Drug interactions between dexamethasone and Tykerb
| Results for the following 2 drugs: |
|---|
| dexamethasone |
| Tykerb (lapatinib) |
Interactions between your selected drugs
dexamethasone ↔ lapatinib
Applies to:dexamethasone and Tykerb (lapatinib)
GENERALLY AVOID: Coadministration with potent inducers of CYP450 3A4 may significantly decrease the plasma concentrations of lapatinib, which is primarily metabolized by the isoenzyme. In healthy subjects, administration of lapatinib in combination with the CYP450 3A4 inducer carbamazepine (100 mg twice daily for 3 days, then 200 mg twice daily for 14 days) resulted in a 72% reduction of lapatinib systemic exposure (AUC) compared to control.
MANAGEMENT: The use of lapatinib in combination with potent CYP450 3A4 inducers such as carbamazepine, dexamethasone, phenobarbital, phenytoin, rifamycins, and St. John's wort should generally be avoided. If concomitant use is unavoidable, the manufacturer recommends titrating the lapatinib dosage gradually from 1250 mg/day up to 4500 mg/day depending on patient tolerability. Based on pharmacokinetic studies, this dosage is predicted to adjust the lapatinib systemic exposure (AUC) to the range observed without inducers. However, clinical data are lacking. The dosage should be reduced to the indicated dosage following discontinuation of the potent CYP450 3A4 inducer. Other known inducers include aminoglutethimide, barbiturates, bexarotene, bosentan, efavirenz, etravirine, nevirapine, somatrem, somatropin, and various other anticonvulsants, although the extent to which they interact with lapatinib is unknown.
See also...
Drug Interaction Classification
The classifications below are a guideline only. The relevance of a particular drug interaction to a specific patient is difficult to determine using this tool alone given the large number of variables that may apply.
| Major | Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. |
| Moderate | Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. |
| Minor | Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. |
Do not stop taking any medications without consulting your healthcare provider.
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