Using over-the-counter medicines safely

Medicines you can buy without a prescription are safe when used as directed, but most accidental overdoses happen because people take two products that contain the same ingredient. This lesson teaches you to read a label like a pharmacist.

Read the label every time

• Look for the active ingredient (for example paracetamol or ibuprofen), not the brand name; the same ingredient is sold under many names.
• Check the strength (for example 500mg or 200mg per tablet), how many to take, the minimum gap between doses and the maximum in 24 hours.
• Read the 'do not take if' section: the NHS lists groups who should check with a pharmacist first for each medicine.
• If anything is unclear, ask the pharmacist: 'I already take X. Is it safe to take this too?' This is free and is exactly their job.

Paracetamol: the NHS basics for adults

• The NHS adult guidance for 500mg tablets is 1 or 2 tablets per dose, with at least 4 hours between doses and no more than 8 tablets in 24 hours.
• If you weigh under 50kg, the NHS says you may need a lower dose, so check with a pharmacist.
• Do not take paracetamol for more than 3 days unless a doctor tells you to.
• Avoid taking it with other paracetamol-containing medicines, such as many cold and flu remedies, because you may take too much, which can be dangerous.
• If you have taken more than the packet says, the NHS advises getting medical advice (NHS 111 in the UK) even if you feel fine, because too much can damage the liver.

Ibuprofen: the NHS basics for adults

• For 200mg tablets, the NHS adult guidance is 1 or 2 tablets up to 3 times a day, at least 4 hours apart, with no more than 6 tablets in 24 hours.
• Take it ideally with or after food, swallowed whole with water.
• Check with a pharmacist first if you have asthma, a stomach ulcer now or in the past, or heart, liver or kidney problems.
• Do not take it at the same time as other anti-inflammatory painkillers (NSAIDs) such as naproxen or aspirin, because this raises the risk of serious side effects like stomach ulcers.
• Do not take ibuprofen tablets for more than 10 days unless a doctor advises it.

Never double up on the same ingredient

• Worked example: you take 2 paracetamol tablets at 8am for a headache, then at 10am a 'cold and flu' sachet. If that sachet also contains paracetamol, you have taken a second dose only 2 hours later.
• The NHS flu page warns that if paracetamol is in both your tablets and a flu remedy, it is easy to take more than the recommended dose.
• The NHS cold page says not to use other cough and cold medicines if you are also taking paracetamol and ibuprofen tablets.
• The NHS says adults can take paracetamol and ibuprofen together if needed, because they are different ingredients, but suggests trying each on its own first and using the lowest dose that works.
• Keep a simple log on your phone: time, medicine, dose. When you are feverish it is easy to forget when you last took something.

Other safe-use habits

• Never share prescription medicines or take someone else's; antibiotics, for example, do not work on colds or flu, which are viruses (NHS).
• Nasal decongestant sprays should not be used for more than a week, as the NHS says this can make symptoms worse.
• If you are 15 or under, the dosing on adult packs may not apply to you; ask a pharmacist. The NHS says aspirin should not be given to anyone under 16.
• Medicine rules differ between countries; some medicines sold freely in one country need a prescription in another, so see the Getting Around module's lesson on medicines when travelling.