Mercury Drug v. Baking: wrong medicine and employer liability

Facts and context

Dr. Cesar Sy prescribed Diamicron for Sebastian Baking’s elevated blood sugar and another medicine for his triglycerides. At a Mercury Drug branch, an employee misread the Diamicron prescription and sold him Dormicum, a potent sleeping tablet.

Unaware of the substitution, Baking took the tablets. He subsequently fell asleep while driving and collided with another vehicle. Suspecting that the medicine had affected him, he returned to Dr. Sy, who identified the dispensing mistake.

Baking sued the drugstore for damages. The trial court found in his favor, and the Court of Appeals affirmed. Mercury Drug challenged both the finding of negligence and the damages, arguing that Baking’s own driving was the proximate cause of the accident.

Issue

Was dispensing Dormicum instead of Diamicron negligent, did that error cause the accident, and was the drugstore liable for its employee’s conduct?

Ruling and doctrine

The Supreme Court upheld liability. Dispensing the wrong drug was gross negligence: the employee should have verified that the medicine supplied matched the physician’s prescription. Because drug dispensing directly affects life and health, the care required must correspond to the danger involved.

The Court found the error to be the proximate cause of the accident. The sedative’s effects explained why Baking fell asleep; the evidence did not support shifting responsibility to him merely because he had been driving. Proximate cause concerns the connection between the negligent act and the injury in a natural, continuous sequence, without an effective intervening cause breaking that connection.

Articles 2176 and 2180 of the Civil Code supported the drugstore’s responsibility. When an employee’s negligence within assigned work causes injury, the employer must meet the applicable burden of showing diligence in selection and supervision to rebut the presumption against it. Mercury Drug failed to establish that diligence.

The Court reduced moral damages from ₱250,000 to ₱50,000, added ₱25,000 exemplary damages, and deleted attorney’s fees and litigation expenses because the trial court’s reasoning had not supplied their basis. The finding of liability therefore survived, while the recoverable amounts changed.

Practice implications

Parao Law practice guidance

For physicians and hospital teams

• Make the intended drug, strength, dose, and instructions clear. Establish a route for the dispenser to clarify an uncertain prescription before supplying medication.
• When an unexpected effect follows a new prescription, review what the patient actually received and took, including packaging and dispensing records, alongside the clinical differential diagnosis.
• Treat prescribing, dispensing, and administration as distinct steps when reviewing an incident. Identify the error and the responsible role at each step.

For lawyers

• Preserve the prescription, supplied product, receipts, dosing history, clinician’s explanation, and evidence of the subsequent event.
• Connect the wrong drug and its effects to the injury; an error and an accident occurring close together still require a supported causal explanation.
• Examine the employer’s actual selection and supervision evidence, as well as the factual and legal basis for each category of damages.

Limits of the ruling

This was a civil case about a drugstore’s dispensing error. The Court did not find Dr. Sy negligent or make every physician responsible for a pharmacy’s mistake. Its causal and employer-liability findings depended on the facts and evidence of this incident.