I Missed a Dose of My Targeted Therapy: — What Should I Do?

If you are genuinely unsure, do not take another dose. The risk of accidentally doubling is greater than the risk of missing one dose. Continue at your next scheduled time as normal. To prevent this uncertainty in future, a weekly pill organiser or a phone alarm set to the same time each day makes it easy to see at a glance whether you have taken that day's dose.

An occasional missed dose is unlikely to change your outcomes significantly. What matters more is your pattern over time. Regularly missing doses can reduce the drug's ability to control the cancer, because targeted therapies work by maintaining a steady level in your body. Your team needs to know if you are struggling to take doses consistently — they have options to help, and they cannot offer them if they do not know.

The principle is the same, but with twice-daily dosing the gap to your next dose is shorter. This means that when you realise you have missed a dose, you are more likely to be close to the next scheduled time, which makes skipping it the more frequent right answer. Check your patient information card for the specific rule for your drug. The most important rule stays the same regardless: never take two doses at once.

No. Taking two doses together is not how targeted therapy works and does not help the treatment catch up. It raises the drug level in your body sharply, which increases side-effect risk without improving cancer control. If there is still a reasonable gap before your next dose is due, take the missed dose now. If the next dose is nearly due, skip the missed one. Never combine the two.

Call your oncology team before your next appointment rather than waiting. Do not try to take the missed doses or increase your current dose to compensate. Your team needs to know how many doses were missed and why, because this changes how they interpret your next scan results and whether any side effects are connected to underdosing. There is no judgment in this conversation — your team's job is to help you stay on treatment, and they cannot do that without the full picture.

Consistency matters more than the specific clock time. Taking your dose at roughly the same time each day keeps the drug level in your body steady. If the prescribed time does not fit your routine — for example, it clashes with meals when your drug must be taken with food, or you keep forgetting because of your schedule — tell your team. They can often adjust the timing to something you can stick to reliably, and that consistency is what the treatment depends on.

Wait until you can eat something before taking it — even a light snack may be enough, depending on your drug. Check your patient information card for what counts as sufficient food for your specific medicine. Then apply the usual timing rule: if there is still a gap before your next dose, take it with food now; if the next dose is nearly due, skip it. If poor appetite is regularly making it hard to take your doses correctly, tell your team — this is something they can help with.

Yes, especially if it is happening more than occasionally or you missed several doses in a row. Your oncologist uses your dose history to interpret your response to treatment and any side effects you are experiencing. If you have been missing doses without their knowledge, they may draw the wrong conclusions from your results. Mentioning a missed dose is not a problem — it is information they need. If you are missing doses because of side effects, cost, or difficulty swallowing tablets, say so directly: all of those are things your team can act on.