What is a Generic Drug?

A generic drug is a copy of the brand-name drug with the same dosage, safety, strength, quality, consumption method, performance, and intended use. Before generics become available on the market, the generic company must prove it has the same active ingredients as the brand-name drug and works in the same way and in the same amount of time in the body.

The only differences between generics and their brand-name counterparts is that generics are less expensive and may look slightly different (eg. different shape or color), as trademarks laws prevent a generic from looking exactly like the brand-name drug.

Generics are less expensive because generic manufacturers don't have to invest large sums of money to develop a drug. When the brand-name patent expires, generic companies can manufacture a copy of the brand-name and sell it at a substantial discount.

Iressa (Gefitinib)


Iressa (Gefitinib)

Prescription Required


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Generic Equivalent - Iressa (Gefitinib)

Prescription Required


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  • Product Details


    IRESSA (Gefitinib) is a chemotherapy medication that can be prescribed to treat a certain type of lung cancer. IRESSA is approved to treat metastatic non-small cell lung cancer (NSCLC) with EGFR exon 19 deletions or exon 21 (L858R) substitution mutations.


    The normal IRESSA dosage is 250 mg once daily until the disease becomes worse or the side effects of the drug are not tolerable.

    Take IRESSA exactly as prescribed by the oncologist.

    Do not take a missed dose if the next scheduled dose is 12 hours or less away.


    The active ingredient in IRESSA is gefitinib.

    Gefitinib is a tyrosine kinase inhibitor (TKI) that blocks the activity of a cell receptor called an epidermal growth factor receptor (EGFR). EGFR contributes to the overactive replication of cancer cells, and by blocking its activity, IRESSA prevents the growth of some cancerous cells.

    Fact Table







    Legal status

    RX Only

    Chemical Name


    Elimination half-life

    6-49 hours

    Dosage (Strength)

    250mg (30 tablets)


    Consult a doctor



    Protein binding


    PubChem CID






    ATC code






    Routes of administration



    IRESSA can interact with many other medications. Some examples include:

    • Abametapir
    • Antacids
    • Conivaptan
    • Dabrafenib
    • Enzalutamide
    • Idelalisib
    • Itraconazole
    • Mifepristone
    • Rifampicin
    • Warfarin


    IRESSA (Gefitinib) is for oncology use only. It can only be used under the close supervision of an oncologist.

    IRESSA is a chemotherapeutic agent and has many different side effects and toxicities. Your oncologist should monitor you for the following:

    • Dermatological (skin) toxicity
    • Gastrointestinal toxicity
    • Ocular (eye) toxicity
    • Pulmonary (lung) toxicity

    Side Effects

    IRESSA has many potential side effects. Your oncologist will review these with you before prescribing it. Some of the common ones include:

    • Anorexia
    • Decreased appetite
    • Diarrhea
    • Fatigue
    • Increased liver enzymes
    • Insomnia
    • Nausea
    • Paronychia
    • Proteinuria
    • Pruritus
    • Rash
    • Skin reactors
    • Vomiting
    • Weakness
    • Xeroderma

    Buy IRESSA online with a valid prescription from your healthcare provider. IRESSA is a hazardous medication, so ensure that your doctor knows your plan for obtaining IRESSA online. Purchasing online may be a lower IRESSA price.


    1. Inspra [package insert].New York, NY: Pfizer; 2002.

    Frequently Asked Questions about Iressa (Gefitinib)

    What is Iressa (Gefitinib)?

    Iressa, with the generic name Gefitinib, is a medication used to treat certain types of cancer. It belongs to a class of drugs known as EGFR inhibitors, which work by interfering with the growth and spread of cancer cells in the body.

    What types of cancer is Iressa used to treat?

    Iressa is primarily used for the treatment of non-small cell lung cancer (NSCLC) that has metastasized (spread to other parts of the body). It may also be used for certain breast and other cancers.

    How does Iressa work?

    Iressa works by inhibiting the tyrosine kinase activity of the epidermal growth factor receptor (EGFR), which is a protein involved in the signaling pathways that lead to cancer cell proliferation.

    How is Iressa administered?

    Iressa is administered orally. It's crucial to follow the dosing instructions provided by the healthcare provider.

    What are the side effects of Iressa?

    Common side effects may include diarrhea, skin rash, and other symptoms. It is important to consult with a healthcare provider to understand the full range of possible side effects and to receive guidance on managing them.

    Are there any specific gene mutations that Iressa targets?

    Iressa is particularly effective in treating patients whose tumors have specific mutations in the EGFR gene, namely exon 19 deletions or exon 21 (L858R) substitution mutations.

    Is Iressa a first-line treatment for NSCLC?

    Yes, Iressa is used as a first-line treatment for patients with metastatic non-small cell lung cancer (NSCLC) whose tumors exhibit certain EGFR gene mutations.

    Is Iressa being studied for the treatment of other types of cancer?

    Yes, besides its approved use for NSCLC, Gefitinib is also being studied for its potential in treating other types of cancers.

    Where can I find more information about Iressa?

    Detailed information about Iressa can be obtained from healthcare providers, the FDA, or the manufacturer, AstraZeneca.

    How can I report adverse reactions or quality issues with Iressa?

    Adverse reactions or quality issues can be reported to the FDA's MedWatch Adverse Event Reporting program or to the manufacturer, AstraZeneca.

    IMPORTANT NOTE: The above information is intended to increase awareness of health information and does not suggest treatment or diagnosis. This information is not a substitute for individual medical attention and should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. See your health care professional for medical advice and treatment.

    Product Code : 5477

  • Product Reviews


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