Managing side effects of targeted therapy

Possible side effects

Although targeted therapy may do less damage to healthy cells than chemotherapy, it can still have side effects. These vary for each person. Some people have only a few mild side effects, while others may have more.

Skin problems are a common side effect of targeted therapy.

Different drugs may cause:

• sensitivity to sunlight, skin redness, swelling and dry, flaky skin
• a rash that looks like acne or pimples on the face, scalp or upper body (acneiform rash)
• a skin reaction on the palms and soles, which may include redness, burning, pain, skin peeling and blistering, and thickened skin (called hand–foot syndrome).

Other side effects may include:

• fever
• tiredness
• joint aches
• nausea
• headaches
• dry or itchy eyes with or without blurred vision
• diarrhoea and constipation
• bleeding and bruising
• high blood pressure.

Less commonly, some targeted therapy drugs can affect the way the heart, thyroid or liver work, or increase the risk of getting an infection. It may also cause inflammation of the lungs (pneumonitis). If left untreated, some side effects can become serious.

Why it’s important to report side effects

Some rare side effects, such as heart and lung problems, can become serious and even life-threatening if not treated. It is important to tell your treatment team about any new or worsening side effects. Ask the doctor or nurse which side effects to look out for or report, and who to contact (including after hours).

Some people worry about telling their doctor about side effects because they don’t want to stop the treatment, but most side effects can be better managed when they are reported early.

Your doctor may be able to prescribe medicine to prevent or reduce side effects. In some cases, you may need to take a break from treatment to prevent side effects becoming too serious and causing long-term damage.

Often, when side effects are managed before they become too severe, treatment can continue again once things have improved. At times, taking the drug at a lower dose will still be effective and can prevent the side effects from returning.

Managing side effects

Targeted therapy side effects can begin within days of starting treatment, but more often they occur weeks or even months later.

Most side effects are temporary, lasting from a few weeks to a few months, and will gradually improve over time or once you stop taking the drug. In rare cases, however, some side effects may be permanent.

Your treatment team can help you manage any side effects of targeted therapy, which often need a different approach to side effects from other cancer treatments. For example, skin problems from targeted therapy may be more severe or last longer than skin problems from chemotherapy, and you may be prescribed an antihistamine or steroid cream to help with the itching and dryness.

In some cases, your treatment team will modify the dose of the targeted therapy drug to see if that helps ease the side effects.