What is Dacomitinib: Uses, Dosage, Side Effects and More

Dacomitinib is a targeted cancer medication that helps treat a specific type of non-small cell lung cancer. This oral medication works by blocking certain proteins that fuel cancer cell growth, offering hope for patients whose tumors have particular genetic changes. Understanding how this medication works and what to expect can help you feel more prepared and confident about your treatment journey.

What is Dacomitinib?

Dacomitinib is a prescription medication that belongs to a class of drugs called tyrosine kinase inhibitors. It's specifically designed to treat non-small cell lung cancer (NSCLC) that has spread to other parts of the body or cannot be removed by surgery. This medication targets cancer cells that have specific genetic mutations, making it a personalized treatment approach.

The drug works by blocking proteins called EGFR (epidermal growth factor receptor) that send signals telling cancer cells to grow and multiply. By interrupting these signals, dacomitinib helps slow down or stop the cancer from spreading further. This targeted approach means it focuses on cancer cells while affecting normal cells less than traditional chemotherapy.

What is Dacomitinib Used For?

Dacomitinib is primarily used to treat metastatic non-small cell lung cancer in patients whose tumors have specific EGFR gene mutations. Your doctor will test your tumor tissue to confirm you have these mutations before prescribing this medication. This genetic testing ensures the treatment will be most effective for your specific type of cancer.

The medication is typically prescribed when lung cancer has spread beyond the lungs to other parts of your body. It's considered a first-line treatment, meaning it's often one of the first medications your doctor might recommend if you're newly diagnosed with this type of cancer. Your oncologist will determine if dacomitinib is right for your particular situation based on your test results and overall health.

How Does Dacomitinib Work?

Dacomitinib is considered a strong and effective targeted therapy for lung cancer with EGFR mutations. It works by permanently binding to the EGFR protein on cancer cells, which is different from some other similar medications that bind temporarily. This permanent binding can make it more effective at stopping cancer cell growth over time.

Think of EGFR proteins as switches that turn on cancer cell growth. Dacomitinib acts like a lock that permanently turns off these switches, preventing cancer cells from receiving the signals they need to multiply. This targeted approach helps preserve more of your healthy cells compared to traditional chemotherapy, though you may still experience side effects.

The medication also blocks other related proteins in the same family, which can help prevent cancer cells from finding alternative ways to grow. This broader blocking action may help the treatment remain effective longer than some other targeted therapies.

How Should I Take Dacomitinib?

Take dacomitinib exactly as your doctor prescribes, usually once daily on an empty stomach. The most important thing is to take it at the same time each day, either one hour before eating or two hours after eating. This consistent timing helps your body absorb the medication properly and maintain steady levels in your system.

Swallow the tablet whole with a full glass of water. Don't crush, chew, or break the tablet, as this can affect how the medication works in your body. If you have trouble swallowing pills, talk to your healthcare team about strategies that might help, but never alter the tablet itself.

You'll need to avoid certain foods and medications that can interfere with dacomitinib. Grapefruit and grapefruit juice can increase the medication's levels in your blood, potentially causing more side effects. Your doctor will also review all your other medications to make sure there aren't any dangerous interactions.

Regular blood tests will be necessary to monitor how your body is responding to the medication. These tests help your doctor adjust your dose if needed and watch for any concerning changes in your blood counts or organ function.

How Long Should I Take Dacomitinib For?

You'll typically continue taking dacomitinib as long as it's helping control your cancer and you're tolerating the side effects reasonably well. This might be months or even years, depending on how your cancer responds to treatment. Your oncologist will monitor your progress through regular scans and blood tests to determine if the medication is still working effectively.

Treatment duration varies significantly from person to person. Some people take dacomitinib for many months with good cancer control, while others may need to switch to different treatments sooner. Your doctor will work with you to find the right balance between controlling your cancer and managing any side effects you experience.

Never stop taking dacomitinib suddenly or change your dose without talking to your healthcare team first. Even if you're feeling better, the medication may still be working to control cancer cells you can't see or feel. Your doctor will guide you through any dose adjustments or treatment changes based on your individual response and test results.

What Are the Side Effects of Dacomitinib?

Like all cancer medications, dacomitinib can cause side effects, though not everyone experiences them the same way. The most common side effects are manageable with proper care and monitoring from your healthcare team. Understanding what to expect can help you feel more prepared and know when to reach out for support.

Here are the most common side effects you might experience:

• Diarrhea, which can range from mild to severe
• Skin and nail changes, including rash, dry skin, and nail problems
• Mouth sores or inflammation
• Loss of appetite and weight loss
• Fatigue and general weakness
• Nausea and vomiting

These common side effects are usually manageable with medications and lifestyle adjustments. Your healthcare team will provide specific guidance on managing each symptom you experience.

Some people may experience more serious but less common side effects that require immediate medical attention:

• Severe lung problems, including inflammation or scarring
• Serious skin reactions that cover large areas of your body
• Eye problems, including corneal inflammation or perforation
• Severe liver problems
• Heart rhythm changes

While these serious side effects are rare, it's important to know the warning signs and contact your doctor immediately if you experience severe breathing problems, widespread skin reactions, eye pain or vision changes, or unusual heart rhythms.

Who Should Not Take Dacomitinib?

Dacomitinib isn't suitable for everyone, and your doctor will carefully evaluate whether it's safe for you. People with certain health conditions or circumstances may need to avoid this medication or require special monitoring. Your healthcare team will review your complete medical history before prescribing dacomitinib.

You should not take dacomitinib if you're allergic to it or any of its ingredients. Tell your doctor about any previous allergic reactions to medications, especially other cancer treatments. Your doctor will also need to know about all your current health conditions and medications to ensure dacomitinib is safe for you.

Women who are pregnant or breastfeeding should not take dacomitinib, as it can harm a developing baby. If you're able to become pregnant, you'll need to use effective birth control during treatment and for at least 17 days after your last dose. Men taking dacomitinib should also use contraception if their partner could become pregnant.

People with severe kidney or liver problems may need dose adjustments or might not be able to take dacomitinib safely. Your doctor will run blood tests to check your organ function before starting treatment and continue monitoring throughout your therapy.

Dacomitinib Brand Name

Dacomitinib is sold under the brand name Vizimpro. This is the only brand name currently available for this medication in the United States. When you pick up your prescription, you'll see "Vizimpro" on the bottle label, which is the same medication as dacomitinib.

Always make sure you're receiving the correct medication by checking both the generic name (dacomitinib) and brand name (Vizimpro) with your pharmacist. This helps prevent any confusion or medication errors, especially if you're taking multiple cancer treatments.

Dacomitinib Alternatives

Several other medications work similarly to dacomitinib for treating EGFR-positive lung cancer. These alternatives include erlotinib (Tarceva), gefitinib (Iressa), afatinib (Gilotrif), and osimertinib (Tagrisso). Each of these medications targets EGFR proteins but may work slightly differently or be appropriate for different situations.

Your doctor chooses the best medication based on your specific genetic test results, previous treatments, and overall health. Some alternatives might be better if you develop resistance to dacomitinib, while others might be preferred as first-line treatments depending on your tumor's characteristics.

If dacomitinib stops working or causes too many side effects, your oncologist can discuss switching to one of these alternatives. Each medication has its own side effect profile and effectiveness, so there are often good options available if you need to change treatments.

Is Dacomitinib Better Than Erlotinib?

Clinical studies suggest that dacomitinib may be more effective than erlotinib for some patients with EGFR-positive lung cancer. Research shows that people taking dacomitinib often have longer periods before their cancer progresses compared to those taking erlotinib. However, dacomitinib also tends to cause more side effects than erlotinib.

The choice between these medications depends on your individual situation, including your specific genetic mutations, overall health, and ability to tolerate side effects. Some patients do better with erlotinib because they experience fewer side effects, while others benefit more from dacomitinib's stronger cancer-fighting effects.

Your oncologist will consider all these factors when recommending the best treatment for you. Both medications are effective options, and the "better" choice varies from person to person based on their unique circumstances and treatment goals.