Palbociclib Dosage

Medically reviewed by Drugs.com. Last updated on Mar 28, 2025.

Usual Adult Dose for Breast Cancer

28-day cycle: 125 mg orally once a day for 21 consecutive days followed by 7 days off

Comments:

• Administer the recommended dose of an aromatase inhibitor when given with this drug. Refer to the prescribing information for the aromatase inhibitor being used.
• When given with this drug, the recommended dose of fulvestrant is 500 mg on Days 1, 15, 29, and once monthly thereafter. Refer to the prescribing Information for fulvestrant.
• Pre/perimenopausal women treated with the combination of this drug plus fulvestrant should be treated with luteinizing hormone-releasing hormone (LHRH) agonists according to local protocol.

Use: For the treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer in combination with an aromatase inhibitor as initial endocrine-based therapy in postmenopausal women OR fulvestrant in women with disease progression following endocrine therapy

Renal Dose Adjustments

Mild/Moderate/Severe renal impairment (CrCl greater than 15 mL/min): No adjustment recommended.

Liver Dose Adjustments

• Mild/Moderate (Child-Pugh A/B) hepatic impairment: No adjustment recommended.
• Severe (Child-Pugh C) hepatic impairment: 75 mg orally once daily for 21 days followed by 7 days off for a cycle of 28 days

Dose Adjustments

Adverse reactions:

• Starting dose: 125 mg orally once a day
• First dose reduction: 100 mg orally once a day
• Second dose reduction: 75 mg orally once a day
• Discontinue therapy if further dose reduction below 75 mg/day required.

HEMATOLOGIC TOXICITIES except lymphopenia (unless associated with clinical events such as opportunistic infections):
GRADE 1 OR 2: No adjustment recommended.
GRADE 3 OR HIGHER:

• Day 1 of cycle: Withhold therapy; repeat complete blood count monitoring within 1 week. When recovered to Grade 2 or less, start the next cycle at the same dose.
• Day 15 of first 2 cycles: If Grade 3 on Day 15, continue at current dose to complete cycle and repeat complete blood count on Day 22. If Grade 4 on Day 22, see Grade 4 dose modification guidelines. Consider dose reduction in cases of prolonged (more than 1 week) recovery from Grade 3 neutropenia or recurrent Grade 3 neutropenia on Day 1 of subsequent cycles.

GRADE 3 NEUTROPENIA: (Absolute neutrophil count [ANC]: Grade 1: ANC less than LLN 1500/mm 3; Grade 2: ANC 1000 to less than 1500/mm 3; Grade 3: ANC 500 to 1000/mm 3; Grade 4: ANC Less than 500/mm 3) with fever 38.5C or higher and/or infection: At any time withhold therapy until recovery to Grade 2 or less. Resume at the next lower dose.
GRADE 4: Withhold therapy until recovery to Grade 2 or less. Resume at next lower dose.

Non-Hematologic Toxicities:

• Grade 1 or 2: No adjustment recommended.
• Grade 3 or higher (if persisting despite medical treatment): Withhold therapy until symptoms resolve to Grade 1 or less OR Grade 2 or less if not considered a patient safety risk. Resume at next lower dose upon restarting.

Concomitant Use with Strong CYP450 3A Inhibitors:

• Avoid concomitant use if possible or reduce palbociclib dose to 75 mg orally once a day.
• If use of strong CYP450 3A inhibitor discontinued, increase palbociclib dose (after 3 to 5 half-lives of the inhibitor) to the dose used prior to initiation of the inhibitor.

Precautions

CONTRAINDICATIONS:

• None

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• This drug should be taken with food.
• This drug should be taken at approximately the same time each day.
• If a dose is missed, the next dose should be taken at the usual time without doubling up the dose.
• This drug should be swallowed whole; do not chew, crush, or open capsules.
• Capsules should not be ingested if broken, cracked, or otherwise not intact.

Monitoring:

• Hematologic: CBC (prior to treatment initiation, at beginning of each cycle, on Day 14 of first 2 cycles, and as clinically indicated)
• Infections/Infestations: Signs of infection
• Respiratory: Signs of pulmonary embolism, and ILD/pneumonitis
• Grade 1 or 2 neutropenia in the first 6 cycles: Monitor complete blood counts for subsequent cycles every 3 months, prior to the beginning of a cycle and as clinically indicated.

Patient advice:

• Avoid grapefruit, grapefruit juice, and grapefruit products during therapy.
• Advise patients to immediately report new or worsening respiratory symptoms.

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Further information

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