Headaches and Dizziness on Targeted Therapy — What Is Safe at Home and What Is Not

Not without asking your oncology team first. Several targeted therapies interact with anti-inflammatory medicines, and ibuprofen can also put extra pressure on kidneys that may already be affected by the drug. Paracetamol is the safer starting point for most people on targeted therapy, but your team can confirm what applies to your specific agent. If you have taken ibuprofen occasionally in the past and it has not been flagged, that conversation is still worth having at your next appointment.

Different targeted agents cause headaches for different reasons. Those that block blood vessel growth signals often raise blood pressure, and raised blood pressure can cause headaches directly. Others have effects on the nervous system as part of how they work. Some headaches are also linked to dehydration or disrupted sleep caused by other side effects. Your oncologist can tell you which mechanism is most likely for your specific drug — that also tells you what the right response is, since the fix for a blood pressure headache is different from the fix for a dehydration headache.

For many people, yes. Mild drug-related headaches often improve after the first few weeks as the body adjusts to treatment. But this does not apply to everyone, and it depends on the specific agent and whether blood pressure is part of the cause. If blood pressure is driving the headaches, they will not settle until the blood pressure is managed — which may mean adding a blood pressure medicine. Tell your team if headaches are an ongoing problem rather than assuming they will improve on their own.

Dizziness that is a drug side effect tends to be mild, gradual in onset, and often settles when you sit or lie down. The features that make it more urgent are sudden onset, dizziness that does not settle with rest, dizziness with vomiting or difficulty walking steadily, or any weakness or speech change alongside it. Dizziness when you stand up quickly is often a brief blood pressure drop — standing slowly usually helps — but if it is happening repeatedly or is severe, tell your team rather than continuing to manage it alone.

Your team will give you a specific range, because the target varies by person and by the drug you are taking. Write your readings down with the date and time and bring the record to every appointment. The reason to call between appointments is any reading that is consistently higher than what your team told you to expect, or a single very high reading — especially if it comes alongside a headache or you feel unwell. If you are unsure whether a reading is too high, call and read the number to your team rather than trying to judge it yourself.