Palbociclib
Rx Only
Generic NamePalbociclib
Therapeutic ClassCDK4/6 Inhibitor
Common Dose125 mg once daily
Max / 24h125 mg
PregnancyCategory D
Indications ▼
Hormone receptor-positive (HR+), HER2-negative advanced or metastatic breast cancer
Used in combination with an aromatase inhibitor or fulvestrant for postmenopausal women
Mechanism & Pharmacokinetics ▼
Mechanism: Selectively inhibits cyclin-dependent kinases 4 and 6 (CDK4/6), preventing phosphorylation of retinoblastoma protein, thereby halting cell cycle progression from G1 to S phase and inhibiting tumor cell proliferation.
Pharmacokinetics: Well absorbed orally; peak plasma concentration ~6–12 hours. Metabolized primarily via CYP3A. Half-life ~29 hours. Excreted mainly in feces; dose adjustment needed in hepatic impairment.
Dosage & Administration ▼
| Patient Category | Recommended Dose | Max / 24h |
|---|---|---|
| Adults (HR+, HER2− Breast Cancer) | 125 mg orally once daily for 21 consecutive days followed by 7 days off (28-day cycle) | 125 mg |
| Elderly | Same as adults; monitor hematologic parameters | 125 mg |
| Hepatic Impairment | Moderate: 75 mg daily; Severe: avoid use | 75 mg (if moderate) |
| Renal Impairment | Mild–Moderate: 125 mg daily; Severe: monitor carefully | 125 mg |
Note: Swallow capsules whole with water. Can be taken with or without food. Avoid grapefruit or grapefruit juice. Monitor blood counts regularly.
Side Effects ▼
Common: Neutropenia, leukopenia, fatigue, nausea, alopecia
Occasional: Anemia, infections, stomatitis, diarrhea
Rare: Pulmonary embolism, hepatotoxicity, QT prolongation
Contraindications ▼
Known hypersensitivity to palbociclib
Severe neutropenia
Pregnancy (unless benefits outweigh risks)
Drug Interaction ▼
Strong CYP3A inhibitors (e.g., ketoconazole) increase plasma levels
Strong CYP3A inducers (e.g., rifampin) reduce effectiveness
Care with concomitant myelosuppressive agents
Pregnancy & Lactation ▼
Category D; can cause fetal harm
Not recommended during breastfeeding
Clinical / Research Summary ▼
Improves progression-free survival in HR+, HER2− advanced breast cancer.
Generally well tolerated; myelosuppression is the primary dose-limiting toxicity.
Used in combination with endocrine therapy for better clinical outcomes.
Patient Counseling Points ▼
Take exactly as prescribed; maintain the 21-days-on, 7-days-off cycle.
Monitor complete blood counts before each cycle.
Report signs of infection, unusual bleeding, or severe fatigue.
Avoid grapefruit juice and notify physician of all medications.
Storage & Handling ▼
Store at 20–25°C
Protect from moisture and light
Keep out of reach of children
Brand Names (Bangladesh & Global) ▼
![Cykin® 125 mg](https://static.remedive.com/item/image/165967731062ecaa7ecbde9.jpg?1659677310")
Cykin® 125 mg
Medical Disclaimer: This clinical summary is for informational purposes only. Always consult a qualified healthcare professional before prescribing or using this medication.
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