Hello, this is attorney Oh Seung-hyun of Cheongchul Law Firm.

"The chart said I was allergic to cephalosporin-class antibiotics." Yet the medical staff administered an antibiotic of the same class, and anaphylactic shock followed. Even the emergency response was mishandled, and a 37-year-old nurse died of hypoxic brain injury. Or cases like this: "They gave my mother an anticancer drug meant for another patient." Medication errors account for the largest share of preventable medical accidents. And the courts say it plainly — if the allergy check was neglected, if the dose was exceeded, if another patient's drug was administered, or if something other than epinephrine was used for anaphylactic shock, that is malpractice.

Five Types of Medication Error

(1) Failure to Check Allergy History — Taking a History Before Prescribing Is a Basic Duty

Prescribing without checking a history of drug allergies or adverse reactions is the most typical medication error. The Cheongju District Court found malpractice in a case where a physician prescribed an injectable containing diclofenac to a patient with an ankle injury without taking any history of past illness or medication, leading to death from anaphylactic shock (Cheongju District Court 2017Gahap202415, August 19, 2019). In another case, failing to specifically explain the risks peculiar to renal failure (a 27% incidence of nephrotoxicity) when performing a contrast-enhanced CT on a patient with severe renal failure was found to be a breach of the duty to explain (Gwangju District Court 2021Gahap63131, July 23, 2024).

(2) Inadequate Emergency Response After Allergic Shock

When an allergic reaction occurs, mishandling the emergency response constitutes a separate act of malpractice. The Busan District Court found compound malpractice where, after an antibiotic was administered to a patient whose chart recorded a cephalosporin allergy and a secondary anaphylactic shock occurred, the medical staff (i) administered ephedrine instead of epinephrine, (ii) performed CPR improperly, and (iii) delayed transfer to another hospital by 35 minutes. A 37-year-old nurse died of hypoxic brain injury, and the court apportioned 30% liability and ordered payment of KRW 133.21 million to each plaintiff (the parents) (Busan District Court 2017Gahap52562, February 19, 2020).

(3) Patients With a History of Severe Contrast-Media Reactions — Duty to Consider Alternative Tests

For patients with a history of severe hypersensitivity to contrast media, premedication alone is not enough. The criminal division of the Seoul Western District Court imposed a fine of KRW 15 million for occupational negligence resulting in death on a physician who, for a 74-year-old patient who had previously experienced fainting and fecal incontinence after contrast media use, ordered a contrast-enhanced CT without performing a skin reaction test and without considering alternative tests such as MRI, leading to death by cardiac arrest (Seoul Western District Court 2023Godan1504, February 5, 2025). The court expressly stated that "it is an established fact in the medical community that premedication alone cannot prevent severe anaphylaxis."

(4) Administering an Anticancer Drug to the Wrong Patient — Breach of the Duty to Verify the Patient

Failing to accurately verify the patient at the time of administration causes accidents in which a drug that was never intended for that patient is given. The Incheon District Court found malpractice and rendered a partial judgment for the plaintiff in a case where the anticancer drug Velcade was mistakenly administered without patient verification, after which leukoencephalopathy caused permanent disabilities including reduced vision and gait disturbance (Incheon District Court 2020Gahap58969, September 10, 2024). By contrast, there is also a case in which the mistaken administration of the anticancer drug Monotaxel to the wrong patient was itself found to be malpractice, but the claim was dismissed because causation with the death could not be proven (Busan District Court 2023Gadan344234, May 21, 2024). A finding of malpractice does not automatically bring compensation — causation between that malpractice and the loss must also be proven.

(5) Delayed Antibiotic Prescription After Signs of Infection Are Found

Failing to prescribe appropriate antibiotics in time or delaying transfer despite clear signs of sepsis after surgery constitutes malpractice. The Ulsan District Court, in a case where clear signs of sepsis such as a white blood cell count of 26,990 were present after hemorrhoid surgery but the prescription of potent antibiotics and transfer were delayed, resulting in death from necrotizing fasciitis and multiple organ failure, ordered payment of KRW 305.43 million to the plaintiff spouse and KRW 201.97 million to each child (Ulsan District Court 2014Gahap17387, May 11, 2017).

When Malpractice Is Denied

(1) No Abnormality on Repeated Administration and a Very Low Incidence Rate

Where the same drug was administered several times without adverse reactions and the incidence of anaphylaxis for that drug is extremely low, malpractice may be denied. The Jeonju District Court denied malpractice on the grounds that there had been no adverse reaction on each of five administrations of Pazidon (a cephalosporin-class antibiotic), that a skin reaction test had also confirmed a negative result, and that the incidence of cephalosporin anaphylaxis is only 0.0001–0.1% (Jeonju District Court 2019Gadan10790, November 17, 2021). Where there is a past record and appropriate advance verification, foreseeability itself becomes low.

(2) Malpractice Is Found but There Is No Causation

Even if the medication error itself is found, no compensation is awarded if the patient's side fails to prove causation between that error and the patient's death or sequelae. The Busan District Court found the mistaken administration of another patient's anticancer drug to be malpractice, yet dismissed the claim on the ground that there was insufficient evidence that the mistaken administration was the cause of the deceased's death (Busan District Court 2023Gadan344234, May 21, 2024). In medication error litigation, a strategy for proving causation must be prepared alongside proof of malpractice.

Key Evidence to Secure in a Medication Accident

(1) Prescriptions and Administration Records — Compare Dose and Drug Name Against the Approved Labeling

The first step is to compare the drug name and dose written on the prescription with the maximum permitted dose in that drug's approved labeling (package insert). Nursing administration records state the actual time of administration, the dose, and the nurse in charge. If the prescription and the actual administration do not match, or if the patient who received the drug was not the intended recipient, this becomes the key evidence of a wrong-patient administration error.

(2) Allergy Registration Records and History-Taking Records

You must check whether the allergy history taken at admission or the first visit is reflected in the electronic medical record (EMR). If the patient disclosed an allergy but it was not registered in the prescribing system, or it was registered but the alert was ignored, that is key evidence of malpractice. You should request a written copy of these records immediately after the accident to prevent the risk of later alteration.

(3) Emergency Treatment Records — The Time and Type of Epinephrine Administration

The time and dose of epinephrine administration after anaphylactic shock, and whether and how CPR was performed, must remain in the records. In the Busan District Court case, the administration of ephedrine instead of epinephrine, the improper CPR, and the 35-minute delay in transfer were each found to be independent acts of malpractice. Whether the times recorded in the emergency treatment records match the measures actually taken becomes the core issue.

Practical Checkpoints

• Disclose your allergy and adverse-reaction history at every hospital visit, and check that the disclosure was entered in the medical records. If you only say it verbally and it is not in the records, proving it in a dispute is difficult.

• If you suspect the dose you were prescribed is inappropriate, keep the prescription and the medicine envelope, and check the approved dose for that ingredient yourself on the Ministry of Food and Drug Safety's drug information site (drug.mfds.go.kr). Exceeding the permitted dose is itself the starting point of malpractice.

• If anaphylactic shock occurred, check whether the emergency drug the medical staff administered was epinephrine. If an inappropriate drug such as ephedrine was used instead of epinephrine, you can assert emergency-response malpractice separately (Busan District Court 2017Gahap52562).

• If you have a history of severe hypersensitivity to contrast media (fainting, fecal incontinence, bronchospasm, etc.), be sure to tell the physician before a CT scan and ask whether an alternative test such as MRI is possible. Where only premedication was given and alternative tests were not considered, even criminal liability of the physician has been recognized (Seoul Western District Court 2023Godan1504).

• When receiving chemotherapy, always check whether the nurse verifies your name and date of birth before administration. If this step was omitted and another patient's drug was administered, a wrong-patient administration error is recognized (Incheon District Court 2020Gahap58969).

• If signs of infection such as high fever, chills, or a sharp rise in white blood cells appeared after surgery and the medical staff merely observed the course without prescribing potent antibiotics or arranging transfer, check the period of delay and the response taken through the medical records. A delayed antibiotic prescription is itself malpractice (Ulsan District Court 2014Gahap17387).

• Even if a medication error is found, you will not be compensated unless you prove causation between that error and the loss. Before litigation, you should design with a medical-specialist lawyer what evidence you will use to prove causation (Busan District Court 2023Gadan344234).

"Drug side effects can happen to anyone." When the hospital says that, patients give up. But if the drug was administered even though the allergy was recorded in the chart, if something other than epinephrine was used when shock came, if an anticancer drug meant for another patient was given, or if antibiotics were delayed despite signs of infection — this is medical malpractice that left a foreseeable risk unaddressed. Side effects and malpractice are not the same thing.