Most household medicines do not need a fridge and never did. What they need is somewhere cool, dark and dry, which is precisely what a bathroom cabinet is not.
A small number genuinely require cold, and one of those, insulin, is a life-or-death planning problem for any household that depends on it.
What actually degrades medicine
Four things, in roughly this order of importance:
Heat. The dominant factor. Chemical degradation roughly doubles for every 10°C rise, so a medicine in a loft, a car, or a sunny windowsill ages far faster than the date on the box assumes.
Moisture. Tablets and capsules are hygroscopic. Damp causes them to break down, clump and lose potency. This is why the bathroom is the worst place in the house for medicines, despite being where almost everyone keeps them: steam, temperature swings and humidity, daily.
Light. Degrades many drugs, which is why so many come in amber bottles or foil blisters. Keep things in their original packaging.
Air and handling. Decanting tablets into a pill organiser weeks in advance exposes them, and removes the label, the batch and the expiry date.
Insulin, the hard case
The important and useful fact: an in-use vial or pen does not need refrigeration at all. It is designed to sit at room temperature for 28 days. Many people refrigerate in-use insulin unnecessarily, and injecting cold insulin is more painful.
So the problem is not the vial in use. It is the stock, which needs 2 to 8°C to last to its expiry date.
Planning consequences for a household that depends on insulin, and these are worth acting on now rather than later:
- Know how much you actually have and what its expiry dates are.
- Talk to the GP or pharmacist in advance about holding a reasonable buffer. This is a legitimate conversation and easier to have calmly.
- Have a cooling plan that does not need power, below.
- Never let it freeze, which in Britain is the likelier failure.
- Know that in a real emergency an expired or imperfectly stored insulin is better than none, and that this is a judgement to make with a clinician if one is reachable, not a licence to be careless.
The same logic applies to any refrigerated medicine: some antibiotics in liquid form, some eye drops, adrenaline auto-injectors (which need room temperature, not cold, and must not freeze), and certain injectables.
Keeping things cool with no power
The evaporative cooler, or zeer pot, is the technique that works with no electricity at all.
- Take two unglazed terracotta pots, one fitting inside the other with a gap of 2 to 3 cm.
- Block the drainage hole of the outer pot.
- Fill the gap with clean sand.
- Saturate the sand with water.
- Put the medicine, sealed in a bag or box, in the inner pot.
- Cover the top with a wet cloth.
- Keep the sand damp, topping up once or twice a day.
- Site it in shade with moving air. Airflow drives evaporation, which is what does the cooling.
It works by evaporation, so it performs best in dry moving air and worst in humid still air. In a British summer expect a useful drop below ambient rather than fridge temperature, and understand that it will not reliably hit 2 to 8°C. It is a way of keeping things cool, not cold.
Other approaches:
- A cellar or under-floor space, which is naturally cool and stable.
- A north-facing room, at floor level.
- A container buried in the ground, below the frost line, which is remarkably stable year-round.
- A stream or spring, with the medicine sealed watertight.
- A cool box with rotated ice packs, if there is any intermittent power.
Expiry dates, honestly
This deserves a straight answer rather than either extreme.
What an expiry date means: the manufacturer guarantees full potency and safety to that date, stored correctly. It is not the moment the drug becomes dangerous.
What is generally true: most solid dose forms, tablets and capsules stored cool and dry, retain most of their potency well beyond the printed date. Studies of stockpiled medicines have found many remain substantially potent years past expiry.
The medicines worth stocking
Not a prescription, just the categories a household repeatedly wishes it had.
- Paracetamol and ibuprofen, adult and children's liquid forms. The single most useful pair.
- Oral rehydration salts. See oral rehydration. Cheap, tiny, long shelf life, disproportionately valuable.
- Antihistamines, non-drowsy and drowsy.
- Antiseptic for skin, not for wounds. See wound care.
- Dressings: non-adherent pads, gauze, tape, crepe bandage, triangular bandage, blister plasters.
- Cling film, for burns.
- Tweezers, scissors, tick removal tool, thermometer.
- Anything anyone in the household takes regularly, with as much buffer as your GP will support.
- Rehydration for pets and any animal medicines.
- Temporary dental filling material, clove oil, dental wax. See dental first aid.
Rotation and records
- Write the opening date on anything with a post-opening life, especially insulin, eye drops and liquid antibiotics.
- Check the whole cupboard twice a year, at the clock changes, which is an easy trigger to remember.
- Use the oldest first, and buy replacements before the last one is gone rather than after.
- Keep a written list of what everyone takes, doses, and allergies. Put a copy in the document pack and one in the go-bag.
- Dispose of old medicine at a pharmacy, not down the toilet or in the bin, while pharmacies exist.