I missed a dose — what should I do?

Almost everyone on long-term medication misses a dose eventually — a late night, a changed routine, a trip where the bottle stayed on the kitchen bench. A single missed dose is not usually a crisis. What matters is how you respond, and whether it becomes a pattern.

The general principle

For most daily medicines, the usual advice is to take the missed dose when you remember, unless it is nearly time for the next one — in which case you skip it and carry on as normal. Doubling up to "catch up" is generally not recommended.

That said, the specifics genuinely differ between medicines. The instructions that came with yours, and your pharmacist, are the authority here — not a general article. If you are unsure, a pharmacist can usually answer this in a two-minute phone call.

Why consistency matters more than perfection

Hepatitis B antivirals work by keeping the virus suppressed continuously. Their effect depends on maintaining a steady level in your body, which is why the timing tends to matter more than with medicines you take for symptom relief.

Occasional gaps are not the same as stopping. But repeated missed doses can allow the virus to replicate again, and in some cases that contributes to the virus becoming less responsive to the medicine over time. This is the real reason clinicians ask about adherence — not to be disapproving, but because it changes what your results mean.

Be honest with your doctor

If you have missed a lot of doses, say so. It is common, it is not a moral failing, and your doctor cannot interpret a rising viral load correctly without knowing about it. A pattern of missed doses and a genuine loss of response to treatment look similar on paper and are managed completely differently.

Making the next one less likely

• Anchor the dose to something you already do without thinking — brushing your teeth, making coffee, locking the front door.
• Keep a small backup supply somewhere other than home, such as a work bag, if your medicine's storage instructions allow it.
• Set a reminder that repeats, and give yourself a second prompt later in the evening as a safety net.
• Refill early rather than on the last day. Running out is one of the most common causes of a multi-day gap, and it is entirely preventable.
• Plan around travel in advance, including time-zone changes and enough supply for delays.

When to call someone

Contact your doctor or pharmacist if you have missed several days in a row, if you have run out and cannot get a refill quickly, or if you are unsure what to do and cannot find clear instructions for your specific medicine. Do not simply stop and wait until your next appointment.

Further reading

• World Health Organization — Hepatitis B fact sheet
• Hepatitis B Foundation
• ASHM — Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine