrile neutropenia is uncommon <2% and resolves rapidly with a 7-day drug holiday and dose reduction to 100 mg or 75 mg without routine G-CSF); rare drug-induced ILD/pneumonitis.
- Avoid live-attenuated vaccines during immunosuppressive chemotherapy; verify CYP3A4, UGT1A1, DPD, and QTc interactions before each cycle.
10. Clinical Monitoring, Patient Counselling & Storage
Clinical & Laboratory Monitoring: Check Complete Blood Count (CBC with ANC) on Day 1 and Day 15 of the first two cycles, and on Day 1 of subsequent cycles; hold dose if ANC <1,000/mm3.
Pharmacist Patient Counselling Points:
- Check Complete Blood Count (CBC with ANC) on Day 1 and Day 15 of the first two cycles, and on Day 1 of subsequent cycles; hold dose if ANC <1,000/mm3.
- Report fever >=38.0°C (100.4°F) immediately (medical emergency: possible febrile neutropenia).
- Follow strict reproductive contraception and safe cytotoxic oral handling instructions.
Storage, Stability & Dispensing Safeguards: Check Complete Blood Count (CBC with ANC) on Day 1 and Day 15 of the first two cycles, and on Day 1 of subsequent cycles; hold dose if ANC <1,000/mm3.
11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)
12. Authoritative References, Regulatory Sources & Editorial Disclaimer
Primary Compendial & Guideline Reference: National Cancer Grid (NCG) India Consensus Guidelines; NLEM 2022 Antineoplastic Section; Indian Pharmacopoeia (IP) & CDSCO Approved Oncology Prescribing Information.
Official Verification Portals: National Cancer Grid (NCG) India — Evidence-Based Oncology Guidelines • CDSCO — Central Drugs Standard Control Organization Approved Drug Data • Indian Pharmacopoeia Commission (IPC)
Last Medically & Pharmaceutically Reviewed: 2026-11-10 • Verification Status: VERIFIED_EDUCATIONAL_CONTENT
Educational & Clinical Disclaimer: This reference profile is published solely for pharmacy education, academic study, and professional clinical reference. It does not substitute for patient-specific clinical judgement, qualified specialist oncology/medical supervision, or official CDSCO/IP prescribing information. Never self-medicate with prescription, Schedule H/H1/X, NDPS, or oncology medicines.
13. Related Reference Monographs, Educational Guides & Visual Concept
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