Cancer Home > Drug Interactions With Lapatinib
The following sections explain in detail the potentially negative interactions that can occur when lapatinib is combined with any of the drugs listed above.
If you have had high doses of anthracyclines, taking lapatinib may increase your risk of heart problems, including heart failure or an irregular heart rhythm called QT prolongation. Your healthcare provider may need to monitor your heart closely if this is the case.
Certain Antibiotics or Antifungals
Certain antibiotics or antifungals can increase the level of lapatinib in your blood, possibly increasing your risk of side effects of lapatinib. In addition, combining some antibiotics with lapatinib can increase the risk of a dangerous irregular heart rhythm called QT prolongation. Talk to your healthcare provider before taking lapatinib with any antibiotics or antifungal medications. Depending on the particular medication and your situation, your healthcare provider may recommend a decreased lapatinib dosage or suggest that you not take these medications together.
Certain Seizure Medications
Some seizure medications can greatly decrease the level of lapatinib in your blood, perhaps making it less effective. Talk to your healthcare provider before using lapatinib with seizure medications.
Medications That Prolong the QT Interval
Lapatinib prolongs the QT interval, which means that it may increase the risk of a life-threatening irregular heart rhythm. In general, you should not take lapatinib with other medications that can also prolong the QT interval.
Nefazodone may increase the level of lapatinib in your blood, possibly increasing your risk of side effects. Your healthcare provider may suggest a lower lapatinib dose to prevent drug interactions from occurring.