Vitamin E - Ibrance (Palbociclib) Interaction
Herbal: Vitamin E
Also Known As: Alpha-tocopherol, Beta-tocopherol, Delta-tocopherol, Gamma-tocopherol
Drug: Palbociclib
Brand names:
Ibrance

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Palbociclib is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates
Theoretically, vitamin E might induce metabolism of CYP3A4, possibly reducing the levels CYP3A4 substrates.
Vitamin E appears to bind with the nuclear receptor, pregnane X receptor (PXR), which results in increased expression of CYP3A4. Although the clinical significance of this is not known, use caution when considering concomitant use of vitamin E and other drugs affected by these enzymes.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
References
- Landes N, Pfluger P, Kluth D, et al. Vitamin E activates gene expression via the pregnane X receptor. Biochem Pharmacol 2003;65:269-73. .
- Brigelius-Flohe R. Vitamin E and drug metabolism. Biochem Biophys Res Commun 2003;305:737-40.
Vitamin E Overview

Palbociclib Overview
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Palbociclib is used in combination with anastrozole (Arimidex), exemestane (Aromasin), or letrozole (Femara) to treat a certain type of hormone receptor–positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) or breast cancer that has spread to other parts of the body in women who have experienced menopause (change of life; end of monthly menstrual periods) or in men. Palbociclib is also used along with fulvestrant (Faslodex) to treat a certain type of hormone receptor–positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) or breast cancer that has spread to other parts of the body in people who have been treated with an antiestrogen medication such as tamoxifen (Nolvadex). Palbociclib is in a class of medications called kinase inhibitors. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps stop or slow the spread of cancer cells.
Vitamin E - More Interactions
Vitamin E interacts with 742 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
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Drug descriptions are provided by MedlinePlus.