Every time you move between settings — a new clinic, a hospital admission, a discharge — someone has to reconcile what you are actually taking against what the record says. That process, medication reconciliation, is one of the most common places errors enter care: a drug continued that should have stopped, a duplicate under two names, an interaction nobody spotted because the herbal supplement was never mentioned. The single most useful thing a patient can bring is an accurate, complete, current list.
What belongs on it
Everything. Prescriptions, obviously. But also over-the-counter painkillers, antacids, antihistamines and sleep aids; vitamins and minerals; protein powders and herbal products; eye drops, inhalers, patches, creams and injections. People routinely omit these because they do not feel like medicines, yet several matter clinically: St John’s wort reduces the effect of many drugs including some contraceptives and anticoagulants; high-dose vitamin K interacts with warfarin; NSAIDs raise blood pressure and stress the kidneys; grapefruit changes the metabolism of several statins.
How to keep it true
Update it at the moment something changes, not later. Bring it to every appointment and ask the clinician to check it against their record — the gaps that turn up are the point of the exercise. Once a year, book a pharmacist review: they are the professionals most likely to spot a duplicate, an unnecessary continuation, or an interaction, and in many places the review is free.
What to do about allergies
Keep drug allergies and past reactions with the list, and record what actually happened — a rash, breathing difficulty, or an upset stomach are very different pieces of information, and “allergic to penicillin” recorded for childhood nausea can close off good options for decades.