Max daily dose checker

Free

Check whether a planned medication dose and frequency is within the published maximum safe daily limit. Enter the drug name, your single dose and how many times per day you take it. Covers adult, elderly and reduced-limit populations.

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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. The FDA's acetaminophen safety page confirms this combination-product risk is a leading cause of overdose.

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, and separately from that, the FDA's strengthened NSAID warning notes the heart attack and stroke risk applies at any dose and can appear within the first weeks of use. 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. If you want the actual estimated renal function behind that adjustment, our Creatinine Clearance Calculator shows the number itself rather than just the age-based assumption.

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, our Drug Interaction Checker can flag overlapping active ingredients like paracetamol across a whole regimen. The maximum dose for any individual ingredient doesn't change just because it's in a combination product.

Frequently asked questions

For healthy adults: 4g (4000mg) per 24 hours, with individual doses no more than 1g and at least 4 hours between doses. For elderly patients, those with liver disease or chronic heavy alcohol users: 2g per day maximum. Many combination products contain paracetamol - always account for all sources when calculating daily intake.
OTC (self-medication) maximum: 1200mg per day. Under medical supervision: up to 2400mg per day. For elderly patients: 1200mg per day maximum. Always take with food and avoid in kidney disease, active peptic ulcer or heart failure.
Renal function declines with age even when serum creatinine appears normal, slowing drug elimination. Liver enzyme activity also decreases. Body composition changes reduce the volume of distribution. The practical result is that standard adult doses accumulate to higher blood levels in elderly patients, increasing toxicity risk.
It depends on the drug. Exceeding the paracetamol maximum causes liver failure (which may not be apparent for 24-72 hours after ingestion). Exceeding NSAID limits causes GI bleeding, kidney injury and cardiovascular events. Exceeding benzodiazepine limits causes respiratory depression. If you think you or someone else has exceeded a maximum dose, contact poison control or emergency services immediately.