Horton v Evans & Anor

A pharmacist must exercise independent professional judgment when dispensing a prescription. Where the pharmacy’s records show a substantial and unexplained departure from the patient’s established medication history, the pharmacist must query the prescription with the prescriber or patient before dispensing it. A prescription falling within the usual therapeutic range is not necessarily suitable for that patient. A later non-negligent medical prescription will not break the chain of causation where the pharmacist’s breach materially caused the later prescription and the later intervention was foreseeable. Liability depends on the damage for which the defendant should properly bear responsibility.

The claimant sued a doctor and Lloyds Pharmacy Limited after receiving dexamethasone at substantially excessive strength, suffering Cushing’s syndrome and consequential physical and psychiatric illness. The claim against the doctor was settled, and the trial proceeded against Lloyds on breach of duty, causation and remoteness.

The pharmacist had dispensed a prescription for tablets eight times stronger than those previously supplied to the claimant, without querying the change. A later United States doctor issued a repeat prescription after relying on the dispensed medication and information supplied by the claimant. The central issues were whether the pharmacist was negligent, whether the later prescription broke the chain of causation, and whether the resulting illness was too remote.

1. Breach of duty. The pharmacist’s common-law duty required an independent assessment of whether the prescribed drug and dose were apt and safe for the patient. The pharmacy’s procedures required previous medication details to be studied and unexplained changes in strength or dose to be queried. The increase from 0.5 mg to 4 mg, against a history of repeated prescriptions at the lower strength, created at least a possibility of error. The pharmacist should have contacted the prescriber or the claimant before dispensing the prescription. His failure to do so fell below the standard of a reasonably careful and competent pharmacist.
2. The omission to check the dose did not cause the harm, since confirmation that the claimant was to take one tablet daily would probably have led to the prescription being dispensed in the same way. The decisive breach was the failure to query the dramatic increase in strength.
3. Causation. The later doctor was not shown to have been negligent. A doctor asked on a single occasion to provide a repeat prescription may ordinarily rely on the previous physician’s treatment, subject to the particular circumstances and appropriate professional evidence. The later doctor’s intervention was not an independent event. The information on the pharmacy label, together with the fact that the bottle represented approximately four weeks’ supply, materially caused him to prescribe 4 mg tablets.
4. Novus actus interveniens and remoteness. The pharmacist’s breach was not eclipsed by the later prescription, which was not unreasonable and was foreseeable. The pharmacist bore real responsibility for the later doctor’s understanding of the medication. It was also reasonably foreseeable that another doctor might read and rely on the dispensing label to identify the previous prescription.
5. The claimant therefore succeeded on breach of duty, causation and remoteness. Quantum was deferred. The time for Lloyds to appeal was directed to run from notification that quantum had been agreed or, failing agreement, from judgment on quantum.

Not stated in the judgment.