If you miss a dose

There is a rule, and it is specific to your medicine

Every one of these medicines has a defined rule for a missed dose, and the rules are not the same. They differ in how long after the missed dose you may still take it, and in what to do once that window has passed. The numbers are different between a weekly injection and a daily tablet, and they are different between one weekly injection and another.

That is why this page does not give you a number. A number that is right for one medicine and wrong for yours is worse than no number at all.

The rule that applies to you is in the patient information leaflet supplied with your medicine, under a heading about a forgotten or missed dose. The same leaflet is published on the electronic medicines compendium. Read the one for the medicine and the strength you actually have.

The rules that are the same for everything

Three things hold whatever you are taking.

Never take a double dose to make up for a missed one. Not two injections, not two tablets, not a larger amount from a pen. Doubling up is how a manageable miss becomes a reason to call 111.

Do not change your regular day or your regular timing on your own. For a weekly injection, if you need to move the day you take it, there is usually a minimum gap that must be left between doses first. That gap is in the leaflet, and if it is not clear, ask us before you move it.

If you are not sure, ask before you act. We answer questions about a medicine we have supplied during opening hours; message us from your account so it reaches a clinician with your record. Out of hours, 111 is open and can advise. A missed dose is not an emergency, but guessing at the correction can create one.

A single missed dose

One missed dose is common and, for most people, not a crisis. Follow the leaflet’s rule. Then tell us at your next check-in — missed doses are one of the things the check-in asks about, and not because anybody is keeping score. Whether a strength was actually taken as prescribed changes how a prescriber reads everything else: how well it was tolerated, how your weight has moved, and whether an increase is appropriate.

An answer of “I missed two” is more useful than an answer of “fine”.

Missing doses repeatedly

If you are missing doses regularly, something is usually behind it — side effects that make you dread the next one, a routine that does not fit the schedule, a pen that ran out, cost, or simply forgetting. All of those are worth saying out loud, because most of them have a response.

What is not a good response is quietly carrying on at a strength you are not actually taking. A prescriber assessing an increase is assessing how a strength went, and if it did not really happen then the assessment is being made on something that is not true.

A longer gap, and what a restart means

Tolerance to these medicines builds with regular exposure and it fades without it. After a long enough break, going straight back to the strength you stopped at risks the side effects that the original slow climb existed to avoid.

So after a significant gap, treatment is restarted rather than resumed: usually from a lower strength, working back up through the ladder. How far back, and how quickly, is a clinical judgement your prescriber makes based on how long you were away and what you were on. It is not a penalty, and it is not something to be talked out of.

Our reminders exist partly to stop that happening. You are told before your supply runs out rather than after, and if the date passes you are told what a longer gap would mean. If you know a break is coming, tell us in advance — there is more that can be done before a gap than after one.

If missing a dose was because you were unwell

If you stopped because the medicine was making you ill, that is a report rather than a lapse. Tell us what happened so a prescriber can decide whether to reduce the strength, pause, or stop. Anything you suspect the medicine caused should also be reported — to us and to the MHRA, and you do not need to be certain. If you are unwell now, urgent help and out of hours says who to contact.