Gefitinib in Elderly Patients — and Those With Other Illnesses

No. Age alone does not change the dose of gefitinib. Clinical guidance from NCCN and ESMO does not recommend routine dose adjustment based on how old you are. The dose may change only if a specific issue — such as significant liver impairment or a serious drug interaction — makes a different approach necessary. If you are wondering whether your particular health conditions affect your dose, that is a direct question for your oncologist, and the answer will be based on your organ function and medicines, not your age.

In most cases, yes. Gefitinib is broken down almost entirely by the liver, and very little of it is excreted through the kidneys unchanged. Mild-to-moderate kidney disease does not usually require any change in how you take the drug. If your kidney function is severely reduced, evidence in that group is more limited and your team will monitor you more closely. Tell your oncologist your most recent kidney function results so they can review this alongside your full picture.

Liver disease is more relevant to gefitinib than kidney disease because the drug is metabolised mainly in the liver. If your liver is not working as well as usual, gefitinib may stay in your body longer than intended, which can increase side effects. Your oncologist will check your liver function tests before starting treatment and repeat them at intervals during treatment. If your liver impairment is significant, they will discuss whether gefitinib remains the right option and what monitoring is needed.

COPD and gefitinib can coexist, but the more specific concern is lung scarring or fibrosis rather than airflow limitation. Gefitinib can cause a rare but serious inflammatory reaction in the lung tissue in a proportion of patients. If you already have lung fibrosis or a history of lung inflammation, this risk is higher. Tell your oncologist your full lung history, including any previous CT scans that showed changes in your lung tissue. They will weigh this against the expected benefit before making a decision.

It can be, depending on which medicines. Some commonly used drugs interact with gefitinib in ways that matter clinically. Medicines that induce liver enzymes — including certain antiepileptics and rifampicin used for tuberculosis — can lower gefitinib levels in the blood and reduce how well it works. Blood thinners such as warfarin can have their effect increased by gefitinib. This is why a full medicines review before starting is not optional. Include over-the-counter medicines and anything you take without a prescription.

Yes, and it is worth raising with your oncologist before you start. Gefitinib dissolves and is absorbed better in an acidic stomach environment. Medicines that reduce stomach acid — proton pump inhibitors such as omeprazole, pantoprazole, and rabeprazole — can significantly reduce how much gefitinib your body absorbs. This is a documented interaction noted in prescribing guidance. Your oncologist may advise a timing change, an alternative acid-reducing medicine, or review whether the PPI is still necessary during treatment.

Tell your oncologist about any heart condition, and list all your cardiac medicines, before starting. Gefitinib can prolong the QT interval — a measurement on an ECG that reflects the heart's electrical cycle — in a proportion of patients. If you already have a prolonged QT interval, or if you take other medicines known to affect heart rhythm, your team may arrange a baseline ECG and periodic monitoring during treatment. This does not mean you cannot take gefitinib, but it is information your team needs to plan your monitoring.

Not necessarily more severe, but some side effects carry more consequences in older patients. Diarrhoea, which is common with gefitinib, can lead to dehydration more quickly in elderly patients, and dehydration in turn can affect kidney function and other medicines you take. Skin rash may take longer to heal. This is why monitoring is often closer for older patients rather than the dose being lower. If you develop loose motions or a significant skin reaction, contact your team earlier rather than waiting until your next scheduled appointment.