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Palbociclib Dosage

Medically reviewed by Last updated on Mar 28, 2023.

Applies to the following strengths: 75 mg; 100 mg; 125 mg

Usual Adult Dose for Breast Cancer

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


  • 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.
  • 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.



  • None

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

Consult WARNINGS section for additional precautions.


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.

  • 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.

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.