Key facts about Gefitinib
What dosages is Gefitinib available in?
Gefitinib is available as a 250 mg oral tablet.
What is Gefitinib used for?
Gefitinib is an EGFR inhibitor that is used to treat metastatic non-small cell lung cancer (NSCLC) with specific EGFR mutations.
How does Gefitinib work?
Gefitinib targets and blocks certain proteins from attaching to a specific receptor called EGFR. When it blocks EGFR, cancer cells can’t grow and spread as well.
How do I take Gefitinib?
Gefitinib is typically taken as 250 mg by mouth once a day.
Is it safe for me to take Gefitinib?
Gefitinib is a safe and effective treatment when used for FDA licensed indications. However, like all medications, they may give you unwanted side effects. You should always discuss potential side effects with your physician to ensure the medication is suitable and right for you.
Gefitinib Common Side Effects
Common side effects of Gefitinib:
- Rash, acne, and other skin reactions
- Labs suggesting liver irritation
- Build up of protein in the urine
- Diarrhea
- Nausea
- Vomiting
- Weakness
- Lower appetite
Gefitinib Serious Side Effects
Serious side effects are rare with Gefitinib. Contact your healthcare provider immediately if you experience any of the following.
- Serious lung problems: sudden cough, fever, and difficulty breathing
- Damage to the gut: fevers, chills, nausea, vomiting, feeling bloated, intense stomach pain
Serious skin reactions: painful blisters, skin wounds, peeling skin - Serious liver problems: upper stomach pain, yellow skin, yellow around the whites of the eyes
Effects of other drugs, drug classes and over-the-counter products on Gefitinib
The following medications may interact with Gefitinib:
- Substances that are inducers of CYP3A4 activity increase the metabolism of Gefitinib and decrease its plasma concentrations. In patients receiving a potent CYP3A4 inducer such as rifampicin or phenytoin, a dose increase to 500 mg daily should be considered in the absence of severe adverse drug reaction, and clinical response and adverse events should be carefully monitored
- International Normalized Ratio (INR) elevations and/or bleeding events have been reported in some patients taking warfarin while on Gefitinib therapy. Patients taking warfarin should be monitored regularly for changes in prothrombin time or INR
- Substances that are potent inhibitors of CYP3A4 activity (eg, ketoconazole and itraconazole) decrease Gefitinib metabolism and increase Gefitinib plasma concentrations. This increase may be clinically relevant as adverse experiences are related to dose and exposure; therefore caution should be used when administering CYP3A4 inhibitors with Gefitinib
Who makes Gefitinib?
Various FDA-approved generic manufacturers
Is Gefitinib safe in pregnancy?
Talk with your provider if you’re pregnant or thinking about becoming pregnant. Gefitinib hasn’t been well-studied in human pregnancies, but animal studies show that Gefitinib might cause harm to an unborn baby. If you’re a female who’s able to have babies, you should use birth control while taking Gefitinib and for at least two weeks after the last dose. Let your provider know right away if you become pregnant while taking Gefitinib.













