Lapatinib with Lomitapide Interaction Details
Brand Names Associated with Lapatinib
- Lapatinib
- Tykerb®
Brand Names Associated with Lomitapide
- Juxtapid®
- Lomitapide
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 20, 2023
Interaction Effect
Increased exposure of lomitapide
Interaction Summary
The concomitant use of lomitapide (a CYP3A4 substrate) and a weak CYP3A4 inhibitor may cause increased exposure to lomitapide. When the weak CYP3A4 inhibitor, atorvastatin was coadministered with lomitapide, the systemic exposure of lomitapide increased by approximately 2-fold. If concurrent use is required, the maximum lomitapide dosage is 30 mg daily. When initiating a weak CYP3A4 inhibitor in patients already taking lomitapide 10 mg/day or more, decrease the lomitapide dose by 50%. Then carefully titrate based on response and tolerability to a maximum of 30 mg/day.
Severity
Moderate
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
The concomitant use of lomitapide (a CYP3A4 substrate) with a weak CYP3A4 inhibitor may cause increased exposure to lomitapide. If concurrent use is required, the maximum lomitapide dosage is 30 mg daily. When initiating a weak CYP3A4 inhibitor in patients already taking lomitapide 10 mg/day or more, decrease the lomitapide dose by 50%. Then carefully titrate based on response and tolerability to a maximum of 30 mg/day
Mechanism Of Interaction
Inhibition of CYP3A4-mediated lomitapide metabolism
Literature Reports
A) The concomitant administration of the weak CYP3A4 inhibitor atorvastatin 80 mg daily with a single 20-mg dose of lomitapide increased the AUC of lomitapide 2-fold and Cmax 2.1-fold compared with lomitapide administered alone .
Lapatinib Overview
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Lapatinib is used with capecitabine (Xeloda) to treat a certain type of advanced breast cancer in people who have already been treated with other chemotherapy medications. Lapatinib is also used with letrozole (Femara) to treat a certain type of breast cancer in postmenopausal women (women who have experienced a change of life; end of menstrual periods) that has spread to other parts of the body. Lapatinib 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.
Lomitapide Overview
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Lomitapide is used along with diet changes (restriction of cholesterol and fat intake) and other treatments to reduce the amount of low-density lipoprotein (LDL) cholesterol ('bad cholesterol'), total cholesterol, and other fatty substances in the blood in people that have homozygous familial hypercholesterolemia (HoFH; an inherited condition in which cholesterol cannot be removed from the body normally). Lomitapide should not be used to decrease cholesterol levels in people who do not have HoFH. Lomitapide is in a class of medications called cholesterol-lowering medications. It works by slowing the production of cholesterol in the body to decrease the amount of cholesterol that may build up on the walls of the arteries and block blood flow to the heart, brain, and other parts of the body.
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Accumulation of cholesterol and fats along the walls of your arteries (a process known as atherosclerosis) decreases blood flow and, therefore, the oxygen supply to your heart, brain, and other parts of your body. Lowering your blood level of cholesterol and fats may help prevent heart disease, angina (chest pain), strokes, and heart attacks.
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Definitions
Severity Categories
Contraindicated
These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.
Major
This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.
Moderate
This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.
Minor
While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.
Onset
Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.
Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.
Evidence
Level of documentation of the interaction.
Established: The interaction is documented and substantiated in peer-reviewed medical literature.
Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.
How To Manage The Interaction
Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.
It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.
Mechanism Of Interaction
The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.
Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.
Where Does Our Information Come From?
Information for our drug interactions is compiled from several drug compendia, including:
The prescribing information for each drug, as published on DailyMED, is also used.
Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.
The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.