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

Afatinib is a targeted cancer medication that blocks specific proteins helping cancer cells grow and spread. It's a prescription drug primarily used to treat certain types of lung cancer that have particular genetic changes. Think of it as a precise tool that interferes with the cancer's ability to multiply, rather than a general chemotherapy that affects all rapidly dividing cells.

What is Afatinib?

Afatinib belongs to a class of medications called tyrosine kinase inhibitors. It works by blocking certain proteins called EGFR (epidermal growth factor receptor) that fuel cancer cell growth. This medication is specifically designed to target cancer cells with mutations in the EGFR gene, making it a personalized treatment approach.

The drug comes as an oral tablet that you take by mouth, making it more convenient than intravenous chemotherapy treatments. It's manufactured as a targeted therapy, meaning it's designed to attack specific features of cancer cells while potentially causing less damage to healthy cells compared to traditional chemotherapy.

What is Afatinib Used For?

Afatinib is primarily prescribed for treating non-small cell lung cancer (NSCLC) that has specific genetic mutations. Your doctor will test your cancer tissue to determine if you have the EGFR mutations that make afatinib effective for your particular case.

The medication is typically used when your lung cancer has spread to other parts of your body or cannot be removed with surgery. It's often prescribed as a first-line treatment for patients whose tumors have EGFR exon 19 deletions or exon 21 substitution mutations.

In some cases, doctors may also prescribe afatinib for squamous cell carcinoma of the lung, particularly when other treatments haven't been effective. Your oncologist will determine if this medication is appropriate based on your specific cancer type and genetic testing results.

How Does Afatinib Work?

Afatinib works by permanently blocking EGFR proteins that send growth signals to cancer cells. Unlike some other targeted therapies, afatinib binds irreversibly to these proteins, meaning the blockade is long-lasting and potent.

The medication essentially starves cancer cells of the signals they need to grow and divide. When EGFR proteins are blocked, cancer cells struggle to multiply and may eventually die. This targeted approach can slow or stop cancer progression in many patients.

As a relatively strong targeted therapy, afatinib can be quite effective but may also cause more side effects than some other oral cancer medications. The irreversible binding makes it particularly potent against certain types of EGFR mutations.

How Should I Take Afatinib?

Take afatinib exactly as your doctor prescribes, typically once daily on an empty stomach. You should take it at least one hour before eating or three hours after eating to ensure proper absorption.

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. Try to take it at the same time each day to maintain consistent levels in your body.

Avoid eating for at least one hour after taking afatinib. Foods, especially high-fat meals, can significantly reduce how much medication your body absorbs. This timing is crucial for the medication to work effectively.

If you have trouble swallowing tablets, talk to your healthcare team about options. Never dissolve or crush afatinib tablets without specific instructions from your doctor or pharmacist.

How Long Should I Take Afatinib For?

You'll typically continue taking afatinib for as long as it's controlling your cancer and you're tolerating the side effects reasonably well. This could be months or even years, depending on how your cancer responds to treatment.

Your doctor will monitor your progress through regular scans and blood tests to assess how well the medication is working. If your cancer stops responding to afatinib or if side effects become too severe, your oncologist may adjust your treatment plan.

Some patients take afatinib for extended periods with good cancer control and manageable side effects. Others may need to stop sooner due to cancer progression or intolerable side effects. Your treatment duration will be highly individualized based on your response and overall health.

What Are the Side Effects of Afatinib?

Most people taking afatinib experience some side effects, though they vary in severity from person to person. The good news is that many side effects can be managed with supportive care and dose adjustments.

Here are the most common side effects you might experience while taking afatinib:

• Diarrhea (affects most patients but usually manageable)
• Skin rash and acne-like bumps on face and upper body
• Dry, cracked, or peeling skin
• Mouth sores or ulcers
• Nail problems including infection around nails
• Decreased appetite and weight loss
• Fatigue and weakness
• Nausea and vomiting

These common side effects often improve as your body adjusts to the medication. Your healthcare team can provide medications and strategies to help manage these symptoms effectively.

While less common, some patients may experience more serious side effects that require immediate medical attention:

• Severe diarrhea that leads to dehydration
• Serious skin reactions with blistering or peeling
• Lung inflammation causing shortness of breath or cough
• Liver problems causing yellowing of skin or eyes
• Heart problems affecting pumping ability
• Severe eye problems including corneal damage

Contact your healthcare team immediately if you experience any of these serious side effects. Most side effects are manageable with proper medical support and dose adjustments.

Who Should Not Take Afatinib?

Afatinib isn't suitable for everyone, and your doctor will carefully evaluate whether it's safe for you. People with certain health conditions or taking specific medications may need to avoid this treatment.

You should not take afatinib if you're allergic to it or any of its ingredients. Your doctor will also be cautious about prescribing it if you have severe kidney or liver problems, as these organs help process the medication.

Pregnant women should not take afatinib as it can harm the developing baby. If you're of childbearing age, you'll need to use effective contraception during treatment and for at least two weeks after stopping the medication.

People with certain heart conditions, severe lung disease, or active infections may need alternative treatments. Your oncologist will review your complete medical history to determine if afatinib is appropriate for your situation.

Afatinib Brand Names

Afatinib is sold under the brand name Gilotrif in the United States and many other countries. This is the most commonly prescribed form of the medication.

The generic name "afatinib" refers to the active ingredient, while Gilotrif is the brand name used by the manufacturer. Both terms refer to the same medication, so don't be confused if you see either name on your prescription or medical records.

Currently, Gilotrif is the primary brand available, though this may change as patents expire and generic versions potentially become available in the future.

Afatinib Alternatives

Several other targeted therapies are available for treating EGFR-positive lung cancer, each with its own benefits and considerations. Your oncologist will choose the best option based on your specific genetic mutations and medical situation.

Erlotinib (Tarceva) and gefitinib (Iressa) are other EGFR inhibitors that work similarly to afatinib but may have different side effect profiles. These medications might be considered if you can't tolerate afatinib or if your cancer develops resistance.

Osimertinib (Tagrisso) is a newer targeted therapy that's particularly effective for certain EGFR mutations and may cause fewer side effects than afatinib. Your doctor might recommend this as an alternative or subsequent treatment option.

Traditional chemotherapy combinations remain important alternatives, especially if targeted therapies aren't suitable for your cancer type. Immunotherapy drugs may also be options depending on your specific situation and cancer characteristics.

Is Afatinib Better Than Erlotinib?

Both afatinib and erlotinib are effective EGFR inhibitors, but they work slightly differently and may be better suited for different patients. The choice between them depends on your specific cancer mutations and how you tolerate side effects.

Afatinib irreversibly blocks EGFR proteins, while erlotinib's binding is reversible. This means afatinib may be more potent but could also cause more side effects. Studies suggest afatinib might be more effective for certain EGFR mutations, particularly exon 19 deletions.

In terms of side effects, erlotinib may be better tolerated by some patients, with potentially less severe diarrhea and skin problems. However, individual responses vary significantly, and what works best for one person may not be ideal for another.

Your oncologist will consider factors like your specific genetic mutations, overall health, and personal preferences when choosing between these medications. Sometimes patients may try one and then switch to the other based on effectiveness and tolerability.