Lapatinib (Tykerb®)

Store your medication in the original container with the label. If you want to use a pillbox, talk to your pharmacist. Keep it in a dry place at room temperature unless your provider or pharmacist tells you otherwise. Keep containers out of reach of children and pets.

If a caregiver prepares your dose for you, they should consider wearing gloves or pour the pills directly from their container into the cap, a small cup, or directly into your hand. They should avoid touching the pills. They should always wash their hands before and after giving you the medication. Pregnant or nursing people should not prepare the dose for you. Ask your provider where to return any unused medication for disposal. Do not flush down the toilet or throw in the trash. 

Some cancer medications are only available through specialty pharmacies. Your provider or pharmacist will start this process. Your insurance plan may also affect where you can get your medication.  Call your prescription plan provider to find out which specialty pharmacies are in-network.

This medication may be covered by your prescription plan. If you qualify, you may be able to get financial help through patient assistance programs (PAP). Co-pay cards may also be available to lower your out-of-pocket cost if you have commercial (not Medicare/Medicaid/Tricare) insurance. Your pharmacist, social worker, or navigator can help find resources for financial support.

These are some of the most common or most serious side effects of this medication. Talk with your provider about the side effects you are having and how they can be managed.

This medication can cause liver toxicity, or liver problems, which your provider may monitor for with blood tests called liver function tests. Symptoms may be:

• Yellowing of your skin or eyes.
• Dark or brown urine.
• Pain in your abdomen (belly).

Tell your provider if you have any of these symptoms.

Diarrhea can be a serious side effect that can lead to dehydration (when you do not have enough fluid in your body). Tell your healthcare provider if you have diarrhea.

Diarrhea is when you pass three or more stools in a day. Your providers can suggest medications to relieve diarrhea. Do not take any medications to manage your diarrhea without talking to your provider first because your stool may need to be tested. To manage it, try eating foods that are low in fiber and bland, like white rice and boiled or baked chicken. Try not to eat raw fruits, vegetables, whole grain breads, cereals, and seeds. Soluble fiber is a type of fiber found in some foods that helps absorb (soak up) fluid. Foods high in soluble fiber are applesauce, bananas (ripe), canned fruit, oranges, boiled potatoes, white rice, foods made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Stay hydrated by drinking 8 to 10 glasses of non-alcoholic, non-caffeinated fluid each day.

Talk to your providers if you have nausea and/or vomiting. They can prescribe medications to help you. Making changes to your diet can also help. Avoid things that make your symptoms worse, like heavy or greasy/fatty foods and spicy or acidic foods, like tomatoes, lemons, and oranges. Try saltines or ginger ale to help your symptoms.  

Call your providers if you cannot keep fluids down for more than 12 hours or if you feel lightheaded or dizzy.

The medication may cause skin and nail changes. These side effects are common and can often be managed by making changes in how you care for your skin and nails. 

Skin Changes 
You may have a rash that looks like acne, but it is not acne and should not be treated with acne products. The rash can be:

• Red, swollen, dry, or crusty.
• Sore or tender.
• Itchy or flaky.
• Your skin may also be very dry and can crack, peel, or feel scaly.

This rash often starts in the first week of treatment, but it can happen at any time.
Your provider may prescribe tetracycline (an antibiotic) and a topical (goes on your skin) steroid cream to help lessen skin irritation.

How to Take Care of Your Skin

• Moisturize your skin at least twice a day with a thick, alcohol-free lotion or cream, especially after bathing.
• Protect your skin from the sun by using sunscreen (SPF 30 or higher), wearing a hat and sunglasses, and avoiding direct sunlight.
• Bathe or shower in lukewarm water (not hot) and gently pat your skin dry.
• Use gentle, fragrance-free soaps, lotions, and laundry products.
• Wear gloves when doing housework, dishes, or gardening.
• Drink plenty of water.
• Try not to scratch your skin. 
• Call your provider if you get a rash – they can suggest or prescribe creams or pills to reduce symptoms.
• Call right away if your skin blisters or peels.

Nail and Cuticle Changes (Paronychia)
This medication may also cause changes to the skin around your fingernails and toenails. This is called paronychia.
You might have:

• Red, swollen, or painful skin around your nails.
• Small cuts or cracks (like paper cuts) near your nails or knuckles.
• Nails becoming thick, having ridges, or falling off.

These changes might not go away after treatment, or they may start months after you start treatment.
How to Take Care of Your Nails

• Follow the same skin care tips listed above.
• Don’t bite your nails or cut your cuticles.
• Keep nails clean and dry.
• You can use regular nail polish, but avoid fake nails (like gels, acrylics, or overlays).
• Tell your provider if your nails fall off, become painful, or if you notice any changes or discomfort.

Fatigue can cause exhaustion, feeling worn out and that your body is "heavy" and hard to move, or being unable to focus. It is common when you have cancer, and it is not the same as feeling tired. You may need to adjust your schedule to manage fatigue. Plan times to rest during the day and save your energy for more important activities. Exercise can help lessen fatigue. Talk to your providers about ways to deal with this side effect.

Nutrition is an important part of your care. Cancer treatment can affect your appetite and make it hard to eat. Ask your provider about nutrition counseling services. Some tips you can follow are:

• Try to eat five or six small meals or snacks during the day, instead of 3 larger meals.
• Nutritional supplements may help if you are not eating enough.
• You may have a metallic taste or find that food has no taste. You may dislike foods or beverages that you liked before cancer treatment. These symptoms can last for months or longer after treatment ends.
• Avoid any food that you think smells or tastes bad. If red meat is a problem, eat chicken, turkey, eggs, dairy products, and fish without a strong smell. Sometimes cold food has less of an odor.
• Add extra flavor to meat or fish by marinating it in sweet juices, sweet and sour sauce, or dressing.
• Use seasonings like basil, oregano, or rosemary to add flavor.

This medication can cause inflammation (swelling and irritation) of your lungs, called pneumonitis. It can also cause scarring of your lungs, called interstitial lung disease. If you have any new or worsening symptoms, like shortness of breath, cough (with or without mucous), fever, or chest pain, call your provider right away. If you are finding it hard to breathe, call 911 right away.

This medication can cause or worsen pre-existing heart problems, like congestive heart failure, restrictive cardiomyopathy, decreased heart function, and heart attack. Symptoms may be:

• Sudden weight gain.
• Swelling in your ankles or legs.
• Chest pain or pressure.
• Pain in your left arm, back, or jaw.
• Sweating.
• Shortness of breath.
• Clammy skin.
• Nausea.
• Dizziness or lightheadedness.

If you have any of these symptoms, call 911.

QT prolongation is when your heart is not working how it should, and it can cause slow or abnormal heartbeats or an abnormal heart rhythm. Tell your provider right away if you feel abnormal heartbeats or if you feel dizzy or faint.