Drug Interactions between gefitinib and TPOXX
This report displays the potential drug interactions for the following 2 drugs:
- gefitinib
- TPOXX (tecovirimat)
Interactions between your drugs
gefitinib tecovirimat
Applies to: gefitinib and TPOXX (tecovirimat)
MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of gefitinib, which is primarily metabolized by the isoenzyme. When a single 500 mg dose of gefitinib was administered following pretreatment with the potent CYP450 3A4 inducer rifampin (600 mg once daily for 16 days) in healthy male volunteers, mean gefitinib systemic exposure (AUC) decreased by 83% compared to administration of gefitinib alone. The interaction has not been studied with other, less potent inducers.
MANAGEMENT: The potential for diminished pharmacologic effects of gefitinib should be considered during coadministration with CYP450 3A4 inducers. Pharmacologic response to gefitinib should be monitored more closely whenever a CYP450 3A4 inducer is added to or withdrawn from therapy, and the gefitinib dosage adjusted as necessary.
References (5)
- Li J, Zhao M, He P, Hidalgo M, Baker SD (2007) "Differential metabolism of gefitinib and erlotinib by human cytochrome p450 enzymes." Clin Cancer Res, 13, p. 3731-7
- (2023) "Product Information. Iressa (gefitinib)." Astra-Zeneca Pharmaceuticals
- (2022) "Product Information. Apo-Gefitinib (gefitinib)." Apotex Inc
- (2023) "Product Information. Iressa (gefitinib)." AstraZeneca UK Ltd
- (2021) "Product Information. Iressa (gefitinib)." AstraZeneca Pty Ltd
Drug and food interactions
tecovirimat food
Applies to: TPOXX (tecovirimat)
ADJUST DOSING INTERVAL: Food may increase the extent of tecovirimat absorption following oral administration. When the recommended oral dose of tecovirimat (600 mg every 12 hours) was administered with a meal (approximately 600 calories and 25 g of fat) in healthy adults weighing less than 120 kg, tecovirimat absorption increased by 39% relative to fasting.
MANAGEMENT: Oral tecovirimat should be taken within 30 minutes after a full meal containing moderate or high fat (approximately 600 calories and 25 g of fat) with 6 to 8 ounces of water.
References (1)
- "Product Information. Tpoxx (tecovirimat)." SIGA Technologies, Inc.
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
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. | |
No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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