Targeted Therapy for Basal Cell Carcinoma: Seven Side Effects to Discuss

For some people with advanced basal cell carcinoma (BCC), hedgehog inhibitors offer a treatment option when surgery or radiation isn’t suitable. Vismodegib (Erivedge) and sonidegib (Odomzo) block the hedgehog signaling pathway, a system involved in cell growth that can contribute to cancer when it becomes overactive. These medicines can help control the cancer, but side effects may affect eating, energy, movement and quality of life.

The effects vary from person to person, and many can be managed with help from the treatment team. Reporting new or worsening symptoms early can give clinicians more options to address them. Depending on the situation, the team may discuss supportive care, a temporary break, a different schedule or dose, or another treatment. Don’t change or stop a prescribed medicine without discussing it with your doctor.

Pregnancy is a serious safety concern with these medicines: they can cause severe harm to a fetus, including birth defects or pregnancy loss. People who could become pregnant need clear counseling and must follow the pregnancy-prevention measures recommended by their care team during treatment and for the specified period afterward.

1. Muscle spasms

Spasms are among the common side effects of hedgehog inhibitors. They can occur in different parts of the body, particularly the lower legs and feet. One possible explanation is that treatment affects calcium movement in muscle cells, prompting involuntary contractions.

Gentle stretching, massage, walking, warmth or a cold compress may help some people. Staying hydrated, adjusting a sleeping or sitting position, and using a splint at night are other measures to consider. Ask the care team about symptom relief if cramps persist; a clinician can assess whether medication is appropriate.

Severe or ongoing muscle symptoms need prompt discussion with a doctor. The team may order blood tests to look for muscle injury or electrolyte problems. People taking sonidegib may need additional monitoring: blood tests can detect raised creatine kinase, which may signal muscle injury. Severe injury can affect kidney function, so it’s important not to dismiss significant symptoms.

2. Fatigue

About one-third of people using targeted treatment for advanced BCC report fatigue. The medicine may contribute, but other effects can play a part: spasms may disrupt sleep, nausea or taste changes may reduce food intake, and reduced activity can leave someone feeling more tired. The illness itself and emotional strain may also affect energy.

It may help to identify which factors are contributing and bring them to the care team. If activity is suitable, a clinician can help discuss an exercise plan. Some people find it useful to schedule demanding tasks for their higher-energy periods or try gentle practices such as yoga, massage or tai chi. Counseling may help when low mood or mental exhaustion is part of the picture.

3. Hair loss and changes in hair

The hedgehog pathway also supports normal tissue processes, including the hair-growth cycle. Blocking it can lead to shedding and changes in hair texture or quality. Hair loss from these medicines may be permanent, unlike the regrowth many people experience after chemotherapy. Ask the doctor before trying a hair-growth treatment such as minoxidil or an oral dihydrotestosterone inhibitor.

Gentle hair care may limit added stress on the hair: consider mild shampoo, less frequent washing, and reduced use of heat styling or chemical treatments. A hat, scarf or sunscreen can protect the scalp from sun exposure.

4. Taste changes or loss of taste

Because the hedgehog pathway plays a role in the development of taste-bud cells, treatment can alter how food tastes or reduce the sense of taste. These changes may affect up to half of people taking the medicines, and can make it harder to enjoy food or eat enough.

Trying different flavors and textures, eating smaller portions more often, and choosing cold or room-temperature foods may help. Stronger flavors from lemon, spices, seasonings or marinades may make food more appealing. Brushing the teeth and tongue before meals, using a mouthwash, or trying wooden or plastic utensils are other options. Some people try zinc gluconate lozenges; discuss supplements with a clinician or pharmacist.

There is some evidence that THC, a component of cannabis, may improve food taste, appetite and calorie intake in people with taste disturbances. That doesn’t establish that it is suitable for everyone. Ask a doctor before considering cannabis, particularly because it may not be appropriate alongside a person’s other medicines or health conditions.

5. Nausea and other digestive symptoms

Nausea, diarrhea and vomiting can occur, especially when treatment begins. These symptoms may make it harder to maintain hydration and nutrition. A clinician can assess possible contributing issues and discuss supportive care or medicines for nausea. Ask the care team whether an anti-nausea medicine is appropriate and when to take it.

Medication instructions differ: ask whether vismodegib should be taken with food; sonidegib should be taken on an empty stomach. Sipping liquids gradually, choosing clear or cold drinks, and eating small portions of bland foods may be easier on the stomach. Some people find sour foods helpful. If smells trigger nausea, cooler foods may be more tolerable. Fried, spicy or greasy foods can be harder to manage for some people. Relaxation techniques, such as deep breathing or meditation, may also help.

6. Reduced appetite

Taste changes and digestive effects can dampen appetite. Even when hunger is low, getting enough nutrients and calories can become a concern. Keeping convenient snacks nearby and choosing calorie- and protein-rich foods—such as yogurt, eggs, cheese, nuts or dried fruit—may help. Smaller, frequent meals can feel more manageable than three large ones. If food smells are bothersome, cool or room-temperature options may be easier to eat.

Some medicines can increase appetite, but whether one is appropriate depends on the person. Ask the care team about persistent appetite loss and whether nausea treatment before meals might help.

7. Unintended weight loss

Weight loss may reflect the cancer, treatment effects, or a combination of reduced appetite, taste changes and nausea. Regular checks of weight and nutritional status can help identify problems, particularly for older adults or people at greater risk of malnutrition.

Smaller meals throughout the day, balanced foods with more calories, or nutrition drinks may help maintain intake. A registered dietitian or nutritionist can help plan meals around changing tastes and symptoms. Contact the care team about ongoing weight loss, difficulty eating or drinking, or symptoms that interfere with daily life. Early discussion can help the team weigh symptom relief against the goal of controlling the cancer.