Sunitinib Side Effects: — Timeline and When to Call

Sunitinib blocks the growth of small blood vessels throughout the body, and the skin on your palms and soles is under constant pressure and friction — making it the place this effect shows first. You may notice redness, tenderness, peeling, or blisters. Thick moisturising cream applied twice daily, starting before cycle one begins, is the evidence-supported way to reduce severity. Avoid tight footwear, vigorous walking on rough surfaces, and prolonged hot water on affected skin. If your skin cracks or blisters form, tell your team before your next scheduled visit, not at it.

Sunitinib raises blood pressure by reducing the number of functioning small blood vessels, which increases the pressure on those that remain. This is very common and manageable, but it can reach levels that risk a stroke or heart event if it goes unnoticed. A home blood pressure monitor used daily is the single most useful thing you can own during sunitinib treatment. Your team will usually start a blood pressure medicine or adjust one you already take. Do not stop or adjust either without telling them first.

Fatigue on sunitinib has several causes that can overlap — the drug itself, lower red blood cell counts, and sometimes hypothyroidism that develops silently over weeks. A gradual increase in tiredness across cycles is different from a sudden sharp drop in energy, which is worth reporting sooner rather than waiting for the next appointment. Light regular activity, a consistent sleep routine, and eating small meals through the day help at the mild end. If you feel too tired to manage basic daily tasks for more than a few days in a row, tell your team.

Sunitinib itself has a yellow pigment, and this can give your skin a yellow tinge and lighten or yellow the colour of your hair during treatment. This is a direct cosmetic effect of the drug compound and is not a sign of liver damage. It is different from jaundice, which results from bile pigment accumulating when the liver is stressed and usually appears in the whites of the eyes first. If yellowing appears in your eyes, or comes with dark urine or abdominal pain, contact your team the same day. Skin tinting alone, without those signs, needs a mention at your next appointment but is not urgent.

Sunitinib can cause the thyroid gland to produce less hormone over months of treatment, leading to tiredness, feeling cold all the time, weight gain, constipation, and low mood. These symptoms develop so gradually that they are often attributed to the cancer or to general treatment fatigue rather than to a treatable hormonal change. Your team will monitor thyroid function through regular blood tests. If thyroid levels fall below normal, a daily tablet usually corrects it. Report these symptoms between scheduled tests rather than waiting, if they are noticeably affecting you.

Blood counts typically fall to their lowest point — the nadir — around weeks three and four of each four-week cycle, then recover during the one-week rest before the next cycle begins. Low white cell counts increase your risk of infection; low platelet counts increase bleeding risk. You cannot feel your blood count dropping, which is exactly why the scheduled blood tests exist. A fever, unusual bruising, bleeding gums, or feeling suddenly very unwell during this window is a signal to call your team the same day rather than waiting for your next visit.