Missed a dose of pertuzumab? What to do

Pertuzumab is given in a hospital or day care unit, usually every three weeks, so a missed dose normally means a delayed visit rather than a forgotten tablet. Delays happen for many reasons: illness, a fever, low blood counts during chemotherapy, a heart scan result that needs checking, travel, festivals or simply a scheduling problem. The most important step is to tell your treatment team as soon as you know you will miss a visit, and to rebook as soon as you are able. Do not wait for the next planned date. What your team does next depends on how long it has been since your last dose. If the gap is shorter than about six weeks, the usual approach is simply to give your regular dose as soon as possible and then return to a three-weekly schedule from that date. If the gap is six weeks or longer, the medicine level in your blood may have fallen too far, so a larger reloading dose, like the very first dose, is usually given, followed by regular doses every three weeks. The same principle applies to trastuzumab given alongside, and to the combined injection under the skin, although the exact rules differ slightly. A single short delay is unlikely to make a meaningful difference to how well treatment works. Repeated or long gaps are more of a concern, so let your team know early if something is making visits difficult.

Tell your team quickly

Early contact lets your team rebook you and plan the right dose.

The gap decides the dose

A shorter gap means your usual dose. A longer gap usually means a reloading dose.

Short delays rarely matter

One brief delay is unlikely to reduce the benefit of treatment.

Dosing rules for delays are based on how the medicine behaves in the body, not on trials comparing people who missed doses with those who did not.

No exact measure of harm

No one can say precisely how a delay affects your own outcome. Doctors rely on medicine levels and clinical experience.

Delays for safety are right

Postponing treatment for infection, low counts or heart changes protects you and is part of good care.

Repeated gaps matter more

Frequent or long interruptions are more likely to reduce benefit than one short delay.

What this page cannot tell you

It cannot decide your dose after a gap. Only your treatment team can review your records and plan the next dose.

Being unwell is one of the most common reasons for a delay, and it deserves proper attention.

Fever and infection

A temperature of thirty-eight degrees or above during chemotherapy needs urgent assessment. The next dose is usually given once the infection is treated.

Severe diarrhoea

Treatment may be postponed until loose motions settle and fluids are replaced.

Breathlessness or swelling

These can be heart warning signs, so a scan may be needed before your next dose.