What is a medication error?
Short answer
A medication error is any preventable event that may cause inappropriate medication use or patient harm. In medical negligence, an actionable error is one that fell below the standard a reasonably competent clinician or pharmacist would have applied and that caused harm to the patient.
Medication errors can occur at any stage: prescribing, dispensing, and administration are all potential points of failure — and all can give rise to claims.
Who can be responsible for a medication error?
Prescribing errors — the clinician
A prescribing error is made by the clinician who writes or authorises the prescription — GP, hospital doctor, specialist, or nurse prescriber. Errors include wrong drug, wrong dose, wrong frequency, wrong route, failure to check contraindications, failure to check for drug interactions, and failure to review the patient's current medication list.
Dispensing errors — the pharmacist
A dispensing error occurs when a pharmacist or pharmacy technician dispenses a different drug or dose from the one prescribed. This can occur in community pharmacies, hospital pharmacies, and online pharmacies.
Administration errors — nursing and clinical staff
Administration errors occur when the medication reaches the patient incorrectly — wrong patient, wrong time, wrong dose, wrong route. These are common on hospital wards and in care homes. Nursing staff and healthcare assistants who administer medications have a duty to check the prescription and the patient identity before administering.
What are the most common types of medication error in negligence claims?
Prescribing the wrong drug
A drug prescribed when a different drug was intended — for example, prescribing the wrong antibiotic for a known allergy, or prescribing a drug with a similar name to the intended drug (a "look-alike, sound-alike" error).
Wrong dose
A dose prescribed, dispensed, or administered that is outside the safe or therapeutic range for that patient — either too high (causing toxicity) or too low (causing ineffective treatment that allows the condition to worsen). Common in paediatric dosing errors and in patients with renal or hepatic impairment.
Failure to check for allergies
A GP or hospital doctor who prescribes a drug to which the patient is known to be allergic — where the allergy was recorded in the notes — is likely to have been negligent. Allergy checking is a basic prescribing duty.
Dangerous drug interactions
Prescribing a drug that interacts dangerously with medication the patient is already taking — where the interaction was known and documented and should have been identified before prescribing.
Failure to monitor
Some medications require ongoing monitoring — lithium levels, INR monitoring for warfarin, renal function monitoring for methotrexate. Failure to arrange monitoring, or failure to act on out-of-range results, can cause serious harm.
Failure to review existing medication on hospital admission
When a patient is admitted to hospital, a medication reconciliation review should ensure all their regular medications are continued or appropriately changed. Failure to review medications on admission — or failure to restart medications after discharge — is a common source of medication errors.
Dispensing errors in community pharmacy
Dispensing the wrong drug (a different product from the one prescribed), the wrong strength, or providing medications intended for a different patient can cause serious harm. These errors are less common than prescribing errors but do occur.
What do you need to prove?
- Duty of care — the prescriber, pharmacist, or administering clinician owed you a duty to handle your medication correctly.
- Breach of duty — the error fell below the standard of a reasonably competent prescriber, pharmacist, or administering clinician. An independent expert in the relevant specialty will assess this.
- Causation — the error caused your harm. In medication error cases, causation often involves medical evidence about the effect of the wrong drug or dose on the patient's condition.
- Damage — physical, psychological, or financial harm resulted.
Evidence for a medication error claim
| Evidence | What it shows |
|---|---|
| Prescription records | What was prescribed and by whom |
| Dispensing records | What was dispensed by the pharmacy |
| Medication administration records (MAR charts) | What was administered in hospital or care home |
| Medical records showing allergy status | Whether the allergy was recorded and should have been checked |
| Records of monitoring (or lack of it) | Whether required monitoring was carried out |
| Records of the resulting harm | Clinical records showing the effect of the medication error |
| Independent expert report | Whether the prescribing, dispensing, or administration met the required standard |
What is the time limit?
Three years from the date of the error, or from the date of knowledge — when you knew or ought reasonably to have known that a medication error caused your harm. Children have until age 21. Fatal cases: three years from date of death or date of knowledge.
How is a medication error claim funded?
Most medication error claims are funded on a Conditional Fee Agreement — no win no fee. You pay nothing upfront and nothing if the claim fails. Success fees are capped at 25% of past losses and general damages; future losses are fully protected.
Frequently asked questions
Can I claim against both the GP who prescribed and the pharmacist who dispensed?
Yes, if both fell below the required standard. Your solicitor will identify the appropriate defendants based on where the error occurred.
What if I didn't read the label or notice the wrong medication?
A patient's responsibility to check their own medication is limited. The duty to prescribe and dispense correctly rests primarily with the clinician and pharmacist. However, contributory negligence may be argued where the patient ignored clear warnings.
Can I claim if a hospital gave me the wrong medication on a ward?
Yes. Hospital administration errors are subject to the same negligence framework. Nurses and healthcare assistants who administer medications have a duty to check the prescription and verify the patient's identity.
Can I claim if my child was given the wrong dose of medication?
Yes. Paediatric dosing errors are a serious concern and are assessed by reference to the standard of a reasonably competent clinician prescribing for paediatric patients.
Related guides
- Medical negligence claims — complete guide
- GP negligence claims
- Hospital negligence claims
- How to prove medical negligence
- Time limits for medical negligence claims
- The claims process explained
Sources & further reading
Primary statute, case law and regulator guidance referenced in this article.
- Bolam v Friern Hospital Management Committee [1957] 1 WLR 582 — Case law
- Bolitho v City and Hackney Health Authority [1997] UKHL 46 — Case law
- British National Formulary (BNF) — NICE / BNF
- General Pharmaceutical Council — standards for pharmacy professionals — GPhC
- NICE NG5 — Medicines optimisation — NICE
- Limitation Act 1980 — UK Legislation