Maximum daily doses: the numbers that matter
Paracetamol overdose is the leading cause of acute liver failure in the UK and US. Most cases are accidental. The patient takes 1g four times a day, also takes two co-codamol for back pain, and a cold and flu remedy at night. By 11pm they've had 5g. They had no idea.
The paracetamol problem
Healthy adult maximum: 4g per day. Elderly, liver disease or regular heavy alcohol: 2g per day. The critical thing: check every product you take for paracetamol content. Co-codamol, Lemsip, Night Nurse, Sudafed, Tylenol Cold, Percocet. It's everywhere. Our Drug Interaction Checker can flag paracetamol combinations across your regimen.
NSAIDs: the OTC overuse problem
Ibuprofen OTC maximum: 1200mg/day. Prescription maximum: 2400mg/day. But most people don't know there's a difference. A patient on 400mg four times daily has already hit the OTC max. Add in a prescription NSAID or a topical gel and they're over. NSAIDs also accumulate risk in a renal-dose-dependent way. If you have kidney disease, see the Renal Dose Adjustment Calculator before using any NSAID.
Elderly patients: lower limits across the board
Renal function declines with age even when serum creatinine looks normal. Liver enzyme activity falls. Body composition changes. The practical result: standard adult maximum doses are often too high for a 75-year-old. This tool applies lower limits for elderly patients automatically when you select that profile.
Combination products: where most accidental overdoses happen
Cold and flu medications, pain combinations, and OTC sleep aids frequently contain multiple active ingredients at borderline doses. Before taking any combination product, check the ingredient list against everything else you're already taking. The maximum dose for any individual ingredient doesn't change just because it's in a combination product.